机械英文参考文献及翻译
机械外文翻译外文文献英文文献机械臂动力学与控制的研究
外文出处：Ellekilde, L. -., & Christensen, H. I. (2009). Control of mobile manipulator using the dynamical systems approach. Robotics and Automation, Icra 09, IEEE International Conference on (pp.1370 - 1376). IEEE.机械臂动力学与控制的研究拉斯彼得Ellekilde摘要操作器和移动平台的组合提供了一种可用于广泛应用程序高效灵活的操作系统,特别是在服务性机器人领域。
在机械臂众多挑战中其中之一是确保机器人在潜在的动态环境中安全工作控制系统的设计。
在本文中,我们将介绍移动机械臂用动力学系统方法被控制的使用方法。
该方法是一种二级方法, 是使用竞争动力学对于统筹协调优化移动平台以及较低层次的融合避障和目标捕获行为的方法。
I介绍在过去的几十年里大多数机器人的研究主要关注在移动平台或操作系统，并且在这两个领域取得了许多可喜的成绩。
今天的新挑战之一是将这两个领域组合在一起形成具有高效移动和有能力操作环境的系统。
特别是服务性机器人将会在这一方面系统需求的增加。
大多数西方国家的人口统计数量显示需要照顾的老人在不断增加,尽管将有很少的工作实际的支持他们。
这就需要增强服务业的自动化程度，因此机器人能够在室内动态环境中安全的工作是最基本的。
图、1 一台由赛格威RMP200和轻重量型库卡机器人组成的平台这项工作平台用于如图1所示,是由一个Segway与一家机器人制造商制造的RMP200轻机器人。
其有一个相对较小的轨迹和高机动性能的平台使它适应在室内环境移动。
库卡工业机器人具有较长的长臂和高有效载荷比自身的重量,从而使其适合移动操作。
当控制移动机械臂系统时,有一个选择是是否考虑一个或两个系统的实体。
在参考文献[1]和[2]中是根据雅可比理论将机械手末端和移动平台结合在一起形成一个单一的控制系统。
机械手设计英文参考文献原文翻译
翻译人：王墨墨山东科技大学文献题目：Automated Calibration of Robot Coordinatesfor Reconfigurable Assembly Systems翻译正文如下：针对可重构装配系统的机器人协调性的自动校准T.艾利，Y.米达，H.菊地，M.雪松日本东京大学，机械研究院，精密工程部摘要为了实现流水工作线更高的可重构性，以必要设备如机器人的快速插入插出为研究目的。
当一种新的设备被装配到流水工作线时，应使其具备校准系统。
该研究使用两台电荷耦合摄像机，基于直接线性变换法，致力于研究一种相对位置/相对方位的自动化校准系统。
摄像机被随机放置，然后对每一个机械手执行一组动作。
通过摄像机检测机械手动作，就能捕捉到两台机器人的相对位置。
最佳的结果精度为均方根值0.16毫米。
关键词：装配，校准，机器人1 介绍21世纪新的制造系统需要具备新的生产能力，如可重用性，可拓展性，敏捷性以及可重构性[1]。
系统配置的低成本转变，能够使系统应对可预见的以及不可预见的市场波动。
关于组装系统，许多研究者提出了分散的方法来实现可重构性[2][3]。
他们中的大多数都是基于主体的系统，主体逐一协同以建立一种新的配置。
然而，协同只是目的的一部分。
在现实生产系统中，例如工作空间这类物理问题应当被有效解决。
为了实现更高的可重构性，一些研究人员不顾昂贵的造价，开发出了特殊的均匀单元[4][5][6]。
作者为装配单元提出了一种自律分散型机器人系统，包含多样化的传统设备[7][8]。
该系统可以从一个系统添加/删除装配设备，亦或是添加/删除装配设备到另一个系统；它通过协同作用，合理地解决了工作空间的冲突问题。
我们可以把该功能称为“插入与生产”。
在重构过程中，校准的装配机器人是非常重要的。
这是因为，需要用它们来测量相关主体的特征，以便在物理主体之间建立良好的协作关系。
这一调整必须要达到表1中所列到的多种标准要求。
机械设计专业外文文献翻译
机械设计专业外文文献翻译general。
however。
materials that are easy to machine have high machinability。
while those that are difficult to machine have low XXX。
microstructure。
and mechanical properties。
as well as the XXX。
material。
and wear resistance.XXX factors。
cutting speed。
feed rate。
and depth of cut also play XXX the amount of heat generated in the cutting zone and decreasing the time that the cutting tool is in contact with the XXX。
at high cutting speeds。
tool wear and cutting forces can increase。
which can ce tool life and surface finish quality.Feed rate and depth of cut also XXX the amount of material that is removed and the forces that are generated during cutting。
Higher feed rates and deeper cuts can improve material removal rates。
but they can also increase cutting forces and heat n。
which can ce tool life and surface finish quality.Overall。
机械类外文文献及翻译
机械类外文文献及翻译(文档含中英文对照即英文原文和中文翻译)原文：GEAR AND SHAFT INTRODUCTIONAbstract:The important position of the wheel gear and shaft can't falter in traditional machine and modern machines.The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, using for many situations respectively. So we must be the multilayers to the understanding of the wheel gear and shaft in many ways .Key words: Wheel gear; ShaftIn the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case ofbevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid.The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed heli : cal gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle areequal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A single-enveloping gearing is onein which the gear wraps around or partially encloses the worm.. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 0-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 0 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered.Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squr gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often go : od design practice to go to the spiral bevel gear, which is the bevel counterpart of thehelical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered.It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears.A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time.The word “shaft” covers numerous v ariations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirt rotating shaft is often called a spindle.When either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. The reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safe; it is almost always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the power-transmission elements, such as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the deflection and bending stress.Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment,and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability.Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two in : ertias I and I traveling at the respective angular velocities W and W, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for eath geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the heat-dissipating surfaces. The various types of clutches and brakes may be classified as fllows:. Rim type with internally expanding shoes. Rim type with externally contracting shoes. Band type. Disk or axial type. Cone type. Miscellaneous typeThe analysis of all type of friction clutches and brakes use the same general procedure. The following step are necessary:. Assume or determine the distribution of pressure on the frictional surfaces.. Find a relation between the maximum pressure and the pressure at any point. Apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.Miscellaneous clutches include several types, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet-shaped, or gear-tooth-shaped. Sometimes a great many teeth or jaws are used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements.Although positive clutches are not used to the extent of the frictional-contact type, they do have important applications where synchronous operation is required.Devices such as linear drives or motor-operated screw drivers must run to definite limit and then come to a stop. An overload-release type of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal.An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overrun” bec ause the driver is stopped or because another source of power increase the speed of the driven. This : type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats machined around the periphery. Driving action is obtained by wedging the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth.Magnetic fluid clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. By varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained.齿轮和轴的介绍摘要:在传统机械和现代机械中齿轮和轴的重要地位是不可动摇的。
机械设计类英文文献及翻译
The Sunflower Seed Huller and Oil PressBy Jeff Cox-- from Organic Gardening, April 1979, Rodale PressIN 2,500 SQUARE FEET, a family of four can grow each year enough sunflower seed to produce three gallons of homemade vegetable oil suitable for salads or cooking and 20 pounds of nutritious, dehulled seed -- with enough broken seeds left over to feed a winter's worth of birds.The problem, heretofore, with sunflower seeds was the difficulty of dehulling them at home, and the lack of a device for expressing oil from the seeds. About six months ago, we decided to change all that. The job was to find out who makes a sunflower seed dehuller or to devise one if none were manufactured. And to either locate a home-scale oilseed press or devise one. No mean task.Our researches took us from North Dakota -- hub of commercial sunflower activity in the nation -- to a search of the files in the U.S. Patent Office, with stops in between. We turned up a lot of big machinery, discovered how difficult it is to buy really pure, unrefined vegetable oils, but found no small-scale equipment to dehull sunflowers or press out their oil. The key to success, however, was on our desk the whole time. In spring 1977, August Kormier had submitted a free-lance article describing how he used a Corona grain mill to dehull his sunflower seeds, and his vacuum cleaner exhaust hose to blow the hulls off the kernels. A second separation floated off the remaining hulls, leaving a clean product. We'd tried it, but because some kernels were cracked and the process involved drying, we hadn't been satisfied. Now we felt the best approach was to begin again with what we learned from Mr. Kormier and refine it.Staff Editor Diana Branch and Home Workplace Editor Jim Eldon worked with a number of hand- and electric-powered grain mills. While the Corona did a passable job, they got the best results with the C.S. Bell #60 hand mill and the Marathon Uni Mill, which is motor-driven. "I couldn't believe my eyes the first time I tried the Marathon," Diana says. "I opened the stones to 1/8th inch, and out came a bin full of whole kernels and hulls split right at the seams. What a thrill that was!"She found that by starting at the widest setting,and gradually narrowing the opening, almost every seed was dehulled. The stones crack the hulls open, then rub them to encourage the seed away from the fibrous lining. The Bell hand mill worked almost as well. "As long as the stones open at least as wide as the widest unhulled seed, any mill will work," she says.Because the seed slips through the mill on its flat side, grading is an important step to take before dehulling. We made three sizing boxes. Thefirst is 1/4-inch hardware cloth [wire screen]. The second is two layers of1/4-inch cloth, moved slightly apart to narrow the opening in one direction, and the third is two layers of screen adjusted to make a still-smaller opening. Since the smallest unhulled seeds are about the size of the largest hulled kernels, the grading step prevents these undersized seeds from passing through unhulled. Processed together at a closer setting, the smallest seeds hulled out.Jim Eldon's workshop is littered with strange-looking pieces of apparatus. They represent initial attempts to build a workable winnowing box, using Kormier's vacuum exhaust idea for a source of air. Jim, Fred Matlack and Diana finally made a box with a Plexiglas front, through which they could observe what was happening.They cut a hole in the back of the box with a sliding cover to regulate the air pressure, and fiddled with various arrangements of baffles. The result was a stream of hulls exiting through one hole while the kernels fell to the bottom of the box. Now they were ready to try a five-pound sample of unhulled sunflower seeds to see how much they could recover.The five pounds were graded and dehulled, then winnowed. We got about one hull for every ten kernels in the final, winnowed product. These are easily picked out. They usually contain kernels still held behind the fibrous strings of the hull. Their weight prevents them from blowing out with the empty hulls. We found that bug-eaten seeds do blow away with the chaff, which was a bonus for cleanliness of the final product. Toss the hulls to the birds, who will find broken seeds among them.Starting with 80 ounces of unhulled seed, we ended up with 41-1/4 ounces of edible whole seeds, 1.8 ounces of damaged seeds suitable for animal feed, and 36.6 ounces of hulls. It took us about an hour. Notbad.Sunflower seeds store perfectly in the hulls, but they deteriorate more rapidly when shelled out. The grain mill dehuller and winnowing box give the gardener a way to have the freshest possible seeds for eating at all times of the year. With the construction of one more piece of equipment -- the oil press -- he can have absolutely fresh, unrefined, polyunsaturated sunflower oil for salads, mayonnaise and cooking.Most light, refined vegetable oils have been extracted using hexane, a form of naphtha. The oil is then heated to boil off the hexane. Lye is dumped into it. It's washed with steam, then heated to remove odors and taste before being laced with preservatives and stabilizers. It may feel oily in the mouth, but you might as well taste air. No so with fresh-made sunflower oil -- it's deliciously yet subtly nutty in flavor, adding unsurpassed flavor to salads.There's good reason to believe that sunflower oil may become the #1 vegetable oil in the U.S. in a few years. It's already #1 in health-conscious Europe. Corn oil has already caught on here for health reasons, and sunflower oil is so much better. Sunflower oil's 70 percent polyunsaturate is just under safflower, with corn oil bringing up the rear with 55 percent. And sunflowers yield 40 percent oil, soybeans only 20 percent.Our oil press isrelatively simple, but it must be welded together. Check the construction directions for details. The press consists of a welded tubular frame which accepts a three-ton hydraulic jack. You may already have one. If not, it can be purchased at most auto and hardware stores for about $16. A metal canister with holes drilled in its sides and one end welded shut holds the mashed sunflower seeds. A piston is inserted in the canister and then inverted and slipped over a pedestal on the frame. The jack is set in place, and the pressure gradually increased over half an hour. The oil drips from the sides of the canister into a tray -- the bottom of a plastic jug slipped over the pedestal works fine -- which empties the oil into a cup. You can filter the oil with a coffee filter to remove pieces of seed and other fine particles that would burn if the oil were used for cooking. If it's for salads or mayonnaise, there's no need to filter it.We first tried using "confectionary" sunflower seeds for oil. These are the regular eating kernels we're used to seeing. They give less than half as much oil as the oilseed types of sunflower. Although you can use confectionary types such as MAMMOTH RUS- SIAN for oil, don't expect to get more than an ounce and a half from a pound of seed. Oilseed produces three or more ounces of oil from a pound of seed and is well worth planting along with confectionary-type seeds. Oilseed has another big advantage -- to prepare it, you can put the whole, unhulled seed into a blender and whiz it until it forms a fine meal, while confectionary seeds must be dehulled first. The entire sequence of grading, dehulling and winnowing is avoided with oilseed.Oil types produce about a tenth of a pound of seed per head in commercial production. Gardeners, with their better soil and care, invariably do better than that. Our conservative estimate is that 1,280 plants will be enough for three gallons of oil. Spaced one foot apart in rows two feet apart, 1,280 oilseed plants will take a space 40-by-56 feet, or 80-by-28 if you want a more rectangular patch to face south.We worked in pound batches, since the canister just holds one pound of mash. After blending, we heated it to 170 degrees F. (77 deg C) by placing it in a 300-degree F. (149 deg C) oven and stirring it every five minutes for 20 minutes. Heating gets the oil flowing and doubles the yield of oil. In case you're wondering,"cold-pressed" oils sold commercially are also heated, and some are subjected to the entire chemical process. The term has no firm meaning within the industry, according to the literature we've surveyed.Heating does not change the structure of fats. It will not turn polyunsaturated fats into saturated fats. In fact, Dr. Donald R. Germann in his book, "TheAnti-Cancer Diet", says that "... an unsaturated fat must be heated to high temperatures -- above 425 degrees F. or 200 degrees C. -- at least 8 or 10 times before any shift toward saturation occurs..." Dean C. Fletcher, Ph.D., of the American Medical Association Department of Foods and Nutrition in Chicago, says, "It's true that either high temperature or repeated heatingdoes change the nature of some of the unsaturated oil molecules. (But) the flavor of the oil changes as these chemical changes occur, spoiling its taste. This effect is probably more profound than any of the physiological changes the altered oil might produce within the body."From 500 gm. of heated mash, we pressed 89 gm. of oil, 89 percent of the entire amount available and twice as much as we could press from unheated oil! The decision is up to you whether or not to heat the mash, but that extra 50 percent seems like an awful lot, especially when the whole technique is so labor intensive. The oil should be stored in the refrigerator, and it's probably best to use it within a month, since it has no preservatives. Mayonnaise made with such fresh oils should be kept refrigerated and used within two weeks. The leftover cake, still containing 50 percent of its oil, is a nutritious addition to your dishes, and makes excellent feed for animals or winter birds. Store the pressed cake in the freezer.We're talking then about a sunflower patch with two kinds of plants -- confectionary such as MAMMOTH RUSSIAN and oilseed such as PEREDOVIK. The oilseed plants should be grown 12 inches apart in rows two feet apart. Four average confectionary heads yield about a pound of unhulled seed. You'll need about 35 pounds of unhulled seed, or 140plants-worth, to yield 20 pounds of hulled kernels, about what a family of four will use in a year. That many plants can be grown in an area 26-by-10 feet. That's 260 square feet. Put that together with the 2,240 square feet for the oilseed sunflowers, and you need a patch about 2,500 square feet -- 25 100-foot rows -- to keep yourself supplied year-round with super nutrition and unsurpassable taste.Winnowing Machine For Sunflower SeedsThe winnowing machine operates on the age-old principle of blowing the chaff away from the heavy grain with a controlled current of air.The unit uses a household or shop-type vacuum cleaner for its air supply. A vacuum cleaner was used as a power source because it can supply a large volume of air over an extended period of time, and most homes and farms have a vacuum cleaner.A cloth bag has been attached to the chaff chute to catch the chaff as it is separated from the seed. The bag allows the hulls to be collected and greatly reduces the amount of waste material normally blown into the air by conventional systems.The unit has been constructed in such a way that the cloth bag and cleaner box can be placed inside the seed box, making a compact package for storage.Tools Required1. Table Saw2. Drill Press3. Band Saw4. Saber SawProcedure (cleaner box)1 . Cut out the two sides of the cleaner box from 1/4-inch plywood.2. Cut out the six interior pieces of the cleaner box from 3/4 x 3-1/2-inch select pine.3. Assemble the cleaner box elements with glue and nails.4. Cut four 1/4-inch square strips of pine four inches long.5. Glue the strips around the end of the chaff chute.6. Sand all surfaces and edges.7. Finish with clear lacquer finish.Procedure (seed box)1. Cut two pieces of pine /34" x 5 /12 x 15 inches for the sides.2. Cut two pieces of pine 3/4 x 5-1/2 x inches for the top and bottom.3. Plow a /14 x 1/4 groove for the front and back panels in all four pieces.4. Rip the top board to 5 inches so that the front panel can slide into the grooves in the side boards.5. Rabbet both ends of each 15-inch side piece to accept the top and bottom boards.6. Drill a hole in the left side board 2-1/2 inches from the top. The size of the hole is determined by the vacuum cleaner hose fitting.7. Cut a 3-1/4 x 4 inch hole in the top 1/2 inch from the right end. This hole will accept the cleaner box.8. Cut two pieces of pine for the baffle.9. Drill two 1-inch holes in the bottom of the baffle box.10. Cut a piece of 1/4 x 8-1/2 x 14 inch plywood for the back panel.11. Cut a 3-inch hole, centered 1-7/8 inches from the top and left sides of the plywood back.12. Assemble the sides, baffles, top, bottom, and back panel with glue and nails.13. Cut an 8-7/16 x 15-3/4-inch piece of Plexiglas for the front.14. Cut a one-inch radius on the top corners of the front.and sand the edges.15. Drill a one-inch thumb hole centered 7/8 inch from the top edge.16. Cut a 3-1/2-inch disk of 1/4-inch plywood for the vent cover.17. Drill a 3/16-inch hole 3/8 inch from the edge of the disk.18. Mount the disk over the vent with a #10 x 1-inch screw.19. Sand all surfaces and edges of the, box.20. Finish with clear lacquer finish.MaterialsCleaner Box2 -- 7-3/4 x 7-1/2 x 3/4" plywood (sides)6 -- 3/4 x 3-1/2 x 24" for all members (baffles)4 -- 1/4 x 1/4 x 4" pine (chute cleats)22 -- 1" x 18 ga. headed nailsWhite vinyl glueClear lacquer finishSeed Box2 -- 3/4' x 5-1/2 x 15" select pine (sides)2 -- 3/4 x 5-1/2 x 8-1/2" select pine (top and bottom)1 -- 3/4 x 3-1/2 x 4-1/2" select pine (baffle)1 -- 3/4 x 4-1/2 x 4-1/2" select pine (baffle)1 -- 1/4 x 8-1/2 x 14" plywood (back)1 -- 1/4 x 3-1/2" dia. plywood (control valve)1 -- 1/4' x 8-7/16 x 15-1/4" Plexiglas (front)1 - #10 x 1" flat head screw18 - 4d finish nailsWhite vinyl glueClear lacquer finish1 -- 17 x 31" cloth laundry bagSunflower Seed Oil PressThe press was designed so that homesteaders can produce sunflower oil from their own seeds. The oil can be pressed as is or heated to 170 degrees F., which doubles oil yield.Both methods require the seed to be ground to fine powder. If you are pressing the oil seed variety, a meat grinder or electric blender will do an excellent job of grinding the seed. The confectionary type of seed will require the seed to be hulled and winnowed before it is ground. A food mill with the stones set at the coarse setting can be used to accomplish this step. The ground kernels are placed in the cylinder with the piston closing the bottom portion of the cylinder.The cylinder is mounted in the press frame and a three-ton hydraulic jack is used to supply the pressure.Because of the great pressures created by the hydraulic jack, it is important that the frame be properly constructed and firmly mounted to the work surface before the pressing operation begins. The following instructions can be given to a welder.Tools Required1. Power Hacksaw2. Metal Band Saw3. Metal Lathe4. Drill Press5. Belt or Disk Grinder6. Arc Welder7. Hand ClampsProcedure (Frame)1. Cut two pieces of 1-3/4" O.D. x 1-3/8" I.D. x 24-1/2 inch long tubing for the uprights.2. Cut one piece of 1-3/4" O.D. x 1-3/8" I.D. x 6-1/2 inch long tubing for the center tube.3. Cut one 3/4" x 2-3/4 x 5-1/2 inch steel bar for the top cross member.4. Cut two pieces of 1-3/4 x 1-3/4 x 8 inch angle iron for the base members.5. Drill two 9/32-inch holes in each base member 1/2 inch from the outer edges.6. Weld the base members, tubes and cross member together as per the drawing.7. Grind all edges to remove any burrs.8. Paint the frame.9. If a mounting board is desired, cut a piece of pine 1-1/4 x 6-1/2 x 12 inches long.10. Center the frame on the board and mark the location of the four mounting holes.11. Drill four 7/8-inch holes 1/4-inch deep to accept the T-nuts.12. Drill four 5/16-inch holes through the mounting board using the same centers created by the 7/8-inch holes.13. Round the edges of the base and sand all surfaces.14. Install four 1/4-20 T-nuts.15. Finish the base with clear lacquer finish.16. Assemble the base to the frame using four 1/4-20 x 1-1/4-inch round head bolts.Procedure (Cylinder)1. Cut a piece of 3-1/2" O.D. x 3-1/4" I.D. tubing 5-3/8 inches long.2. Face both ends on the lathe.3. Cut out a 3-1/2-inch round disk from 1/4-inch plate steel.4. Weld the disk to one end of the tube.5. Drill a series of 3/32-inch holes around the side of the tube on 1/2-inch centers.6. Remove all burrs on the inside and outside of the tube.Procedure (Piston)1. Cut out a 3-3/8-inch disk of 1/4-inch plate steel.2. Cut a 1-3/8" O.D. x 1-1/8" I.D. piece of tubing 1-1/8 inches long.3. Face both ends of the tube.4. Weld the tube in the center of the 3-3/8-inch disk. All welds should be made on the inside of the tube.5. Mount the piston in the lathe and turn the disk to fit the inside diameter of the cylinder. This will be about 3-15/64 inches in diameter.6. Remove any sharp edges.Procedure (Collector Ring)1. Cut the bottom out of a one-gallon plastic bottle. The cut line should be approximately 1-1/2 inches from the bottom of the bottle.2. Make a 1/8 x 1 inch slot at one edge of the bottom outside ring. This will allow the oil to pour into a receiving cup.3. Cut a 1-3/4-inch hole in the center of the bottom, so that the unit will fit over the center tube in the frame.MaterialsFrame2 -- 1-3/4 O.D. x 1-3/8 I.D. x 24-1/2" long H.R.S. (frame tubes)1 -- 1-3/4 O.D. x 1-3/8 I.D. x 6-1/2 inch long H.R.S. (center tube)1 -- 3/4 x 2-3/4 x 5-1/2" flat bar H.R.S. (top cross member)2 -- 1-3/4 x 1-3/4 x 8" angle iron H.R.S. (base members)1 -- 1-1/4 x 6-1/2 x 12" #2 white pine (wood base)4 -- 1/4-20 x 1-1/4 R.H. mounting bolts4 -- 1/4-20 T-nutsBlack enamel for frame (finishing material)Clear lacquer finish for wood base3 -- 1/8" dia. welding rodsCylinder1 -- 1/4 x 3-1/2" dia. C.R.S. disk (top)1 -- 3-1/2 O.D. x 3-1/4 I.D. C.R.S. tube (cylinder)1 -- 1/8 dia. welding rodPiston1 -- 1/4 x 3-3/8 D.A. C.R.S. disk (piston top)1 -- 1-1/4 O.D. x 1 I.D. x 1" long H.R.S. (piston tube)1 -- 1/8 dia. welding rodCollector Ring1 -- Bottom from a one-gallon plastic bottle (oil collector ring)葵花籽脱壳机和油压机由Jeff考克斯-从有机园艺，1979年4月，罗代尔新闻2,500平方尺，一个四口之家每年可以长到足以产生三种葵花籽国产蔬菜沙拉或烹调油和20磅的营养丰富，适合脱皮加仑种子 - 与遗留养活一个冬天的产值，破碎的种子鸟类。
机械外文文献及翻译
与机械相关的外文及翻译Multidisciplinary Design Optimization of Modular Industrial Robots by Utilizing High Level CAD Templates1、IntroductionIn the design of complex and tightly integrated engineering products, it is essential to be able to handle interactions between different subsystems of multidisciplinary nature [1]. To achieve an optimal design, a product must be treated as a complete system instead of developing subsystems independently [2]. MDO has been established as a convincing concurrent design optimization technique in development of such complex products [3,4].Furthermore, it has been pointed out that, regardless of discipline, basically all analyses require information that has to be extracted from a geometry model [5]. Hence, according to Bow-cutt [1], in order to enable integrated design analysis and optimization it is of vital importance to be able to integrate an automated parametric geometry generation system into the design framework. The automated geometry generation is a key enabler for so-called geometry-in-the-loop[6] multidisciplinary design frameworks, where the CAD geometries can serve as framework integrators for other engineering tools.To eliminate noncreative work, methods for creation and automatic generation of HLCt have been suggested by Tarkian [7].The principle of high HLCts is similar to high level primitives(HLP) suggested by La Rocca and van Tooren [8], with the exception that HLCts are created and utilized in a CAD environment.Otherwise, the basics of both HLP and HLCt can, as suggested byLa Rocca, be compared to parametric LEGOV Rblocks containing a set of design and analysis parameters. These are produced and stored in libraries, giving engineers or a computer agent the possibility to first topologically select the templates and then modify the morphology, meaning theshape,of each template parametrically.2、Multidisciplinary Design FrameworkMDO is a “systematic approach to design space exploration”[17], the implementation of which allows the designer to map the interdisciplinary relations that exist in a system. In this work, the MDO framework consists of a geometry model, a finite element(FE) model, a dynamic model and a basic cost model. The geometry model provides the analysis tools with geometric input. The dynamic model requires mass properties such as mass, center of gravity, and inertia. The FE model needs the meshed geometry of the robot as well as the force and torque interactions based on results of dynamic simulations.High fidelity models require an extensive evaluation time which has be taken into account. This shortcoming is addressed by applying surrogate models for the FE and the CAD models. The models are briefly presented below. 2.1 High Level CAD Template—Geometry ModelTraditionally, parametric CAD is mainly focused on morphological modifications of the geometry. However, there is a limit to morphological parameterization as follows:•The geometries cannot be radically modified.•Increased geometric complexity greatly increases parameterization complexity.The geometry model of the robot is generated with presaved HLCts, created in CATIA V5. These are topologically instantiated with unique internal design variables. Topological parameterization allows deletion, modification, and addition of geometricelements which leads to a much greater design space captured.Three types of HLCts are used to define the industrial robot topologically; Datum HLCt which includes wireframe references required for placement for the Actuator HLCTs and Structure HLCts, as seen Fig.2.Fig. 2 An industrial robot (left) and a modular industrial robot(right) The names of the references that must be provided for each HLCt instantiation are stored in the knowledge base (see Appen-dix A.4), which is searched through by the inference engine. In Appendix A, pseudocode examples describes how the references are retrieved and how they are stored in the knowledge base.The process starts by the user defining the number of degrees of freedom (DOF) of the robot (see Fig. 3) and is repeated until the number of axis (i) is equal to the user defined DOF.In order to instantiate the first Structure HLCt, two Datum and two actuator instances are needed. References from the two Datum instances help orienting the structure in space, while the geometries of the actuator instances, at both ends of the link, are used to construct the actuator attachments, as seen in Figs. 2 and 3. For the remaining links, only one new instance of both datum and actuator HLCts are required, since the datum and actuator instances from adjacent links are already available.Appendix A.2 shows a pseudocode example of an instantiation function. The first instantiated datum HLCt is defined with reference to the absolute coordinate system. The remaining datum HLCt instances are placed in a sequential order, where the coordinate system of previous instances is used as reference for defining the position in space according to user inputs (see also AppendixA.3). Furthermore, the type of each actuator and structure instance is user defined.Fig. 3 The high level CAD template instantiation process Since it is possible to create new HLCts in the utilized CAD tool, the users are not forced to merely choose from the templates available. New HLCts can be created, placed in the database and parametrically inserted into the models.2.2 Dynamic ModelThe objective of performing dynamic simulation of a robot is to evaluate system performance, such as predicting acceleration and time performance, but it also yields loads on each actuated axis, needed for actuator lifetime calculations and subsequent stress analysis based on FE calculations. Thedynamic model in the outlined framework is developed in Modelica using Dymola, and it constitutes a seven-axis robot arm based on the Modelica Standard library [18].The dynamic model receives input from the geometry model,as well as providing output to the FE model, which is further described in Sec. 2.3. However, to better understand the couplings between the models, the Newton –Euler formulation will be briefly discussed. In this formulation, the link velocities and acceleration are iteratively computed, forward recursivelyWhen the kinematic properties are computed, the force and torque interactions between the links are computed backward recursively from the last to the first link2.3 FE Surrogate ModelTo compute the structural strength of the robot, FE models for each robot link is created utilizing CATIA V5, see Fig. 4. For each HLCt, mesh and boundary conditions are manually preprocessed in order to allow for subsequent automation for FE-model creation. The time spent on preprocessing each FE-model is thus extensive. Nonetheless, the obtained parametric FE-model paves way for automated evaluation of a wide span of concepts. Each robot link is evaluated separately with the load conditions extracted from the dynamicmodel. The force (fi-11and fi) and torque (ţi-1and ti) are applied on the surfaceswhere the actuators are attached.2.4 Geometric Surrogate Models.Surrogate models are numerically efficient models to determine the relation between inputs and o utputs of a model [19]. The input variables for the proposed application are the morphological variables thickness and link height as well as a topological variable actuator type. The outputs of the surrogate models are mass m, Inertia I, and center of gravity ri,ci.To identify the most suitable type of surrogate model for the outlined problem, a range of surrogate models types are created and evaluated using 50 samples. The precision of each surrogate model is compared with the values of the original model with 20 new samples. The comparison is made using the relative average absolute error (RAAE) and relative maximum absolute error (RMAE) as specified by Shan et al. [20], as well as the normalized root mean square error (NRMSE), calculated as seen in Eq. (3). All precision metrics are desired to be as low as possible, since low values mean that the surrogate model is accurateThe resulting precision metrics can be seen in Appendix B and the general conclusion is that anisotropic kriging [21], neural networks [22], and radialbasis functions [23] are the most promising surrogate models. To investigate the impact of increasing number of samples, additional surrogate models of those three are fitted using 100 samples, and the results compiled in Appendix B. The resulting NRMSEs for 50 and 100 samples for anistotropic kriging, neural networks, and radial basis functions can be seen in Fig.5. The figures inside the parentheses indicate the number of samples used to fit the surrogate models.Fig. 5 Graph of the NRMSEs for different surrogate models,fitted using 50 and 100 samplesAccording to Fig. 5, anisotropic kriging outperforms the other surrogate models and the doubling of the number of samples usedfor fitting the surrogate model increases the precision dramatically.2.5 FE Surrogate ModelsFor generating FE surrogate models, the anisotropic kriging was also proven to be the most accurate compared to the methods evaluated in Sec. 2.4. Here, one surrogate model is created for each link. Inputs are thickness,actuators, force (fi-11and fi) and torque (ţi-1and ti). The output for eachsurrogate model is maximum stress (MS).A mean error of approximately 9% is reached when running 1400 samples for each link. The reason for the vast number of samples, compared to geometry surrogate models, has to do with a much larger design space.利用高水平CAD模板进行模块化工业机器人的多学科设计优化1 介绍指出,除了规则,基本上所有的分析都需要信息,而这些信息需要从一个几何模型中提取。
机械类英语论文及翻译
Mechanical DesignAbstract:A machine is a combination of mechanisms and other components which transforms, transmits. Examples are engines, turbines, vehicles, hoists, printing presses, washing machines, and movie cameras. Many of the principles and methods of design that apply to machines also apply to manufactured articles that are not true machines. The term "mechanical design" is used in a broader sense than "machine design" to include their design. the motion and structural aspects and the provisions for retention and enclosure are considerations in mechanical design. Applications occur in the field of mechanical engineering, and in other engineering fields as well, all of which require mechanical devices, such as switches, cams, valves, vessels, and mixers.Keywords: Mechanical Design ；Rules for Design ；Design ProcessThe Design ProcessDesigning starts with a need real.Existing apparatus may need improvements in durability, efficiency, weight, speed, or cost. New apparatus may be needed to perform a function previously done by men, such as computation, assembly, or servicing. With the objective wholly or partly.In the design preliminary stage, should allow to design the personnel fullyto display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.When the general shape and a few dimensions of the several components become apparent, analysis can begin in earnest. The analysis will have as its objective satisfactory or superior performance, plus safety and durability with minimum weight, and a competitive cost. Optimum proportions and dimensions will be sought for each critically loaded section, together with a balance between the strengths of the several components. Materials and their treatment will be chosen. These important objectives can be attained only by analysis based upon the principles of mechanics, such as those of static for reaction forces and for the optimum utilization of friction; of dynamics for inertia, acceleration, and energy; of elasticity and strength of materials for stress and deflection; of physical behavior of materials; and of fluid mechanics for lubrication and hydrodynamic drives. The analyses may be made by the same engineer who conceived the arrangement of mechanisms, or, in a large company, they may be made by a separate analysis division or research group. Design is a reiterative and cooperative process, whetherdone formally or informally, and the analyst can contribute to phases other than his own. Product design requires much research and development. Many Concepts of an idea must be studied, tried, and then either used or discarded. Although the content of each engineering problem is unique, the designers follow the similar process to solve the problems.Product liability suits designers and forced in material selection, using the best program. In the process of material, the most common problems for five (a) don't understand or not use about the latest application materials to the best information, (b) failed to foresee and consider the reasonable use material may (such as possible, designers should further forecast and consider due to improper use products. In recent years, many products liability in litigation, the use of products and hurt the plaintiff accused manufacturer, and won the decision), (c) of the materials used all or some of the data, data, especially when the uncertainty long-term performance data is so, (d) quality control method is not suitable and unproven, (e) by some completely incompetent persons choose materials.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to thesuitable procedure, may greatly reduce the lawsuit the quantity.May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding.Finally, a design based upon function, and a prototype may be built. If its tests are satisfactory, the initial design will undergo certain modifications that enable it to be manufactured in quantity at a lower cost. During subsequent years of manufacture and service, the design is likely to undergo changes as new ideas are conceived or as further analyses based upon tests and experience indicate alterations. Sales appeal.Some Rules for DesignIn this section it is suggested that, applied with a creative attitude, analyses can lead to important improvements and to the conception and perfection of alternate, perhaps more functional, economical,and durable products.To stimulate creative thought, the following rules are suggested for the designer and analyst. The first six rules are particularly applicable for the analyst.1. A creative use of need of physical properties and control process.2. Recognize functional loads and their significance.3. Anticipate unintentional loads.4. Devise more favorable loading conditions.5. Provide for favorable stress distribution and stiffness with minimum weight.6. Use basic equations to proportion and optimize dimensions.7. Choose materials for a combination of properties.8. Select carefully, stock and integral components.9. Modify a functional design to fit the manufacturing process and reduce cost.10. Provide for accurate location and noninterference of parts in assembly.Machinery design covers the following contents.1. Provides an introduction to the design process , problem formulation ,safety factors.2. Reviews the material properties and static and dynamic loading analysis ,Including beam , vibration and impact loading.3. Reviews the fundamentals of stress and defection analysis.4. Introduces fatigue-failure theory with the emphasis on stress-life approaches to high-cycle fatigue design, which is commonly used in the design of rotation machinery.5. Discusses thoroughly the phenomena of wear mechanisms, surface contact stresses ,and surface fatigue.6. Investigates shaft design using the fatigue-analysis techniques.7. Discusses fluid-film and rolling-element bearing theory and application8. Gives a thorough introduction to the kinematics, design and stress analysis of spur gears , and a simple introduction to helical ,bevel ,and worm gearing.9. Discusses spring design including compression ,extension and torsion springs.10. Deals with screws and fasteners including power screw and preload fasteners.11. Introduces the design and specification of disk and drum clutches and brakes.Machine DesignThe complete design of a machine is a complex process. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.One of the first steps in the design of any product is to select the material from which each part is to be made. Numerous materials are available to today's designers. The function of the product, its appearance, the cost of thematerial, and the cost of fabrication are important in making a selection. A careful evaluation of the properties of a. material must be made prior to any calculations.Careful calculations are necessary to ensure the validity of a design. In case of any part failures, it is desirable to know what was done in originally designing the defective components. The checking of calculations (and drawing dimensions) is of utmost importance. The misplacement of one decimal point can ruin an otherwise acceptable project. All aspects of design work should be checked and rechecked.The computer is a tool helpful to mechanical designers to lighten tedious calculations, and provide extended analysis of available data. Interactive systems, based on computer capabilities, have made possible the concepts of computer aided design (CAD) and computer-aided manufacturing (CAM). How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process. Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved.This generally is through the oral discussion, the schematic diagram and the writing material carries on.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainlycannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.外文论文翻译译文机械设计摘要：机器是由机械装置和其它组件组成的。
机械类英文文献+翻译
机械类英文文献+翻译20.9 MACHINABILITYThe machinability of a material usually defined in terms of four factors:1、Surface finish and integrity of the machined part;2、Tool life obtained;3、Force and power requirements;4、Chip control.Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone.Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. In manufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below.20.9.1 Machinability Of SteelsBecause steels are among the most important engineering materials (as noted in Chapter 5), their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels.Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primary shear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in resulfurized steels.Phosphorus in steels has two major effects. It strengthens the ferrite, causingincreased hardness. Harder steels result in better chip formation and surface finish. Note that soft steels can be difficult to machine, with built-up edge formation and poor surface finish. The second effect is that increased hardness causes the formation of short chips instead of continuous stringy ones, thereby improving machinability.Leaded Steels. A high percentage of lead in steels solidifies at the tip of manganese sulfide inclusions. In non-resulfurized grades of steel, lead takes the form of dispersed fine particles. Lead is insoluble in iron, copper, and alumin um and their alloys. Because of its low shear strength, therefore, lead acts as a solid lubricant (Section 32.11) and is smeared over the tool-chip interface du ring cutting. This behavior has been verified by the presence of high concentra tions of lead on the tool-side face of chips when machining leaded steels.When the temperature is sufficiently high-for instance, at high cutting spee ds and feeds (Section 20.6)—the lead melts directly in front of the tool, acting as a liquid lubricant. In addition to this effect, lead lowers the shear stress in the primary shear zone, reducing cutting forces and power consumption. Lead can be used in every grade of steel, such as 10xx, 11xx, 12xx, 41xx, etc. Le aded steels are identified by the letter L between the second and third numeral s (for example, 10L45). (Note that in stainless steels, similar use of the letter L means 〝low carbon,〞a condition that improves their corrosion resistance.)However, because lead is a well-known toxin and a pollutant, there are se rious environmental concerns about its use in steels (estimated at 4500 tons of lead consumption every year in the production of steels). Consequently, there is a continuing trend toward eliminating the use of lead in steels (lead-free ste els). Bismuth and tin are now being investigated as possible substitutes for lea d in steels.Calcium-Deoxidized Steels. An important development is calcium-deoxidize d steels, in which oxide flakes of calcium silicates (CaSo) are formed. These f lakes, in turn, reduce the strength of the secondary shear zone, decreasing tool-chip interface and wear. Temperature is correspondingly reduced. Consequently, these steels produce less crater wear, especially at high cutting speeds.Stainless Steels. Austenitic (300 series) steels are generally difficult to mac hine. Chatter can be s problem, necessitating machine tools with high stiffness.However, ferritic stainless steels (also 300 series) have good machinability. M artensitic (400 series) steels are abrasive, tend to form a built-up edge, and req uire tool materials with high hot hardness and crater-wear resistance. Precipitati on-hardening stainless steels are strong and abrasive, requiring hard and abrasio n-resistant tool materials.The Effects of Other Elements in Steels on Machinability. The presence of aluminum and silicon in steels is always harmful because these elements com bine with oxygen to form aluminum oxide and silicates, which are hard and a brasive. These compounds increase tool wear and reduce machinability. It is es sential to produce and use clean steels.Carbon and manganese have various effects on the machinability of steels, depending on their composition. Plain low-carbon steels (less than 0.15% C) c an produce poor surface finish by forming a built-up edge. Cast steels are mor e abrasive, although their machinability is similar to that of wrought steels. To ol and die steels are very difficult to machine and usually require annealing pr ior to machining. Machinability of most steels is improved by cold working, w hich hardens the material and reduces the tendency for built-up edge formation.Other alloying elements, such as nickel, chromium, molybdenum, and vana dium, which improve the properties of steels, generally reduce machinability. T he effect of boron is negligible. Gaseous elements such as hydrogen and nitrog en can have particularly detrimental effects on the properties of steel. Oxygen has been shown to have a strong effect on the aspect ratio of the manganese sulfide inclusions; the higher the oxygen content, the lower the aspect ratio an d the higher the machinability.In selecting various elements to improve machinability, we should consider the possible detrimental effects of these elements on the properties and strengt h of the machined part in service. At elevated temperatures, for example, lead causes embrittlement of steels (liquid-metal embrittlement, hot shortness; see Se ction 1.4.3), although at room temperature it has no effect on mechanical prop erties.Sulfur can severely reduce the hot workability of steels, because of the fo rmation of iron sulfide, unless sufficient manganese is present to prevent suchformation. At room temperature, the mechanical properties of resulfurized steels depend on the orientation of the deformed manganese sulfide inclusions (aniso tropy). Rephosphorized steels are significantly less ductile, and are produced so lely to improve machinability.20.9.2 Machinability of Various Other MetalsAluminum is generally very easy to machine, although the softer grades te nd to form a built-up edge, resulting in poor surface finish. High cutting speed s, high rake angles, and high relief angles are recommended. Wrought aluminu m alloys with high silicon content and cast aluminum alloys may be abrasive; they require harder tool materials. Dimensional tolerance control may be a pro blem in machining aluminum, since it has a high thermal coefficient of expans ion and a relatively low elastic modulus.Beryllium is similar to cast irons. Because it is more abrasive and toxic, t hough, it requires machining in a controlled environment.Cast gray irons are generally machinable but are. Free carbides in castings reduce their machinability and cause tool chipping or fracture, necessitating to ols with high toughness. Nodular and malleable irons are machinable with hard tool materials.Cobalt-based alloys are abrasive and highly work-hardening. They require sharp, abrasion-resistant tool materials and low feeds and speeds.Wrought copper can be difficult to machine because of built-up edge form ation, although cast copper alloys are easy to machine. Brasses are easy to ma chine, especially with the addition pf lead (leaded free-machining brass). Bronz es are more difficult to machine than brass.Magnesium is very easy to machine, with good surface finish and prolong ed tool life. However care should be exercised because of its high rate of oxi dation and the danger of fire (the element is pyrophoric).Molybdenum is ductile and work-hardening, so it can produce poor surfac e finish. Sharp tools are necessary.Nickel-based alloys are work-hardening, abrasive, and strong at high tempe ratures. Their machinability is similar to that of stainless steels.Tantalum is very work-hardening, ductile, and soft. It produces a poor surf ace finish; tool wear is high.Titanium and its alloys have poor thermal conductivity (indeed, the lowest of all metals), causing significant temperature rise and built-up edge; they can be difficult to machine.Tungsten is brittle, strong, and very abrasive, so its machinability is low, although it greatly improves at elevated temperatures.Zirconium has good machinability. It requires a coolant-type cutting fluid, however, because of the explosion and fire.20.9.3 Machinability of Various MaterialsGraphite is abrasive; it requires hard, abrasion-resistant, sharp tools.Thermoplastics generally have low thermal conductivity, low elastic modul us, and low softening temperature. Consequently, machining them requires tools with positive rake angles (to reduce cutting forces), large relief angles, small depths of cut and feed, relatively high speeds, and proper support of the work piece. Tools should be sharp.External cooling of the cutting zone may be necessary to keep the chips f rom becoming 〝gummy〞and sticking to the tools. Cooling can usually be a chieved with a jet of air, vapor mist, or water-soluble oils. Residual stresses m ay develop during machining. To relieve these stresses, machined parts can be annealed for a period of time at temperatures ranging from to ( to ), and th en cooled slowly and uniformly to room temperature.Thermosetting plastics are brittle and sensitive to thermal gradients during cutting. Their machinability is generally similar to that of thermoplastics.Because of the fibers present, reinforced plastics are very abrasive and are difficult to machine. Fiber tearing, pulling, and edge delamination are significa nt problems; they can lead to severe reduction in the load-carrying capacity of the component. Furthermore, machining of these materials requires careful rem oval of machining debris to avoid contact with and inhaling of the fibers.The machinability of ceramics has improved steadily with the development of nanoceramics (Section 8.2.5) and with the selection of appropriate processi ng parameters, such as ductile-regime cutting (Section 22.4.2).Metal-matrix and ceramic-matrix composites can be difficult to machine, d epending on the properties of the individual components, i.e., reinforcing or wh iskers, as well as the matrix material.20.9.4 Thermally Assisted MachiningMetals and alloys that are difficult to machine at room temperature can be machined more easily at elevated temperatures. In thermally assisted machinin g (hot machining), the source of heat—a torch, induction coil, high-energy bea m (such as laser or electron beam), or plasma arc—is forces, (b) increased too l life, (c) use of inexpensive cutting-tool materials, (d) higher material-removal rates, and (e) reduced tendency for vibration and chatter.It may be difficult to heat and maintain a uniform temperature distribution within the workpiece. Also, the original microstructure of the workpiece may be adversely affected by elevated temperatures. Most applications of hot machi ning are in the turning of high-strength metals and alloys, although experiment s are in progress to machine ceramics such as silicon nitride.SUMMARYMachinability is usually defined in terms of surface finish, tool life, force and power requirements, and chip control. Machinability of materials depends n ot only on their intrinsic properties and microstructure, but also on proper sele ction and control of process variables.20.9 可机加工性一种材料的可机加工性通常以四种因素的方式定义：1、分的表面光洁性和表面完整性。
机械设计外文文献翻译、中英文翻译
机械设计外文文献翻译、中英文翻译unavailable。
The first step in the design process is to define the problem and XXX are defined。
the designer can begin toXXX evaluated。
and the best one is XXX。
XXX.Mechanical DesignA XXX machines include engines。
turbines。
vehicles。
hoists。
printing presses。
washing machines。
and XXX and methods of design that apply to XXXXXX。
cams。
valves。
vessels。
and mixers.Design ProcessThe design process begins with a real need。
Existing apparatus may require XXX。
efficiency。
weight。
speed。
or cost。
while new apparatus may be XXX。
To start。
the designer must define the problem and XXX。
ideas and concepts are generated。
evaluated。
and refined until the best one is XXX。
XXX.XXX。
assembly。
XXX.During the preliminary design stage。
it is important to allow design XXX if some ideas may seem impractical。
they can be corrected early on in the design process。
英文文献翻译(机械类)
冷轧厂工作轴过早发生故障的分析济南钢铁有限公司技术中心，济南250101，中国收到2006年9月12日，在2007年1月15日收到，2007年1月18日2007年5月23日网上提供澳大利亚，新南威尔士州2522，Wollongong，Wollongong大学，机械学院，材料和机械电子工程概述在本文中，对几个冷连轧机工作轴过早失效进行了调查。
为了研究工作轴表面特性和破坏机理，化学成分，微观结构和轧轴材料的硬度进行了研究。
已计算在工作轴剥落面积的压力，确定应力状态。
在研究中，轧轴磨损和损坏的原因已经查明。
对工作轴表面图像进行了研究，发现了已损坏的轧轴磨损特性的特点。
人们已经发现，经营的因素和冶金缺陷将影响在冷轧带钢轧轴的使用寿命。
2007 Elsevier B.V保留所有权利。
关键词：穿；工作轴冷轧；应力分布1.介绍目前，冷轧带钢生产上的冷连轧带钢轧机或倒车的冷连轧机工作轴破坏为[1]非圆形变形[2]。
应用于冷连轧，板形好，型材和平整度[3,4]得到控制模型的基础上。
在冷连轧机工作轴发挥主导作用，使带钢的变形来实现所需的形状，轮廓和尺寸。
然而，工作轴在极其恶劣的条件下运作，在经营成本的冷连轧机的最重要环节之一，是有关工作轴[5]。
工作轴磨损的材料，变形，热凸度，氧化铁皮及带钢表面粗糙度等的影响，[6-14]已查处，并为混合润滑摩擦模型[15]。
工作轴的磨损，影响热轧带钢质量和工作轴使用寿命显着。
在轧钢工作轴的过程中，受高循环荷载和水平高的耐磨性。
与热轧相比，冷轧钢轧制材料的抗变形能力是非常高。
在轧轴咬轧轴表面受到高压力是大于10000 MPa和进一步剪应力产生摩擦[16]在轴/带接口。
工作轴过早失效滚动不仅增加成本，而且还轧机停机时间，生产力显着影响。
伪造合金钢工作轴过早失败的原因可能是操作技术和冶金轧轴因素的综合影响。
经营的因素，包括轧制负荷，润滑，轧制速度，运营商的经验，如轧制参数的选择。
工作轴的质量，包括非金属夹杂物的存在，铸造缺陷和相变[16]。
机械类文献翻译英文版
Major diameter Pitch diameter Minor diameter Pitch p
45° chamfer
Root Crest
Thread angle 2α
Figure 8–2
Basic profile for metric M and M J threads. d ϭ major diameter dr ϭ minor diameter dp ϭ pitch diameter pϭ√ pitch H ϭ 23 p
Figure 8–1
Terminology of screw threads. Sharp vee threads shown for clarity; the crests and roots are actually flattened or rounded during the forming operation.
The helical-thread screw was undoubtably an extremely important mechanical invention. It is the basis of power screws, which change angular motion to linear motion to transmit power or to develop large forces (presses, jacks, etc.), and threaded fasteners, an important element in nonpermanent joints. This book presupposes a knowledge of the elementary methods of fastening. Typical methods of fastening or joining parts use such devices as bolts, nuts, cap screws, setscrews, rivets, spring retainers, locking devices, pins, keys, welds, and adhesives. Studies in engineering graphics and in metal processes often include instruction on various joining methods, and the curiosity of any person interested in mechanical engineering naturally results in the acquisition of a good background knowledge of fastening methods. Contrary to first impressions, the subject is one of the most interesting in the entire field of mechanical design. One of the key targets of current design for manufacture is to reduce the number of fasteners. However, there will always be a need for fasteners to facilitate disassembly for whatever purposes. For example, jumbo jets such as Boeing’s 747 require as many as 2.5 million fasteners, some of which cost several dollars apiece. To keep costs down, aircraft manufacturers, and their subcontractors, constantly review new fastener designs, installation techniques, and tooling. The number of innovations in the fastener field over any period you might care to mention has been tremendous. An overwhelming variety of fasteners are available for the designer’s selection. Serious designers generally keep specific notebooks on fasteners alone. Methods of joining parts are extremely important in the engineering of a quality design, and it is necessary to have a thorough understanding of the performance of fasteners and joints under all conditions of use and design.
机械专业文献带翻译
机械专业文献带翻译Title: Research and Development of a Novel Mechanical Device for Automated Assembly of Small Parts。
Abstract:The assembly of small parts is a time-consuming and labor-intensive process, often requiring skilled workers to perform the task. In order to improve efficiency and reduce costs, a novel mechanical device for automated assembly of small parts has been developed. This device is capable of handling a variety of small parts with high precision and speed, and can significantly reduce the time and cost required for assembly.Introduction:The assembly of small parts is a critical process in many industries, including electronics, automotive, and medical device manufacturing. This process often requiresskilled workers to perform the task, which can be time-consuming and costly. In addition, human error can lead to defects and quality issues, further increasing costs and reducing efficiency.To address these challenges, a novel mechanical device for automated assembly of small parts has been developed. This device is capable of handling a variety of small parts with high precision and speed, and can significantly reduce the time and cost required for assembly.Design and Development:The mechanical device for automated assembly of small parts consists of several key components, including a feeder, a manipulator, and a control system. The feeder is responsible for delivering small parts to the manipulator, which then assembles the parts according to a predetermined pattern. The control system coordinates the movements of the feeder and manipulator, ensuring that the assembly process is carried out with high precision and speed.The design of the manipulator is particularly important, as it must be capable of handling a wide range of smallparts with varying shapes and sizes. The manipulatorconsists of a series of grippers and suction cups, whichcan be adjusted to accommodate different types of parts.The grippers and suction cups are controlled by a series of motors and sensors, which ensure that the parts are picked up and assembled accurately.Testing and Evaluation:The mechanical device for automated assembly of small parts has been tested extensively in a laboratory setting, and has demonstrated high levels of precision and speed.The device is capable of handling a wide range of small parts, including electronic components, screws, and bolts.In addition, the device has been shown to significantly reduce the time and cost required for assembly, compared to manual assembly methods.Future Directions:The mechanical device for automated assembly of small parts has significant potential for use in a variety of industries, including electronics, automotive, and medical device manufacturing. Further research and development is needed to optimize the design and performance of the device, and to explore its potential for use in new applications.Conclusion:The development of a novel mechanical device for automated assembly of small parts has the potential to revolutionize the assembly process in many industries. This device is capable of handling a wide range of small parts with high precision and speed, and can significantly reduce the time and cost required for assembly. Further research and development is needed to optimize the design and performance of the device, and to explore its potential for use in new applications.。
机械英文参考文献及翻译
机械英文参考文献及翻译第一篇：机械英文参考文献及翻译Abstract: With a focus on the intake tower of the Yanshan Reservoir, this paper discusses the method of modeling in the 3D CAD software SolidWorks and the interface processing between SolidWorks and the ANSYS code, which decreases the difficulty in modeling complicated models in ANSYS.In view of the function of the birth-death element and secondary development with APDL(ANSYS parametric design language), a simulation analysis of the temperature field and thermal stress during the construction period of the intake tower was conveniently conducted.The results show that the temperature rise is about29.934 □ over 3 or 4 days.The temperature differences betweena ny two points are less than 24 □.The thermal stress increases with the temperature difference and reaches its maximum of 1.68 MPa at the interface between two concrete layers.Key words: SolidWorks;ANSYS;APDL;birth-death element;temperature field;thermal stress 1 Introduction Mass concrete is widely used in civil and hydraulic engineering nowadays, and its thermal stress increasingly attracts attention during design and construction.It is necessary to analyze the temperature field and thermal stress of important mass concrete structures with both routine methods and the finite element method(FEM).Some researchers have done a large amount of simulation analyses using FEM software(Tatro 1985;Barrett et al.1992;Kawaguchi and Nakane 1996;Zhu and Xu 2001;Zhu 2006), but difficulties in these methods remain.There are two main difficulties:(1)Most mass concrete structures are complex and difficult to model with FEM software.(2)Complete simulation is difficult with FEM softwarebecause of the complex construction processes and boundary conditions of concrete.The structure of the intake tower of the Yanshan Reservoir is complex.It is 34.5 m high and there is a square pressure tunnel at the bottom, the side length of which is 6 m.The intake tower was modeled in the 3D CAD software SolidWorks and imported into ANSYS with an interface tool.Then, using the APDL program, analysis of the temperature field and thermal stress during construction was conducted.2 Modeling in SolidWorks and interface processing between SolidWorks and ANSYS 2.1 Modeling in SolidWorks SolidWorks is a CAD/CAE/CAM/PDM desktop system, and the first 3D mechanical CAD software in Windows developed by the SolidWorks company.It provides product-level automated design tools(Liu and Ren 2005).The outside structure of the intake tower is simple but the internal structure is relatively complex.Therefore, the process of modeling is undertaken from the inside to the outside.The integrated and internal models of the intake tower are shown in Fig.1 and Fig.2.图片Fig.1 Integrated model Fig.2 Cross section 2.2 Interface processing between SolidWorks and ANSYS ANSYS is a type of large universal finite element software that has a powerful ability to calculate and analyze aspects of structure, thermal properties, fluid, electromagnetics, acoustics and so on.In addition, the interface of ANSYS can be used to import the CAD model conveniently(Zhang 2005), which greatly reduces the difficulties of dealing with complex models.The interface tools are given in Table 1.Table 1 CAD software packages and preferred interface tools 图表1After modeling in SolidWorks, it is necessary to save the model as a type of Parasolid(*.x_t)so as to import it into ANSYS correctly.Then, in ANSYS, the importing of the model iscompleted with the command “PARAIN, Name, Extension, Path, Entity, FMT, Scale” or the choice of “FileDImportDPARA...” in the GUI interface.There are two means of importing: selecting or not selecting “Allow Defeaturing”，the differences of which are shown in Fig.3 and Fig.4.图片Fig.3 Importing with defeaturing Fig.4 Importing without defeaturing 3 Analysis of temperature field of intake tower The temperature analysis of the intake tower during the construction period involves aspects of the temperature field and thermal stress.The calculation must deal with the problems of simulation of layered construction, dynamic boundary conditions, hydration heat, dynamic elasticity modulus, autogenous volume deformation of concrete and thermal creep stress, which are difficult to simulate directly in ANSYS.APDL is a scripting language based on the style of parametric variables.It is used to reduce a large amount of repetitive work in analysis(Gong and Xie 2004).This study carried out a simulation analysis of the temperature field considering nearly all conditions of construction, using the birth-death element and programming with APDL.3.1 Solving temperature field principle 3.1.1 Unsteady temperature field analysis The temperature of concrete changes during the construction period due to the effect of hydration heat of cement.This problem can be expressed as a heat conduction problem with internal heat sources in the area.The unsteady temperature field T(x, y, z,D)is written as(Zhu 1999): 公式1where □ is the thermal conductivity of concrete, c is the specific heat of concrete, □ is the density of concrete, □ is the adiabatic temperature rise of concrete, and □ is the age of concrete.In the 3D unsteady temperature field analysis, the functional form I e(T)is 公式2 where □R is a subfield of unit e;□0is the area on surface D , which is only in boundary units;c □ □ □□;□ is the exothermic coefficient;the thermal diffusivity c □ □ □ □;and isthe air temperature.a T3.1.2 Initial conditions and boundary conditions of concrete The initial conditions are the distribution laws of the initial transient temperature of internal concrete.The calculated initial temperature of concrete is 10 □.The index formula of hydration heat of cement is 公式 3 where t is the pouring time.The conversion between Q and □ is 公式4 The boundary conditions involve the laws of interaction between concrete and the surrounding medium.When concrete is exposed to the air, the boundary condition is 公式5 where n is the normal direction.Both and a T □ are constants or variables(Ashida and Tauchert 1998;Lin and Cheng 1997).During the maintenance period, the insulation materials of concrete are steel formworks and straws, and the exothermic coefficient of the outer surface is reduced as equivalent processing.The exothermic coefficients of the steel formwork and the straw are 45 kJ/(m2h+0)and 10 kJ/(m2h+0)，respectively.Based on the local temperature during construction, the following formula can be fitted according to the temperature variation curve: 公式63.2 Analysis of temperature field in ANSYS The simulation scheme of layered construction, which is based on the real construction scheme, is shown in T able 2.The pouring days in Table 2 are all the total days of construction for each layer.A layer is not poured until the former layer is poured.图表2The feature points are selected in every layer above the base plate.The maximum temperatures and the temperature curvesare given in Table 3 and Fig.5, respectively.Table 3 Coordinates and maximum temperature of feature points 图表3 图片5 Fig.5 Maximum temperature curves Fig.5 shows that the maximum temperature of each layer occurs on the 3rd or 4th day after pouring, and then the temperature decreases with time, which is consistent with related literature(Lin and Cheng 1997;Luna and Wu 2000;Wu and Luna 2001).In Fig.5, the numbers of feature points from 2 to 8 are corresponding to their maximum temperature curves from Nodetemp 2 to Nodetemp 8, and the curve of Nodetemp 9 is the air temperature curve.Feature point 8, the maximum temperature of which is 29.934 □ , occurrin g on the 206th day of the total construction period, shows the maximum temperature rise during the construction period.Feature point 4, the coordinates of which are(16.4, 16.0, 5.0), shows the maximum temperature difference of 23.5340.4 Analysis of thermal stress of intake tower Expansion or contraction of the structure occurs during heating and cooling.If the expansion or contraction of different parts is inconsistent, then thermal stress occurs.The indirect method was adopted in this study: the temperature of nodes was first obtained in analysis of the temperature field, and then applied to the structure as a body load.4.1 Selection of calculating parameters The parameters of concrete are given in Table 4.The elasticity modulus is 公式7 T able 4 Parameters of concrete 图表4 The creep effect must be considered in analysis of temperature stress.The creep degree of concrete is influenced by the cement type, water-cement ratio and admixture.The formula of the creep degree is 公式8 Considering the creep degree, the formula of the elasticity modulus is adjusted to be 公式94.2 Analysis of thermal stress in ANSYS As in analysis of thetemperature field, feature points were selected in each layer above the base plate, and their coordinates were the same as those in the temperature field analysis.The maximum thermal stress of each point is shown in Table 5.Feature point 9, the coordinates of which are(17.4, 10.8, 8.0), is the point with the maximum thermal stress.Table 5 Maximum thermal stress of feature points 图表5The thermal stress curves of feature points are shown in Fig.6.图片6Fig.6 Maximum stress curves In Fig.6, the numbers of feature points from 2 to 9 are corresponding to their maximum stress curves from S1_2 to S1_9, and the S1_10 curve is the ultimate tensile stress o f concrete.The formula of concrete’s ultimate tensile stress is 公式10 The figures and table show that the maximum thermal stress of the intake tower is 1.68 MPa, occurring on the 90th day of the construction period, which is the end of the third layer maintenance period and the beginning of the pouring of the fourth layer.It is known that the thermal stress increases with the temperature difference.Feature point 9 is located at the interface between the third layer and the fourth layer.Thus, it is postulated that the maximum thermal stress is caused by the instantaneous temperature difference between two layers in the pouring period.In Fig.6, the S1_10 curve shows the ultimate tensile stress curve of concrete.It is known that the maximum thermal stress of each point in the intake tower during the construction period is less than the ultimate tensile stress of concrete.5 Conclusions ⑴ The problem of the interface between SolidWorks and ANSYS is resolved in this study, realizing an effective combination of the advantages of both SolidWorks and ANSYS and providing a basis for analysis in ANSYS.(2)Using abirth-death element and considering layered construction, dynamic boundary conditions, hydration heat, the dynamic elasticity modulus, autogenous volume deformation and creep of concrete, the temperature field and thermal stress during the construction period are conveniently obtained due to the virtues of secondary development with APDL.(3)The analysis of temperature shows that the temperature of concrete rises rapidly in the early stage of construction, reaches a maximum value of 29.934 □ on the 3rd or 4th day after pouring, drops thereafter, and is consistent with air temperature after about 30 days.The thermal stress increases with the temperature difference, and the occurrence time of the maximum thermal stress is consistent with that of the maximum temperature difference.The maximum thermal stress occurs at the interface of new and old layers and is caused by the instantaneous temperature difference, the value of which is 1.68 MPa.(4)The maximum thermal stress is less than the ultimate tensile stress of concrete, which illustrates that the curing measures in construction are effective.Meanwhile, in view of the fact that the maximum thermal stress occurs at the interface of new and old layers, more attention should be paid to it, especially when there is a long interval of time between the pouring of different layers.References Ashida, F., and Tauchert, T.R.1998.An inverse problem for determination of transient surface temperature from piezoelectric sensor measurement.Journal of Applied Mechanics, 65(2), 367-373.[doi:10.1115/1.2789064] Barrett, P.R., Foadian, H., James, R.J., and Rashid, Y.R.1992.Thermal-structural analysis methods for RCC dams.Proceedings of the Conference of Roller Concrete III, 407-422.San Diego: ASCE.Gong, S.G., and Xie, mands and Parametric Programming inANSYS.Beijing: China Machine Press.(in Chinese)Kawaguchi, T., and Nakane, S.1996.Investigations on determining thermal stress in massive concrete structures.ACI Materials Journal, 93(1), 96-101.Lin, J.Y., and Cheng, T.F.1997.Numerical estimation of thermal conductivity from boundary temperature measurements.Numerical Heat Transfer, 32(2), 187-203.[doi:10.1080/***87] Liu, L.J., and Ren, J.P.2005.Application of the secondary development in SolidWorks.Mechanical Management and Development,(1), 74-75.(in Chinese)Luna, R., and Wu, Y.2000.Simulation of temperature and stress fields during RCC dam construction.Journal of Construction Engineering and Management, ASCE, 126(5), 381-388.[doi: 10.1061/(ASCE)0733-9364(2000)126:5(381)] Tatro, S.B.and Schrader, E.K.1985.Thermal consideration for roller compacted concrete.ACI Structural Journal, 82(2), 119-128.Wu, Y., and Luna, R.2001.Numerical implementation of temperature and creep in mass concrete.Finite Elements in Analysis and Design, 37(2), 97-106.[doi:10.1016/S0168-874X(00)00022-6] Zhang, J.2005.Interface design between AutoCAD and ANSYS.Chinese Quarterly of Mechanics, 26(2), 257-262.(in Chinese)Zhu, B.F.1999.Thermal Stresses and Temperature Control of Mass Concrete.Beijing: China Electric Power Press.(in Chinese)Zhu, B.F., and Xu, P.2001.Methods for stress analysis simulating the construction process of high concrete dams.Dam Engineering, 6(4), 243-260.Zhu, B.F.2006.Current situation and prospect of temperature control and cracking prevention technology for concrete dam.Journal of Hydraulic Engineering, 37(12), 1424-1432.(in Chinese)第二篇：英文文献翻译（模版）在回顾D和H的文章时，我愿意第一个去单独地讨论每一篇，然后发表一些总体的观点。
(完整版)机械类外文文献翻译
文献翻译英文原文：NOVEL METHOD OF REALIZING THE OPTIMAL TRANSMISSION OF THE CRANK-AND-ROCKER MECHANISM DESIGN Abstract: A novel method of realizing the optimal transmission of the crank-and-rocker mechanism is presented. The optimal combination design is made by finding the related optimal transmission parameters. The diagram of the optimal transmission is drawn. In the diagram, the relation among minimum transmission angle, the coefficient of travel speed variation, the oscillating angle of the rocker and the length of the bars is shown, concisely, conveniently and directly. The method possesses the main characteristic. That it is to achieve the optimal transmission parameters under the transmission angle by directly choosing in the diagram, according to the given requirements. The characteristics of the mechanical transmission can be improved to gain the optimal transmission effect by the method. Especially, the method is simple and convenient in practical use.Keywords：Crank-and-rocker mechanism, Optimal transmission angle, Coefficient of travel speed variationINTRODUCTIONBy conventional method of the crank-and-rocker design, it is very difficult to realize the optimal combination between the various parameters for optimal transmission. The figure-table design method introduced in this paper can help achieve this goal. With given conditions, we can, by only consulting the designing figures and tables, get the relations between every parameter and another of the designed crank-and-rocker mechanism. Thus the optimal transmission can be realized.The concerned designing theory and method, as well as the real cases of its application will be introduced later respectively.1ESTABLISHMENT OF DIAGRAM FOR OPTIMAL TRANSMISSION DESIGNIt is always one of the most important indexes that designers pursue to improve the efficiency and property of the transmission. The crank-and-rocker mechanism is widely used in the mechanical transmission. How to improve work ability and reduce unnecessary power losses is directly related to the coefficient of travel speed variation, the oscillating angle of the rocker and the ratio of the crank and rocker. The reasonable combination of these parameters takes an important effect on the efficiency and property of the mechanism, which mainly indicates in the evaluation of the minimum transmission angle.The aim realizing the optimal transmission of the mechanism is how to find themaximum of the minimum transmission angle. The design parameters are reasonably combined by the method of lessening constraints gradually and optimizing separately. Consequently, the complete constraint field realizing the optimal transmission is established.The following steps are taken in the usual design method. Firstly, the initial values of the length of rocker 3l and the oscillating angle of rocker ϕ are given. Then the value of the coefficient of travel speed variation K is chosen in the permitted range. Meanwhile, the coordinate of the fixed hinge of crank A possibly realized is calculated corresponding to value K .1.1 Length of bars of crank and rocker mechanismAs shown in Fig.1, left arc G C 2 is the permitted field of point A . Thecoordinates of point A are chosen by small step from point 2C to point G .The coordinates of point A are 02h y y c A -= (1)22A A y R x -= (2)where 0h , the step, is increased by small increment within range(0,H ). If the smaller the chosen step is, the higher the computational precision will be. R is the radius of the design circle. d is the distance from 2C to G .2cos )2cos(22cos 33ϕθϕϕ⎥⎦⎤⎢⎣⎡--+=l R l d (3) Calculating the length of arc 1AC and 2AC , the length of the bars of themechanism corresponding to point A is obtained [1,2].1.2 Minimum transmission angle min γMinimum transmission angle min γ(see Fig.2) is determined by the equations [3]322142322min 2)(cos l l l l l l --+=γ (4) 322142322max 2)(cos l l l l l l +-+=γ (5) max min180γγ-︒=' (6) where 1l ——Length of crank(mm)2l ——Length of connecting bar(mm)3l ——Length of rocker(mm)4l ——Length of machine frame(mm)Firstly, we choose minimum comparing min γ with minγ'. And then we record all values of min γ greater than or equal to ︒40 and choose the maximum of them.Secondly, we find the maximum of min γ corresponding to any oscillating angle ϕ which is chosen by small step in the permitted range (maximum of min γ is different oscillating angle ϕ and the coefficient of travel speed variation K ).Finally, we change the length of rockerl by small step similarly. Thus we3γcorresponding to the different length of bars, may obtain the maximum ofmindifferent oscillating angle ϕand the coefficient of travel speed variation K.Fig.3 is accomplished from Table for the purpose of diagram design.It is worth pointing out that whatever the length of rocker 3l is evaluated, the location that the maximum of min γ arises is only related to the ratio of the length of rocker and the length of machine frame 3l /4l , while independent of 3l .2 DESIGN METHOD2.1 Realizing the optimal transmission design given the coefficient of travelspeed variation and the maximum oscillating angle of the rockerThe design procedure is as follows.(1) According to given K and ϕ, taken account to the formula the extreme included angle θ is found. The corresponding ratio of the length of bars 3l /4l is obtained consulting Fig.3.︒⨯+-=18011K K θ (7) (2) Choose the length of rocker 3l according to the work requirement, the length of the machine frame is obtained from the ratio 3l /4l .(3) Choose the centre of fixed hinge D as the vertex arbitrarily, and plot an isosceles triangle, the side of which is equal to the length of rocker 3l (see Fig.4), andϕ=∠21DC C . Then plot 212C C M C ⊥, draw N C 1, and make angleθ-︒=∠9012N C C . Thus the point of intersection of M C 2 and N C 1 is gained. Finally, draw the circumcircle of triangle 21C PC ∆.(4) Plot an arc with point D as the centre of the circle, 4l as the radius. The arc intersections arc G C 2 at point A . Point A is just the centre of the fixed hinge of the crank.Therefore, from the length of the crank2/)(211AC AC l -= (8)and the length of the connecting bar112l AC l -= (9)we will obtain the crank and rocker mechanism consisted of 1l , 2l , 3l , and 4l .Thus the optimal transmission property is realized under given conditions.2.2 Realizing the optimal transmission design given the length of the rocker (or the length of the machine frame) and the coefficient of travel speed variationWe take the following steps.(1) The appropriate ratio of the bars 3l /4l can be chosen according to given K . Furthermore, we find the length of machine frame 4l (the length of rocker 3l ).(2) The corresponding oscillating angle of the rocker can be obtained consulting Fig.3. And we calculate the extreme included angle θ.Then repeat (3) and (4) in section 2.13 DESIGN EXAMPLEThe known conditions are that the coefficient of travel speed variation1818.1=K and maximum oscillating angle ︒=40ϕ. The crankandrockermechanism realizing the optimal transmission is designed by the diagram solution method presented above.First, with Eq.(7), we can calculate the extreme included angle ︒=15θ. Then, we find 93.0/43=l l consulting Fig.3 according to the values of θ and ϕ.If evaluate 503=l mm, then we will obtain 76.5393.0/504==l mm. Next, draw sketch(omitted).As result, the length of bars is 161=l mm,462=l mm,503=l mm,76.534=l mm.The minimum transmission angle is︒=--+=3698.462)(arccos 322142322min l l l l l l γ The results obtained by computer are 2227.161=l mm, 5093.442=l mm, 0000.503=l mm, 8986.534=l mm.Provided that the figure design is carried under the condition of the Auto CAD circumstances, very precise design results can be achieved.4 CONCLUSIONSA novel approach of diagram solution can realize the optimal transmission of the crank-and-rocker mechanism. The method is simple and convenient in the practical use. In conventional design of mechanism, taking 0.1 mm as the value of effective the precision of the component sizes will be enough.译文：认识曲柄摇臂机构设计的最优传动方法摘要：一种曲柄摇臂机构设计的最优传动的方法被提出。
机械设计外文文献及翻译
机械设计外文文献及翻译机械设计摘要：机器是由机械装置和其他组件组成的，用于转换或传递能量，例如发动机、涡轮机、车辆、起重机、印刷机、洗衣机、照相机和摄影机等。
许多原则和设计方法不仅适用于机器的设计，也适用于非机器的设计。
在机械工程和其他工程领域中，所有这些都需要机械设备，如开关、凸轮、阀门、船舶和搅拌机等。
关键词：设计流程、设计规则、机械设计设计流程在设计之前，应考虑机器的实际性，现有机器需要在耐用性、效率、重量、速度或成本方面得到改善。
新的机器必须具有以前机器所能执行的功能。
在设计的初始阶段，应允许设计人员充分发挥创造性，不受任何约束。
即使产生了许多不切实际的想法，也会在设计早期被改正。
只有这样，才不会阻碍创新思路。
通常还要提出几套设计方案，然后进行比较。
很可能在最终计划决定中，使用了某些不在计划之内的设想。
当外观特点和组件部分的尺寸特点分析透彻时，就可以全面设计和分析。
还要客观分析机器性能的优越性，以及其安全、重量、耐用性和成本竞争力。
每个至关重要的部分都要优化其比例和尺寸，同时也要保持与其他组成部分相协调。
还要选择原材料和处理原材料的方法。
通过力学原理来分析和实现这些重要特性，如静态反应的能量和摩擦力的最佳利用，动力惯性、加速动力和能量；包括弹性材料的强度、应力和刚度等材料的物理特性，以及流体润滑和驱动器的流体力学。
设计过程是重复和合作的过程，无论是正式还是非正式的，对设计者来说每个阶段都很重要。
最后，以图样为设计标准，并建立将来的模型。
如果测试符合要求，则对初步设计进行修改，以降低制造成本。
产品的设计需要不断探索和发展。
许多方案必须被研究、试验、完善，然后决定使用还是放弃。
虽然每个工程学问题的内容是独特的，但设计师可以按照类似的步骤来解决问题。
本文介绍了机械设计的复杂性和创造性，以及机械设计师所需要的基础知识。
在设计过程中，选择材料和进行精确计算都是必要的。
计算机辅助设计和制造技术已经成为现代机械设计的重要工具。
机械类外文文献及翻译
机械类外文文献及翻译(文档含中英文对照即英文原文和中文翻译)原文：GEAR AND SHAFT INTRODUCTIONAbstract:The important position of the wheel gear and shaft can't falter in traditional machine and modern machines.The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, using for many situations respectively. So we must be the multilayers to the understanding of the wheel gear and shaft in many ways .Key words: Wheel gear; ShaftIn the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case ofbevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid.The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed heli : cal gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle areequal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A single-enveloping gearing is onein which the gear wraps around or partially encloses the worm.. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 0-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 0 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered.Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squr gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often go : od design practice to go to the spiral bevel gear, which is the bevel counterpart of thehelical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered.It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears.A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time.The word “shaft” covers numerous v ariations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirt rotating shaft is often called a spindle.When either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. The reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safe; it is almost always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the power-transmission elements, such as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the deflection and bending stress.Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment,and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability.Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two in : ertias I and I traveling at the respective angular velocities W and W, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for eath geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the heat-dissipating surfaces. The various types of clutches and brakes may be classified as fllows:. Rim type with internally expanding shoes. Rim type with externally contracting shoes. Band type. Disk or axial type. Cone type. Miscellaneous typeThe analysis of all type of friction clutches and brakes use the same general procedure. The following step are necessary:. Assume or determine the distribution of pressure on the frictional surfaces.. Find a relation between the maximum pressure and the pressure at any point. Apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.Miscellaneous clutches include several types, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet-shaped, or gear-tooth-shaped. Sometimes a great many teeth or jaws are used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements.Although positive clutches are not used to the extent of the frictional-contact type, they do have important applications where synchronous operation is required.Devices such as linear drives or motor-operated screw drivers must run to definite limit and then come to a stop. An overload-release type of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal.An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overrun” bec ause the driver is stopped or because another source of power increase the speed of the driven. This : type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats machined around the periphery. Driving action is obtained by wedging the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth.Magnetic fluid clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. By varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained.齿轮和轴的介绍摘要:在传统机械和现代机械中齿轮和轴的重要地位是不可动摇的。
机械类外文文献翻译(中英文翻译)
机械类外文文献翻译(中英文翻译)英文原文Mechanical Design and Manufacturing ProcessesMechanical design is the application of science and technology to devise new or improved products for the purpose of satisfying human needs. It is a vast field of engineering technology which not only concerns itself with the original conception of the product in terms of its size, shape and construction details, but also considers the various factors involved in the manufacture, marketing and use of the product.People who perform the various functions of mechanical design are typically called designers, or design engineers. Mechanical design is basically a creative activity. However, in addition to being innovative, a design engineer must also have a solid background in the areas of mechanical drawing, kinematics, dynamics, materials engineering, strength of materials and manufacturing processes.As stated previously, the purpose of mechanical design is to produce a product which will serve a need for man. Inventions, discoveries and scientific knowledge by themselves do not necessarily benefit people; only if they are incorporated into a designed product will a benefit be derived. It should be recognized, therefore, that a human need must be identified before a particular product is designed.Mechanical design should be considered to be an opportunity to use innovative talents to envision a design of a product, to analyze the systemand then make sound judgments on how the product is to be manufactured. It is important to understand the fundamentals of engineering rather than memorize mere facts and equations. There are no facts or equations which alone can be used to provide all the correct decisions required to produce a good design.On the other hand, any calculations made must be done with the utmost care and precision. For example, if a decimal point is misplaced, an otherwise acceptable design may not function.Good designs require trying new ideas and being willing to take a certain amount of risk, knowing that if the new idea does not work the existing method can be reinstated. Thus a designer must have patience, since there is no assurance of success for the time and effort expended. Creating a completely new design generally requires that many old and well-established methods be thrust aside. This is not easy since many people cling to familiar ideas, techniques and attitudes. A design engineer should constantly search for ways to improve an existing product and must decide what old, proven concepts should be used and what new, untried ideas should be incorporated.New designs generally have "bugs" or unforeseen problems which must be worked out before the superior characteristics of the new designs can be enjoyed. Thus there is a chance for a superior product, but only at higher risk. It should be emphasized that, if a design does not warrant radical new methods, such methods should not be applied merely for the sake of change.During the beginning stages of design, creativity should be allowedto flourish without a great number of constraints. Even though many impractical ideas may arise, it is usually easy to eliminate them in the early stages of design before firm details are required by manufacturing. In this way, innovative ideas are not inhibited. Quite often, more than one design is developed, up to the point where they can be compared against each other. It is entirely possible that the design which is ultimately accepted will use ideas existing in one of the rejected designs that did not show as much overall promise.Psychologists frequently talk about trying to fit people to the machines they operate. It is essentially the responsibility of the design engineer to strive to fit machines to people. This is not an easy task, since there is really no average person for which certain operating dimensions and procedures are optimum.Another important point which should be recognized is that a design engineer must be able to communicate ideas to other people if they are to be incorporated. Communicating the design to others is the final, vital step in the design process. Undoubtedly many great designs, inventions, and creative works have been lost to mankind simply because the originators were unable or unwilling to explain their accomplishments to others. Presentation is a selling job. The engineer, when presenting a new solution to administrative, management, or supervisory persons, is attempting to sell or to prove to them that this solution is a better one. Unless this can be done successfully, the time and effort spent on obtaining the solution have been largely wasted.Basically, there are only three means of communication available tous. These are the written, the oral, and the graphical forms. Therefore the successful engineer will be technically competent and versatile in all three forms of communication. A technically competent person who lacks ability in any one of these forms is severely handicapped. If ability in all three forms is lacking, no one will ever know how competent that person is!The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, occasional failure should be expected because failure or criticism seems to accompany every really creative idea. There is a great deal to be learned from a failure, and the greatest gains are obtained by those willing to risk defeat. In the final analysis, the real failure would lie in deciding not to make the presentation at all. To communicate effectively, the following questions must be answered:(1) Does the design really serve a human need?(2) Will it be competitive with existing products of rival companies?(3) Is it economical to produce?(4) Can it be readily maintained?(5) Will it sell and make a profit?Only time will provide the true answers to the preceding questions, but the product should be designed, manufactured and marketed only with initial affirmative answers. The design engineer also must communicate the finalized design to manufacturing through the use of detail and assembly drawings.Quite often, a problem will occur during the manufacturing cycle [3].It may be that a change is required in the dimensioning or tolerancing of a part so that it can be more readily produced. This fails in the category of engineering changes which must be approved by the design engineer so that the product function will not be adversely affected. In other cases, a deficiency in the design may appear during assembly or testing just prior to shipping. These realities simply bear out the fact that design is a living process. There is always a better way to do it and the designer should constantly strive towards finding that better way.Designing starts with a need, real or imagined. Existing apparatus may need improvements in durability, efficiently, weight, speed, or cost. New apparatus may be needed to perform a function previously done by men, such as computation, assembly, or servicing. With the objective wholly or partly defined, the next step in design is the conception of mechanisms and their arrangements that will perform the needed functions.For this, freehand sketching is of great value, not only as a record of one's thoughts and as an aid in discussion with others, but particularly for communication with one's own mind, as a stimulant for creative ideas.When the general shape and a few dimensions of the several components become apparent, analysis can begin in earnest. The analysis will have as its objective satisfactory or superior performance, plus safety and durability with minimum weight, and a competitive east. Optimum proportions and dimensions will be sought for each critically loaded section, together with a balance between the strength of the several components. Materials and their treatment will be chosen. These important objectives can be attained only by analysis based upon the principles ofmechanics, such as those of statics for reaction forces and for the optimumutilization of friction; of dynamics for inertia, acceleration, and energy; of elasticity and strength of materials for stress。
机械类外文文献及翻译大全
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机械外文文献翻译
附录：2原文：Mechanical Technology in the rubber industry outlined in theapplicationIn the development of human society is the modern process. Rubber Industries is an indispensable Economy, Trade and Industry. In the rubber industry in the development of rubber technology and rubber machinery (or electromechanical) to the progress and development of technology played an important role in promoting this. The development of rubber industry, rubber and rubber machinery industry technology constitutes of technical rubber products all the technical process and industrial technology system. In 1820 by the British made the human-driven single-roller rubber mixing machine. 1826 twin-roll Drum open rubber mixing machine into production beginning of the human rubber machinery production prelude. So far, human society has been the application of rubber machinery 180 years of history.Since 1839. A series of rubber machinery and equipment will come out, in addition to the application of vulcanized rubber vulcanization facilities, and other rubber machinery, such as plunger hose extrusion machine (1858), screw extruder (1879), rubber rolling mill (1843 ~ 1900), Closed rubber mixing machine (1916) rubber machinery and equipment. At that time, has spent the rubber industry production process, the promotion of the development of rubber industry has played a facilitating role.1904, lead oxide, magnesium oxide, such as the discovery of inorganic curing agent, in particular 1919 organic to fide D, the discovery and use of M, and further promote the improvement of production efficiency has greatly improved the performance of the use of rubber products, expanded use. 1920 accession the carbon black to rubber, makes rubber products would be an overall improvement in performance and improvement. Therefore, the application of carbon black in rubber is improve the industry and promoting the progress and all-round development. In the early 20th century and the middle of the Soviet Union, the United States, Britain,Germany, France and other countries, has invented a synthetic rubber industrial technologies, and the establishment of a series of synthetic rubber production equipment and factories. Coupled with the region's natural rubber production of large-scale resources for the mankind modern rubber industry opened up the comprehensive development of the material resource base.Is a highly flexible rubber typical materials, its physical properties are very complicated. Most of the processing of rubber molding process are similar to the melt flow and deformation process, but also in the processing of rubber products, the Health and plastic to go through plastic necklace, mixing, pressure-type, shape, curing process procedures, in order to become products. In the modern chemical products, such as rubber, plastics, paints, fibers, lubricants, ceramics, and other similar material production and engineering applications, the complexity of its mechanical properties. Purely based on the elasticity, viscosity or plasticity theory can not meet these materials processing requirements of the deformation process. So based on the nature of the complex mechanics of the research topic - theological theory will be referred to the new human research subjects on the agenda. 1928, the United States set up the "Evolution Society", 1940, the British set up the theological Club (later renamed the Institute of Evolution). In addition, the Netherlands, West Germany, France, Japan and other countries have also set up a corresponding flow Institute. 1948 convene the International Society of Theology. In 1953 the establishment of the International Association of theology is hold. Since then one involving applied mathematics, physics, elasticity, the material mechanics, fluid mechanics, geology, engineering and other subjects on the verge of disciplines - have emerged theology, and gradually has been extensively applied. Theology not only in the rubber, plastics, coatings, printing, Portland, foodstuffs, and other industrial production has been extensively applied, but also to infrastructure, machinery, transport, irrigation, chemical industry and many other industrial sectors: involves many substances from solid to liquid processes. Theology made in the rubber industry. Widely used in the processing of rubber molding products research and application. Such as rubber mixing、rolling、extrusion、injection molding and other processes. Because of its macromolecular polymer chain structure and movement characteristics of the physical state gathered on showing fourkinds of physical state: a crystalline and non-crystalline 3 crystalline (glass state, high-elastic state, viscous flow state).Rubber in normal circumstances is the use of high-elastic state. In the course of processing molding viscous flow state, in the vulcanized only basic treatment before losing mobility, and a high flexibility based elastic material.Because of the late 19th century and early 20th century, the theory of rubber is exploration and the principles of the invention. Especially theology and application of the theoretical study of the development of rubber industry makes, whether in the filler, vulcanization accelerator, or in the process principle aspects have undergone profound changes. On the development of the rubber industry is a qualitative change. At the same time, all kinds of rubber machinery also made great progress and development. At that time, not only the names many rubber machinery, and its structure, specifications, varieties, and so had been reached a certain level of the scale, fine, and the degree of automation and linkage. If rubber mechanical transmission power to hundreds of to thousands of kilowatts stem watts, which weight machines to a few hundred tons. Rubber products in the process of production plastic necklace, mixing, rolling, extrusion, molding, in the process of curing six have a complete matching of mechanical devices.Compound rubber machinery industry is one of the basic equipment. At present production machinery to open dozens of rubber mixing. Health glue used plastic necklace, plastic material mixing; pressed for the compression machine for plastic, decorticating machine compound mainly used for preheating and plastic; crusher for crushing such as natural rubber, remove plastic washing machine for Health and plastic waste compound impurities; mill mainly used for waste plastic block grinding; refining machine used to remove the hard plastic renewable impurities; reclaimed rubber mixing machine, mainly for the reclaimed rubber pinch; breathing machine for plastic pressure breathing Film compression; crepe-pressure machine, mainly for crepe-compression; experimental rubber mixing machine, the main compound used in a small number of experiments, etc. .Rubber rolling mill, which is rubber products processing in the process of one of the basic equipment. Since 1843 three-roll calendar application, we have 160 years ofdevelopment history. From the modern to modern specifications and various new calendar will continue to emerge, its specifications, speed, semi product of high accuracy, a high degree of automation machinery, the machinery has become the modern calendar of the main structural features. At present production largest calendar has reached more than φ1055 × 3000 (mm), roller line speed of up to 120(m / min) above, the semi-finished calendar has reached its thickness error within ±0.0025 (mm). And achieve full electronic control of the computer and automation level.The Closed Compound (mixer), rubber and plastic mixing refining is one of the main equipment. The development of modern mixer, a high-speed, high-pressure and high-performance characteristics, and is divided into low-speed (20 to the rotor speed / min), the velocity (speed of 30 to 40 ~ / min) and high-speed (60 to speed / min) 3. In recent years also appear to speed in the 80 / mixer at high speed over armed Rubber extruder (screw extruder), the world's first since 1879-screw extruder Since the birth of all kinds of screw extruder machinery in a large number of different varieties have been supporting complete specification has been adapted to different product performance characteristics of the request. If pressure extrusion machine, mainly for the shape of the semi-finished production; filter plastic extrusion machine for removing plastic mix and the Health and the impurity; plastic extrusion machine for the continuous plastic glue Health: granulation extruders for plastic compound and the Health and the granulation; compression extruder. To compound the pressure plate; desulfurization renewable plastic extruder for the desulfurization: extrusion dehydration mixing rubber extruder for dehydration and regeneration plastic dry: Cable extruder for the cable coated molding; row Gas extruder. The mixing compound got out of the air and water and volatile compounds, such as low-molecular-weight. These specifications complete extrusion machinery, the development of the rubber industry and was credited. It has become the driving force of the rubber products processing and optimization of the equipment. Injection Molding Machine, also known as the Note Press, mainly for the production of rubber molded products. Note pressure machinery, its structure, is divided into horizontalinjection press, vertical injection press, injection machine and the Multi-Position Press Note 4. Press each note is divided into many different sizes of the specifications.Tire rubber industry is the largest number one product. Whether raw materials from the use of rubber and rubber products, put out of rubber products which occupy the lion's share of the market, consume about 80% of the volume of rubber resources. Therefore, the tire molding machinery is also important. Since the invention of pneumatic tire in 1888, with the development of the automobile industry, various specifications, the various properties of a large number of rubber tires. A high-performance, high-quality car, if there is no corresponding performance and quality of the tire support is equivalent to scrap general. And the development of tire industry tire molding machinery participation is crucial. Tubeless tire or whether they would have to be certain to die molding machinery stereotypes. Forming particular tire, tire production is in the process of core processes, tire various "parts" of the assembly process, will soon cord, bead, wrapper, tread, and other components of processed into paste composition tire embryo. Therefore tire molding machinery determines to a large extent the performance and quality of tires. As human socio-economic and cultural progress and development, a wide range of a large number of vehicles. Therefore the various types and specification is endless. Such as cars, buses, trucks, construction vehicles and other special vehicles and aircraft, which have their own dedicated tire varieties and specifications. In recent years there has high strength and high wear resistance of the steel skeleton radial tire, making automobile tires, performance and the structure and quality to a new level. This constant tire molding machinery put out a higher demand.Tire molding machine many of the types, according to the method of forming: sleeve-law and two kinds of stickers; by shaping the contours of the drum: drum, semi-drum, and the core-wheeled four-wheel-core. In addition, all other uses of different shapes and rubber products, there is a basic molding process. Therefore a variety of rubber molding machines and even offers a dazzling. Only a wide variety of ring is tens of thousands of species on the number. This shows that the rubber molding machinery industry is also very complicated and very important.Vulcanization machinery, a variety of rubber products of the final steps in the processing machinery, mainly for the various rubber products, plastic, rubber products, such as sulfide processing. The main structure of three kinds of forms: one is flat vulcanize, and the autoclave (including pressure autoclave) and the drum machine sulfide. Flat-curing the use of broader is more variety. In addition to direct use of vulcanized rubber products processing, can also be used in the plastics industry thermoplastic or thermosetting plastic plastics processing repression. Because of their body structure and working principle is basically the same. The types and forms are many. According to the purpose, has the vulcanized rubber model of flat products, with flat-curing machine, V-belt plate curing machine, sheet plate curing machine. Vulcanized rubber products tank is the first production application of curing equipment, mainly for the vulcanization of rubber products work. Can also be used to autoclave the curing soles, adhesive tape and model products. Therefore, "omnipotent" said curing machine. Drum curing machine, "belt" and the "V-belt" two categories. Mainly used for curing surface shape and surface quality of the special requirements of thin strip of rubber products, such as tread rubber and plastic sheet printing and dyeing, such as the conduction band. If accompanied by the necessary accessories device can be used to transport sulfide zone, belts and other similar products vulcanized rubber processing. Drum Machine continuous vulcanization sulfide, easy assembly and the formation of automated production lines. Substantially reduce labor intensity and improve efficiency and product quality.For the development of rubber industry, mechanical and process technology research determines its speed and level of development determines the performance and quality of products. Generally speaking, industrial technology research and product cycle faster some frequency. Changes in technology and machinery cycle is slow, it decided to change the cycle of the life of the equipment, work efficiency and product quality. It is precisely because of machinery and equipment has a clear life, it makes the certain inertia of the operation. Thus create a difficult change or do not need rapid changes in the direct experience. This is a reality for many people, the community and even some scientific research and departments only attaches great importance to technology innovation and ignore changes in mechanical andtechnological advances and the development of one of the main reasons. The mindset of the people is to determine awareness of changes and developments. Any material production originated in the first production practice on the real social needs of the objective.or the rubber industry development, which is not only the normal process of production is rubber products. Mechanical technology and the increasing need in-depth study of technology and joint development of modern commodity market competitive situation also not tolerate such people wait wait-and-see or delay time, and in addition to the sustenance of mankind growing material and cultural wealth, the need for rapid development of the rubber industry, large piles of scrap rubber, people also need to face the urgent and effective treatment. This is not only the rubber resources conservation needs, but also the living environment of human security requirements. To solve the normal development of rubber industry and scrap rubber recycling use of resources, only mechanical technology and the joint development of technology to achieve their goals. Contemporary rubber industry development so that the waste rubber recycling of resources must take machines improvement and progress in the joint development of the road is the only correct way. And the improvement of machinery technology is the essence of mechanical work of the progress of chemical process technology is the core content of their joint development of the modern rubber industry is able to quickly and efficiently optimize and promote the development of intrinsic motivation. Of course also includes scientific management technology decision-making body elements.Machinery, physics, chemistry (or chemical), the four basic skills of a development of the human society science technology system, and science and technology system known as compulsory, and social management technology is soft science and technology system. Taken Flex became a more complete scientific and technological system. Rubber industry in the development of rubber industry and technology and scientific management technology industries with the economic structure of the industry is related to the development of rubber industry "carrot and stick" scientific measures. Mechanical Technology is a hard attribute technology, technology is a soft attributes, which is a "carrot and stick" form of the technology.In the mechanical technology of the technical attributes of both tangible and intangible. All of investigation and study, the work of design techniques are soft attributes that in the manufacturing of construction involves the technical attributes of hardware technology, the results of pre-main soft technology embodied in the design and construction drawings and manuals; after a hard stage technical achievements on various material on the output of products. This is a hard and soft technology into the outcome of the objective process. Rubber industrial development, we must attach importance mechanical technology and the joint development of technology. Strengthening the role of rubber machinery technology, mechanical technology to the development and application, the whole social development is not only the production of the material and cultural needs, but also the harmonious development of the ecological environment of human needs, but also to be cherished rubber, Using and frugal behavior needs .译文：机械技术在橡胶工业中的应用概述在人类社会发展的现代进程中．橡胶工业也是一门不可缺少的经济产业。
机械设计英文文献(带翻译)
英语文献翻译Introduction of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the work piece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes aresuitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to.Depth of penetration of a cutting tool -- to inches dollars -- is the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishing, deeper penetration of a cutting tool depth.Rough machining and finishing machiningThere are two kinds of cuts in machine- shop work called, respectively, the "roughing cut" and the "finishing cut". When a piece is "roughed out", it is quite near the shape and size required, but enough metal has been left on the surface to finish smooth and to exact size." Generally speaking, bars of steel, forging, castings, etc. are machined to the required shape and size with only one roughing and one finishing cut. Sometimes, however, certain portions of a piece may require more thanone roughing cut. Also, in some jobs, for example, when great accuracy is not needed, or when a comparatively small amount of metal must be removed, a finishing cut may be all that is required. The roughing cut, to remove the greater part of the excess material, should be reasonably heavy, that is, all the machine, or cutting tool, or work, or all three, will stand. So the machinist’s purpose is to remove the excess stock as fast as he can without leaving, at the same time, a surface too torn and rough, without bending the piece if it is slender, and without spoiling the centers. The finishing cut, to make the work smooth and accurate, is a finer cut. The emphasis here is refinement - very sharp tool, comparatively little metal removed, and a higher degree of accuracy in measurement. Whether roughing or finishing, the machinist must set the machine for the given job. He must consider the size and shape of the work and the kind of material, also the kind of tool used and the nature of the cut to be made, then he proceeds to set the machine for the correct speed and feed and to set the tool to take the depth of cut desired.Automatic Fixture DesignAssembly equipment used in the traditional synchronous fixture put parts of the fixture mobile center, to ensure that components from transmission from the plane or equipment plate placed after removal has been scheduled for position. However, in certain applications, mobile mandatory parts of the center line, it may cause parts or equipmentdamage. When parts vulnerability and may lead to a small vibration abandoned, or when their location is by machine spindle or specific to die, Tolerance again or when the request is a sophisticated, it would rather let the fixture to adapt to the location of parts, and not the contrary. For these tasks, Elyria, Ohio, the company has developed Zaytran a general non-functional data synchronization West category FLEXIBILITY fixture. Fixture because of the interaction and synchronization devices is independent; the synchronous device can use sophisticated equipment to replace the slip without affecting the fixture force. Fixture specification range from 0.2 inches itinerary, 5 pounds clamping force of the six-inch trip, 400-inch clamping force. The characteristics of modern production are becoming smaller and smaller quantities and product specifications biggest changes. Therefore, in the final stages of production, assembly of production, quantity and product design changes appear to be particularly vulnerable. This situation is forcing many companies to make greater efforts to rationalize the extensive reform and the previously mentioned case of assembly automation. Despite flexible fixture behind the rapid development of flexible transport and handling devices, such as backward in the development of industrial robots, it is still expected to increase the flexibility fixture. In fact the important fixture devices -- the production of the devices to strengthen investment on the fixture so that more flexibility in economic support holders.According to their flexibility and fixture can be divided into: special fixture, the fixture combinations, the standard fixture, high flexible fixture. Flexible fixture on different parts of their high adaptability and the few low-cost replacement for the characteristic.Forms can transform the structure of the flexible fixture can be installed with the change of structure components (such as needle cheek plate, Multi-chip components and flake cheek plate), a non-standard work piece gripper or clamping elements (for example: commencement standard with a clamping fixture and mobile components fixture supporting documents), or with ceramic or hardening of the intermediary substances (such as : Mobile particle bed fixture and heat fixture tight fixture). To production, the parts were secured fixture, the need to generate clamping function, its fixture with a few unrelated to the sexual submissive steps.According to the processing was part of that foundation and working characteristics to determine the work piece fixture in the required position, then need to select some stability flat combination, These constitute a stable plane was fixed in the work piece fixture set position on the clamp-profile structure, all balanced and torque, it has also ensured that the work features close to the work piece. Finally, it must be calculated and adjusted, assembly or disassembly be standard fixture components required for the position, so that the work piece firmly by clampingfixture in China. In accordance with this procedure, the outline fixture structure and equipped with the planning and recording process can be automated control.Structural modeling task is to produce some stable flat combination, Thus, these plane of the work pieces clamping force and will fixture stability. According to usual practice, this task can be human-machine dialogue that is almost completely automated way to completion. A man-machine dialogue that is automated fixture structure modeling to determine the merits can be conducted in an organized and planning fixture design reduce the amount of the design, shortening the study period and better distribution of work conditions. In short, can be successfully achieved significantly improve fixture efficiency and effectiveness.Fully prepared to structure programs and the number of material circumstances, the completion of the first successful assembly can save up to 60% of the time.Therefore fixture process modeling agencies is the purpose of the program has appropriate documents.机械加工机械加工是所有制造过程中最普遍使用的而且是最重要的方法。
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Abstract: With a focus on the intake tower of the Yanshan Reservoir, this paper discusses the method of modeling in the 3D CAD software SolidWorks and the interface processing between SolidWorks and the ANSYS code, which decreases the difficulty in modeling complicated models in ANSYS. In view of the function of the birth-death element and secondary development with APDL (ANSYS parametric design language), a simulation analysis of the temperature field and thermal stress during the construction period of the intake tower was conveniently conducted. The results show that the temperature rise is about 29.934 □ over 3 or 4 days. The temperature differences between any two points are less than 24 □. The thermal stress increases with the temperature difference and reaches its maximum of 1.68 MPa at the interface between two concrete layers.Key words: SolidWorks; ANSYS; APDL; birth-death element; temperature field; thermal stress1 IntroductionMass concrete is widely used in civil and hydraulic engineering nowadays, and its thermal stress increasingly attracts attention during design and construction. It is necessary to analyze the temperature field and thermal stress of important mass concrete structures with both routine methods and the finite element method (FEM). Some researchers have done a large amount of simulation analyses using FEM software (Tatro 1985; Barrett et al. 1992; Kawaguchi and Nakane 1996; Zhu and Xu 2001; Zhu 2006), but difficulties in these methods remain. There are two main difficulties: (1) Most mass concrete structures are complex and difficult to model with FEM software. (2) Complete simulation is difficult with FEM software because of the complex construction processes and boundary conditions of concrete. The structure of the intake tower of the Yanshan Reservoir is complex. It is 34.5 m high and there is a square pressure tunnel at the bottom, the side length of which is 6 m. The intake tower was modeled in the 3D CAD software SolidWorks and imported into ANSYS with an interface tool. Then, using the APDL program, analysis of the temperature field and thermal stress during construction was conducted.2 Modeling in SolidWorks and interface processing between SolidWorks and ANSYS 2.1 Modeling in SolidWorksSolidWorks is a CAD/CAE/CAM/PDM desktop system, and the first 3Dmechanical CAD software in Windows developed by the SolidWorks company. It provides product-level automated design tools (Liu and Ren 2005). The outside structure of the intake tower is simple but the internal structure is relatively complex. Therefore, the process of modeling is undertaken from the inside to the outside. The integrated and internal models of the intake tower are shown in Fig. 1 and Fig. 2.图片 Fig. 1 Integrated model Fig. 2 Cross section2.2 Interface processing between SolidWorks and ANSYSANSYS is a type of large universal finite element software that has a powerful ability to calculate and analyze aspects of structure, thermal properties, fluid, electromagnetics, acoustics and so on. In addition, the interface of ANSYS can be used to import the CAD model conveniently (Zhang 2005), which greatly reduces the difficulties of dealing with complex models. The interface tools are given in Table 1.Table 1 CAD software packages and preferred interface tools图表1After modeling in SolidWorks, it is necessary to save the model as a type of Parasolid (*.x_t) so as to import it into ANSYS correctly. Then, in ANSYS, the importing of the model is completed with the command “PARAIN, Name, Extension, Path, Entity, FMT, Scale” or the choice of “FileDImportDPARA...” in the GUI interface. There are two means of importing: selecting or not selecting “Allow Defeaturing”，the differences of which are shown in Fig. 3 and Fig. 4.图片Fig. 3 Importing with defeaturing Fig. 4 Importing without defeaturing3 Analysis of temperature field of intake towerThe temperature analysis of the intake tower during the construction period involves aspects of the temperature field and thermal stress. The calculation must deal with the problems of simulation of layered construction, dynamic boundary conditions, hydration heat, dynamic elasticity modulus, autogenous volume deformation of concrete and thermal creep stress, which are difficult to simulate directly in ANSYS. APDL is a scripting language based on the style of parametric variables. It is used to reduce a large amount of repetitive work in analysis (Gong and Xie 2004). This studycarried out a simulation analysis of the temperature field considering nearly all conditions of construction, using the birth-death element and programming with APDL.3.1 Solving temperature field principle3.1.1Unsteady temperature field analysisThe temperature of concrete changes during the construction period due to the effect of hydration heat of cement. This problem can be expressed as a heat conduction problem with internal heat sources in the area. The unsteady temperature field T(x, y, z,D ) is written as (Zhu 1999):公式1where □ is the thermal conductivity of concrete, c is the specific heat of concrete, □ is the density of concrete, □ is the adiabatic temperature rise of concrete, and □ is the age of concrete.In the 3D unsteady temperature field analysis, the functional form I e (T) is 公式2where □R is a subfield of unit e ; □0 is the area on surface D , which is only in boundary units; c□□□□; □ is the exothermic coefficient; the thermal diffusivityc□□□□ ; and isthe air temperature.a T3.1.2Initial conditions and boundary conditions of concrete The initial conditions are the distribution laws of the initial transient temperature of internal concrete. The calculated initial temperature of concrete is 10 □.The index formula of hydration heat of cement is公式3where t is the pouring time. The conversion between Q and □ is 公式4The boundary conditions involve the laws of interaction between concrete and the surrounding medium. When concrete is exposed to the air, the boundary conditionis 公式5where n is the normal direction. Both and a T □ are constants or variables (Ashida and Tauchert 1998; Lin and Cheng 1997). During the maintenance period, the insulation materials of concrete are steel formworks and straws, and the exothermic coefficient of the outer surface is reduced as equivalent processing. The exothermic coefficients of the steel formwork and the straw are 45 kJ/(m2h+0) and 10 kJ/(m2h+0)，respectively. Based on the local temperature during construction, the following formula can be fitted according to the temperature variation curve:公式63.2 Analysis of temperature field in ANSYSThe simulation scheme of layered construction, which is based on the real construction scheme, is shown in Table 2. The pouring days in Table 2 are all the total days of construction for each layer. A layer is not poured until the former layer is poured.图表2The feature points are selected in every layer above the base plate. The maximum temperatures and the temperature curves are given in Table 3 and Fig. 5, respectively.Table 3 Coordinates and maximum temperature of feature points图表3 图片5Fig. 5 Maximum temperature curvesFig. 5 shows that the maximum temperature of each layer occurs on the 3rd or 4th day after pouring, and then the temperature decreases with time, which is consistent with related literature (Lin and Cheng 1997; Luna and Wu 2000; Wu and Luna 2001). In Fig. 5, the numbers of feature points from 2 to 8 are corresponding to their maximum temperature curves from Nodetemp 2 to Nodetemp 8, and the curve of Nodetemp 9 is the air temperature curve. Feature point 8, the maximum temperature of which is 29.934 □ , occurring on the 206th day of the total construction period, shows the maximumtemperature rise during the construction period. Feature point 4, the coordinates of which are (16.4, 16.0, 5.0), shows the maximum temperature difference of 23.5340.4 Analysis of thermal stress of intake towerExpansion or contraction of the structure occurs during heating and cooling. If the expansion or contraction of different parts is inconsistent, then thermal stress occurs. The indirect method was adopted in this study: the temperature of nodes was first obtained in analysis of the temperature field, and then applied to the structure as a body load.4.1 Selection of calculating parametersThe parameters of concrete are given in Table 4.The elasticity modulus is公式7Table 4 Parameters of concrete图表4The creep effect must be considered in analysis of temperature stress. The creep degree of concrete is influenced by the cement type, water-cement ratio and admixture. The formula of the creep degree is 公式8Considering the creep degree, the formula of the elasticity modulus is adjusted to be公式94.2 Analysis of thermal stress in ANSYSAs in analysis of the temperature field, feature points were selected in each layer above the base plate, and their coordinates were the same as those in the temperature field analysis. The maximum thermal stress of each point is shown in Table 5. Feature point 9, the coordinates of which are (17.4, 10.8, 8.0), is the point with the maximum thermal stress.Table 5 Maximum thermal stress of feature points图表5The thermal stress curves of feature points are shown in Fig. 6.图片6Fig. 6 Maximum stress curvesIn Fig. 6, the numbers of feature points from 2 to 9 are corresponding to their maximum stress curves from S1_2 to S1_9, and the S1_10 curve is the ultimate tensile stress of concrete. The formula of concrete’s ultimate tensile stress is公式10The figures and table show that the maximum thermal stress of the intake tower is 1.68 MPa, occurring on the 90th day of the construction period, which is the end of the third layer maintenance period and the beginning of the pouring of the fourth layer. It is known that the thermal stress increases with the temperature difference. Feature point 9 is located at the interface between the third layer and the fourth layer. Thus, it is postulated that the maximum thermal stress is caused by the instantaneous temperature difference between two layers in the pouring period. In Fig. 6, the S1_10 curve shows the ultimate tensile stress curve of concrete. It is known that the maximum thermal stress of each point in the intake tower during the constructionperiod is less than the ultimate tensile stress of concrete.5 Conclusions⑴ The problem of the interface between SolidWorks and ANSYS is resolved in this study, realizing an effective combination of the advantages of both SolidWorks and ANSYS and providing a basis for analysis in ANSYS.(2)Using a birth-death element and considering layered construction, dynamic boundary conditions, hydration heat, the dynamic elasticity modulus, autogenous volume deformation and creep of concrete, the temperature field and thermal stress during the construction period are conveniently obtained due to the virtues of secondary development with APDL.(3)The analysis of temperature shows that the temperature of concrete rises rapidly in the early stage of construction, reaches a maximum value of 29.934 □ on the 3rd or 4th day after pouring, drops thereafter, and is consistent with air temperature after about 30 days. The thermal stress increases with the temperature difference, and the occurrence time of the maximum thermal stress is consistent with that of the maximum temperature difference. The maximum thermal stress occurs at the interface of new and old layers and is caused by the instantaneous temperature difference, the value of whichis 1.68 MPa.(4)The maximum thermal stress is less than the ultimate tensile stress of concrete, which illustrates that the curing measures in construction are effective. Meanwhile, in view of the fact that the maximum thermal stress occurs at the interface of new and old layers, more attention should be paid to it, especially when there is a long interval of time between the pouring of different layers.ReferencesAshida, F., and Tauchert, T. R. 1998. An inverse problem for determination of transient surface temperature from piezoelectric sensor measurement. Journal of Applied Mechanics, 65(2), 367-373. [doi:10.1115/1.2789064]Barrett, P. R., Foadian, H., James, R. 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