钢结构毕业设计论文(中英)
毕业设计的论文中英翻译
Anti-Aircraft Fire Control and the Development of IntegratedSystems at SperryT he dawn of the electrical age brought new types of control systems. Able to transmit data between distributed components and effect action at a distance, these systems employed feedback devices as well as human beings to close control loops at every level. By the time theories of feedback and stability began to become practical for engineers in the 1930s a tradition of remote and automatic control engineering had developed that built distributed control systems with centralized information processors. These two strands of technology, control theory and control systems, came together to produce the large-scale integrated systems typical of World War II and after.Elmer Ambrose Sperry (I860-1930) and the company he founded, the Sperry Gyroscope Company, led the engineering of control systems between 1910 and 1940. Sperry and his engineers built distributed data transmission systems that laid the foundations of today‟s command and control systems. Sperry‟s fire control systems included more than governors or stabilizers; they consisted of distributed sensors, data transmitters, central processors, and outputs that drove machinery. This article tells the story of Sperry‟s involvement in anti-aircraft fire control between the world wars and shows how an industrial firm conceived of control systems before the common use of control theory. In the 1930s the task of fire control became progressively more automated, as Sperry engineers gradually replaced human operators with automatic devices. Feedback, human interface, and system integration posed challenging problems for fire control engineers during this period. By the end of the decade these problems would become critical as the country struggled to build up its technology to meet the demands of an impending war.Anti-Aircraft Artillery Fire ControlBefore World War I, developments in ship design, guns, and armor drove the need for improved fire control on Navy ships. By 1920, similar forces were at work in the air: wartime experiences and postwar developments in aerial bombing created the need for sophisticated fire control for anti-aircraft artillery. Shooting an airplane out of the sky is essentially a problem of “leading” the target. As aircraft developed rapidly in the twenties, their increased speed and altitude rapidly pushed the task of computing the lead out of the range of human reaction and calculation. Fire control equipment for anti-aircraft guns was a means of technologically aiding human operators to accomplish a task beyond their natural capabilities.During the first world war, anti-aircraft fire control had undergone some preliminary development. Elmer Sperry, as chairman of the Aviation Committee of the Naval Consulting Board, developed two instruments for this problem: a goniometer,a range-finder, and a pretelemeter, a fire director or calculator. Neither, however, was widely used in the field.When the war ended in I918 the Army undertook virtually no new development in anti-aircraft fire control for five to seven years. In the mid-1920s however, the Army began to develop individual components for anti-aircraft equipment including stereoscopic height-finders, searchlights, and sound location equipment. The Sperry Company was involved in the latter two efforts. About this time Maj. Thomas Wilson, at the Frankford Arsenal in Philadelphia, began developing a central computer for firecontrol data, loosely based on the system of “director firing” that had developed in naval gunn ery. Wilson‟s device resembled earlier fire control calculators, accepting data as input from sensing components, performing calculations to predict the future location of the target, and producing direction information to the guns.Integration and Data TransmissionStill, the components of an anti-aircraft battery remained independent, tied together only by telephone. As Preston R. Bassett, chief engineer and later president of the Sperry Company, recalled, “no sooner, however, did the components get to the point of functioning satisfactorily within themselves, than the problem of properly transmitting the information from one to the other came to be of prime importance.”Tactical and terrain considerations often required that different fire control elements be separated by up to several hundred feet. Observers telephoned their data to an officer, who manually entered it into the central computer, read off the results, and telephoned them to the gun installations. This communication system introduced both a time delay and the opportunity for error. The components needed tighter integration, and such a system required automatic data communications.In the 1920s the Sperry Gyroscope Company led the field in data communications. Its experience came from Elmer Spe rry‟s most successful invention, a true-north seeking gyro for ships. A significant feature of the Sperry Gyrocompass was its ability to transmit heading data from a single central gyro to repeaters located at a number of locations around the ship. The repeaters, essentially follow-up servos, connected to another follow-up, which tracked the motion of the gyro without interference. These data transmitters had attracted the interest of the Navy, which needed a stable heading reference and a system of data communication for its own fire control problems. In 1916, Sperry built a fire control system for the Navy which, although it placed minimal emphasis on automatic computing, was a sophisticated distributed data system. By 1920 Sperry had installed these systems on a number of US. battleships.Because of the Sperry Company‟s experience with fire control in the Navy, as well as Elmer Sperry‟s earlier work with the goniometer and the pretelemeter, the Army approached the company for help with data transmission for anti-aircraft fire control. To Elmer Sperry, it looked like an easy problem: the calculations resembled those in a naval application, but the physical platform, unlike a ship at sea, anchored to the ground. Sperry engineers visited Wilson at the Frankford Arsenal in 1925, and Elmer Sperry followed up with a letter expressing his interest in working on the problem. He stressed his company‟s experience with naval problems, as well as its recent developments in bombsights, “work from the other end of the pro position.” Bombsights had to incorporate numerous parameters of wind, groundspeed, airspeed, and ballistics, so an anti-aircraft gun director was in some ways a reciprocal bombsight . In fact, part of the reason anti-aircraft fire control equipment worked at all was that it assumed attacking bombers had to fly straight and level to line up their bombsights. Elmer Sperry‟s interests were warmly received, and in I925 and 1926 the Sperry Company built two data transmission systems for the Army‟s gun directors.The original director built at Frankford was designated T-1, or the “Wilson Director.” The Army had purchased a Vickers director manufactured in England, but encouraged Wilson to design one thatcould be manufactured in this country Sperry‟s two data tran smission projects were to add automatic communications between the elements of both the Wilson and the Vickers systems (Vickers would eventually incorporate the Sperry system into its product). Wilson died in 1927, and the Sperry Company took over the entire director development from the Frankford Arsenal with a contract to build and deliver a director incorporating the best features of both the Wilson and Vickers systems. From 1927 to 193.5, Sperry undertook a small but intensive development program in anti-aircraft systems. The company financed its engineering internally, selling directors in small quantities to the Army, mostly for evaluation, for only the actual cost of production [S]. Of the nearly 10 models Sperry developed during this period, it never sold more than 12 of any model; the average order was five. The Sperry Company offset some development costs by sales to foreign govemments, especially Russia, with the Army‟s approval 191.The T-6 DirectorSperry‟s modified version of Wilson‟s director was designated T-4 in development. This model incorporated corrections for air density, super-elevation, and wind. Assembled and tested at Frankford in the fall of 1928, it had problems with backlash and reliability in its predicting mechanisms. Still, the Army found the T-4 promising and after testing returned it to Sperry for modification. The company changed the design for simpler manufacture, eliminated two operators, and improved reliability. In 1930 Sperry returned with the T-6, which tested successfully. By the end of 1931, the Army had ordered 12 of the units. The T-6 was standardized by the Army as the M-2 director.Since the T-6 was the first anti-aircraft director to be put into production, as well as the first one the Army formally procured, it is instructive to examine its operation in detail. A technical memorandum dated 1930 explained the theory behind the T-6 calculations and how the equations were solved by the system. Although this publication lists no author, it probably was written by Earl W. Chafee, Sperry‟s director of fire control engineering. The director was a complex mechanical analog computer that connected four three-inch anti-aircraft guns and an altitude finder into an integratedsystem (see Fig. 1). Just as with Sperry‟s naval fire control system, the primary means of connection were “data transmitters,” similar to those that connected gyrocompasses to repeaters aboard ship.The director takes three primary inputs. Target altitude comes from a stereoscopic range finder. This device has two telescopes separated by a baseline of 12 feet; a single operator adjusts the angle between them to bring the two images into coincidence. Slant range, or the raw target distance, is then corrected to derive its altitude component. Two additional operators, each with a separate telescope, track the target, one for azimuth and one for elevation. Each sighting device has a data transmitter that measures angle or range and sends it to the computer. The computer receives these data and incorporates manual adjustments for wind velocity, wind direction, muzzle velocity, air density, and other factors. The computer calculates three variables: azimuth, elevation, and a setting for the fuze. The latter, manually set before loading, determines the time after firing at which the shell will explode. Shells are not intended to hit the target plane directly but rather to explode near it, scattering fragments to destroy it.The director performs two major calculations. First, pvediction models the motion of the target and extrapolates its position to some time in the future. Prediction corresponds to “leading” the target. Second, the ballistic calculation figures how to make the shell arrive at the desired point in space at the future time and explode, solving for the azimuth and elevation of the gun and the setting on the fuze. This calculation corresponds to the traditional artillery man‟s task of looking up data in a precalculated “firing table” and setting gun parameters accordingly. Ballistic calculation is simpler than prediction, so we will examine it first.The T-6 director solves the ballistic problem by directly mechanizing the traditional method, employing a “mechanical firing table.” Traditional firing tables printed on paper show solutions for a given angular height of the target, for a given horizontal range, and a number of other variables. The T-6 replaces the firing table with a Sperry ballistic cam.” A three-dimensionally machined cone shaped device, the ballistic cam or “pin follower” solves a pre-determined function. Two independent variables are input by the angular rotation of the cam and the longitudinal position of a pin that rests on top of the cam. As the pin moves up and down the length of the cam, and as the cam rotates, the height of the pin traces a function of two variables: the solution to the ballistics problem (or part of it). The T-6 director incorporates eight ballistic cams, each solving for a different component of the computation including superelevation, time of flight, wind correction, muzzle velocity. air density correction. Ballistic cams represented, in essence, the stored data of the mechanical computer. Later directors could be adapted to different guns simply by replacing the ballistic cams with a new set, machined according to different firing tables. The ballistic cams comprised a central component of Sperry‟s mechanical computing technology. The difficulty of their manufacture would prove a major limitation on the usefulness of Sperry directors.The T-6 director performed its other computational function, prediction, in an innovative way as well. Though the target came into the system in polar coordinates (azimuth, elevation, and range), targets usually flew a constant trajectory (it was assumed) in rectangular coordinates-i.e. straight andlevel. Thus, it was simpler to extrapolate to the future in rectangular coordinates than in the polar system. So the Sperry director projected the movement of the target onto a horizontal plane, derived the velocity from changes in position, added a fixed time multiplied by the velocity to determine a future position, and then converted the solution back into polar coordinates. This method became known as the “plan prediction method”because of the representation of the data on a flat “plan” as viewed from above; it was commonly used through World War II. In the plan prediction method, “the actual movement of the target is mechanically reproduced on a small scale within the Computer and the desired angles or speeds can be measured directly from the movements of these elements.”Together, the ballistic and prediction calculations form a feedback loop. Operators enter an estimated “time of flight” for the shell when they first begin tracking. The predictor uses this estimate to perform its initial calculation, which feeds into the ballistic stage. The output of the ballistics calculation then feeds back an updated time-of-flight estimate, which the predictor uses to refine the initial estimate. Thus “a cumulative cycle of correction brings the predicted future position of the target up to the point indicated by the actual future time of flight.”A square box about four feet on each side (see Fig. 2) the T-6 director was mounted on a pedestal on which it could rotate. Three crew would sit on seats and one or two would stand on a step mounted to the machine. The remainder of the crew stood on a fixed platform; they would have had to shuffle around as the unit rotated. This was probably not a problem, as the rotation angles were small. The direc tor‟s pedestal mounted on a trailer, on which data transmission cables and the range finder could be packed for transportation.We have seen that the T-6 computer took only three inputs, elevation, azimuth, and altitude (range), and yet it required nine operators. These nine did not include the operation of the range finder, which was considered a separate instrument, but only those operating the director itself. What did these nine men do?Human ServomechanismsTo the designers of the director, the operato rs functioned as “manual servomechanisms.”One specification for the machine required “minimum dependence on …human element.‟ The Sperry Company explained, “All operations must be made as mechanical and foolproof as possible; training requirements must visualize the conditions existent under rapid mobilization.” The lessons of World War I ring in this statement; even at the height of isolationism, with the country sliding into depression, design engineers understood the difficulty of raising large numbers of trained personnel in a national emergency. The designers not only thought the system should account for minimal training and high personnel turnover, they also considered the ability of operators to perform their duties under the stress of battle. Thus, nearly all the work for the crew was in a “follow-the-pointer”mode: each man concentrated on an instrument with two indicating dials, one the actual and one the desired value for a particular parameter. With a hand crank, he adjusted the parameter to match the two dials.Still, it seems curious that the T-6 director required so many men to perform this follow-the-pointer input. When the external rangefinder transmitted its data to the computer, it appeared on a dial and an operator had to follow the pointer to actually input the data into the computing mechanism. The machine did not explicitly calculate velocities. Rather, two operators (one for X and one for Y) adjusted variable-speed drives until their rate dials matched that of a constant-speed motor. When the prediction computation was complete, an operator had to feed the result into the ballistic calculation mechanism. Finally, when the entire calculation cycle was completed, another operator had to follow the pointer to transmit azimuth to the gun crew, who in turn had to match the train and elevation of the gun to the pointer indications.Human operators were the means of connecting “individual elements” into an integrated system. In one sense the men were impedance amplifiers, and hence quite similar to servomechanisms in other mechanical calculators of the time, especially Vannevar Bush‟s differential analyzer .The term “manual servomechanism”itself is an oxymoron: by the conventional definition, all servomechanisms are automatic. The very use of the term acknowledges the existence of an automatic technology that will eventually replace the manual method. With the T-6, this process was already underway. Though the director required nine operators, it had already eliminated two from the previous generation T-4. Servos replaced the operator who fed back superelevation data and the one who transmitted the fuze setting. Furthermore, in this early machine one man corresponded to one variable, and the machine‟s requirement for operators corresponded directly to the data flow of its computation. Thus the crew that operated the T-6 director was an exact reflection of the algorithm inside it.Why, then, were only two of the variables automated? This partial, almost hesitating automation indicates there was more to the human servo-motors than Sperry wanted to acknowledge. As much as the company touted “their duties are purely mechanical and little skill or judgment is required on the part of the operators,” men were still required to exercise some judgment, even if unconsciously. The data were noisy, and even an unskilled human eye could eliminate complications due to erroneous or corrupted data. The mechanisms themselves were rather delicate and erroneous input data, especially if it indicated conditions that were not physically possible, could lock up or damage the mechanisms. Theoperators performed as integrators in both senses of the term: they integrated different elements into a system.Later Sperry DirectorsWhen Elmer Sperry died in 1930, his engineers were at work on a newer generation director, the T-8. This machine was intended to be lighter and more portable than earlier models, as well as less expensive and “procurable in quantities in case of emergency.” The company still emphasized the need for unskilled men to operate the system in wartime, and their role as system integrators. The operators were “mechanical links in the apparatus, thereby making it possible to avoid mechanical complication which would be involved by the use of electrical or mechanical servo motors.” Still, army field experience with the T-6 had shown that servo-motors were a viable way to reduce the number of operators and improve reliability, so the requirements for the T-8 specified that wherever possible “electrical shall be used to reduce the number of operators to a minimum.” Thus the T-8 continued the process of automating fire control, and reduced the number of operators to four. Two men followed the target with telescopes, and only two were required for follow-the-pointer functions. The other follow-the-pointers had been replaced by follow-up servos fitted with magnetic brakes to eliminate hunting. Several experimental versions of the T-8 were built, and it was standardized by the Army as the M3 in 1934.Throughout the remain der of the …30s Sperry and the army fine-tuned the director system in the M3. Succeeding M3 models automated further, replacing the follow-the-pointers for target velocity with a velocity follow-up which employed a ball-and-disc integrator. The M4 series, standardized in 1939, was similar to the M3 but abandoned the constant altitude assumption and added an altitude predictor for gliding targets. The M7, standardized in 1941, was essentially similar to the M4 but added full power control to the guns for automatic pointing in elevation and azimuth. These later systems had eliminated errors. Automatic setters and loaders did not improve the situation because of reliability problems. At the start of World War II, the M7 was the primary anti-aircraft director available to the army.The M7 was a highly developed and integrated system, optimized for reliability and ease of operation and maintenance. As a mechanical computer, it was an elegant, if intricate, device, weighing 850 pounds and including about 11,000 parts. The design of the M7 capitalized on the strength of the Sperry Company: manufacturing of precision mechanisms, especially ballistic cams. By the time the U.S. entered the second world war, however, these capabilities were a scarce resource, especially for high volumes. Production of the M7 by Sperry and Ford Motor Company as subcontractor was a “real choke” and could not keep up with production of the 90mm guns, well into 1942. The army had also adopted an English system, known as the “Kerrison Director” or M5, which was less accurate than the M7 but easier to manufacture. Sperry redesigned the M5 for high-volume production in 1940, but passed in 1941.Conclusion: Human Beings as System IntegratorsThe Sperry directors we have examined here were transitional, experimental systems. Exactly for that reason, however, they allow us to peer inside the process of automation, to examine the displacement of human operators by servomechanisms while the process was still underway. Skilled asthe Sperry Company was at data transmission, it only gradually became comfortable with the automatic communication of data between subsystems. Sperry could brag about the low skill levels required of the operators of the machine, but in 1930 it was unwilling to remove them completely from the process. Men were the glue that held integrated systems together.As products, the Sperry Company‟s anti-aircraft gun directors were only partially successful. Still, we should judge a technological development program not only by the machines it produces but also by the knowledge it creates, and by how that knowledge contributes to future advances. Sperry‟s anti-aircraft directors of the 1930s were early examples of distributed control systems, technology that would assume critical importance in the following decades with the development of radar and digital computers. When building the more complex systems of later years, engineers at Bell Labs, MIT, and elsewhere would incorporate and build on the Sperry Company‟s experience,grappling with the engineering difficulties of feedback, control, and the augmentation of human capabilities by technological systems.在斯佩里防空炮火控和集成系统的发展电气时代的到来带来了新类型的控制系统。
结构稳定理论之钢结构设计论文英文版
Graduate Course Work Steel Structure Stability DesignSchool: China University of MiningName: Liu FeiStudent ID: TSP130604088Grade: 2013Finish Date: 2014.1.1AbstractSteel structure has advantages of light weight, high strength and high degree of industryali zation, which has been widely used in the construction engineering. We often hear this the accident case caused by its instability and failure of structure of casualties and property losses, and the cause of the failure is usually caused by structure design flaws. This paper says the experiences in the design of stability of steel structure through the summary of the stability of steel structure design of the concept, principle, analysis method and combination with engineering practice.Key words:steel structure; stability design; detail structureSteel Structure Stability DesignStructurally stable systems were introduced by Aleksandr Andronov and Lev Pontryagin in 1937 under the name "systèmes grossières", or rough systems. They announced a characterization of rough systems in the plane, the Andronov–Pontryagin criterion. In this case, structurally stable systems are typical, they form an open dense set in the space of all systems endowed with appropriate topology. In higher dimensions, this is no longer true, indicating that typical dynamics can be very complex (cf strange attractor). An important class of structurally stable systems in arbitrary dimensions is given by Anosov diffeomorphisms and flows.In mathematics, structural stability is a fundamental property of a dynamical system which means that the qualitative behavior of the trajectories is unaffected by C1-small perturbations. Examples of such qualitative properties are numbers of fixed points and periodic orbits (but not their periods). Unlike Lyapunov stability, which considers perturbations of initial conditions for a fixed system, structural stability deals with perturbations of the system itself. Variants of this notion apply to systems of ordinary differential equations, vector fields on smooth manifolds and flows generated by them, and diffeomorphisms.The stability is one of the content which needs to be addressed in the design of steel structure engineering. Three are more engineering accident case due to the steel structure instability in the real life. For example,the stadium, in the city of Hartford 92 m by 110 m to the plane of space truss structure, suddenly fell on the ground in 1978. The reason is the compressive bar buckling instability;13.2 m by 18.0 m steel truss, in 1988,lack of stability of the web member collapsed in construction process in China;On January 3, 2010 in the afternoon, 38 m steel structure bridge in Kunming New across suddenly collapsed, killing seven people, 8 people seriously injured, 26 people slightly injured.The reason is that the bridge steel structure supporting system is out of stability, suddenly a bridge collapsing down to 8 m tall. We can see from the above case, the usual cause of instability and failure of steel structure is the unreasonable structural design, structural design defects.To fundamentally prevent such accidents, stability of steel structure design is the key.Structural stability of the system provides a justification for applying the qualitative theory of dynamical systems to analysis of concrete physical systems. The idea of such qualitative analysis goes back to the work of Henri Poincaré on the three-body problem in celestial mechanics. Around the same time, Aleksandr Lyapunov rigorously investigated stability of small perturbations of an individual system. In practice, the evolution law of the system (i.e. the differential equations) is neverknown exactly, due to the presence of various small interactions. It is, therefore, crucial to know that basic features of the dynamics are the same for any small perturbation of the "model" system, whose evolution is governed by a certain known physical law. Qualitative analysis was further developed by George Birkhoff in the 1920s, but was first formalized with introduction of the concept of rough system by Andronov and Pontryagin in 1937. This was immediately applied to analysis of physical systems with oscillations by Andronov, Witt, and Khaikin. The term "structural stability" is due to Solomon Lefschetz, who oversaw translation of their monograph into English. Ideas of structural stability were taken up by Stephen Smale and his school in the 1960s in the context of hyperbolic dynamics. Earlier, Marston Morse and Hassler Whitney initiated and René Thom developed a parallel theory of stability for differentiable maps, which forms a key part of singularity theory. Thom envisaged applications of this theory to biological systems. Both Smale and Thom worked in direct contact with Maurício Peixoto, who developed Peixoto's theorem in the late 1950's.When Smale started to develop the theory of hyperbolic dynamical systems, he hoped that structurally stable systems would be "typical". This would have been consistent with the situation in low dimensions: dimension two for flows and dimension one for diffeomorphisms. However, he soon found examples of vector fields on higher-dimensional manifolds that cannot be made structurally stable by an arbitrarily small perturbation (such examples have been later constructed on manifolds of dimension three). This means that in higher dimensions, structurally stable systems are not dense. In addition, a structurally stable system may have transversal homoclinic trajectories of hyperbolic saddle closed orbits and infinitely many periodic orbits, even though the phase space is compact. The closest higher-dimensional analogue of structurally stable systems considered by Andronov and Pontryagin is given by the Morse–Smale systems.Structure theory of stability study was conducted on the mathematical model of the ideal, and the actual structure is not as ideal as mathematical model, in fact ,we need to consider the influence of various factors. For example ,for the compressive rods, load could not have absolute alignment section center; There will always be some initial bending bar itself, the so-called "geometric defects"; Material itself inevitably has some kind of "defect", such as the discreteness of yield stress and bar manufacturing methods caused by the residual stress, etc. So, in addition to the modulus of elasticity and geometry size of bar, all the above-mentioned factors affecting the bearing capacity of the push rod in different degrees, in the structure design of this influence often should be considered. Usually will be based on the ideal mathematical model to study the stability of thetheory is called buckling theory, based on the actual bar study consider the various factors related to the stability of the stability of the ultimate bearing capacity theory called the theory ofcrushing.Practical bar, component or structure damage occurred during use or as the loading test of the buckling load is called crushing load and ultimate bearing capacity. For simplicity, commonly used buckling load. About geometric defects, according to a large number of experimental results, it is generally believed to assume a meniscus curve and its vector degrees for the rod length of 1/1000. About tissue defects, in the national standard formula is not the same, allow the buckling stress curve given by the very different also, some problems remain to be further research.1.Steel structure stability design concept1.1.The difference between intensity and stabilityThe intensity refers to that the structure or a single component maximum stress (or internal force)caused by load in stable equilibrium state is more than the ultimate strength of building materials, so it is a question of the stress. The ultimate strength value is different according to the characteristics of the material varies. for steel ,it is the yield point. The research of stability is mainly is to find the external load and structure unstable equilibrium between internal resistance. That is to say, deformation began to rapid growth and we should try to avoid the structure entering the state, so it is a question of deformation. For example, for an axial compression columns, in the condition column instability, the lateral deflection of the column add a lot of additional bending moment, thus the fracture load of pillars can be far less than its axial compression strength. At this point, the instability is the main reason of the pillar fracture .1.2.The classification of the steel structure instability1)The stability problem with the equilibrium bifurcation(Branch point instability).2)The axial compression buckling of the perfect straight rod and tablet compression bucklingall belong to this category.3)The stability of the equilibrium bifurcation problem(Extreme value point instability).4)The ability of the loss of stability of eccentric compression member made of constructionsteel in plastic development to a certain degree , fall into this category.5)Jumping instability6)Jumping instability is a kind of different from the above two types of stability problem. Itis a jump to another stable equilibrium state after loss of stability balance.2.The principle of steel structure stability design2.1.For the steel structure arrangement, the whole system and the stability of the part requirements must be considered ,and most of the current steel structure is designed according to plane system, such as truss and frame. The overall layout of structure can guarantee that the flat structure does not appear out-of-plane instability,such as increasing the necessary supporting artifacts, etc. A planar structures of plane stability calculation is consistent with the structure arrangement.2.2.Structure calculation diagram should be consistent with a diagram of a practical calculation method is based on. When designing a single layer or multilayer frame structure, we usually do not make analysis of the framework stability but the frame column stability calculation. When we use this method to calculate the column frame column stability , the length factor should be concluded through the framework of the overall stability analysis which results in the equivalent between frame column stability calculation and stability calculation. For a single layer or multilayer framework, the column length coefficient of computation presented by Specification for design of steel structures (GB50017-2003) base on five basic assumptions. Including:all the pillars in the framework is the loss of stability at the same time, that is ,the critical load of the column reach at the same time. According to this assumes, each column stability parameters of the frame and bar stability calculation method, is based on some simplified assumptions or typical.Designers need to make sure that the design of structure must be in accordance with these assumptions.2.3.The detail structure design of steel structure and the stable calculation of component should be consistent. The guarantee that the steel structure detail structure design and component conforms to the stability of the calculation is a problem that needs high attention in the design of steel structure.Bending moment tonon-transmission bending moment node connection should be assigned to their enough rigidity and the flexibility.Truss node should minimize the rods' bias.But, when it comes to stability, a structure often have different in strength or special consideration. But requirement above in solving the beam overall stability is not enough.Bearing need to stop beam around the longitudinal axis to reverse,meanwhile allowing the beam in thein-plane rotation and free warp beam end section to conform to the stability analysis of boundary conditions. 3.The analysis method of the steel structure stabilitySteel structure stability analysis is directed at the outer loads under conditions of the deformation of structure.The deformation should be relative to unstability deformation of the structure or buckling. Deformation between load and structure is nonlinear relationship , which belongs to nonlinear geometric stability calculation and uses a second order analysis method. Stability calculated, both buckling load and ultimate load, can be regarded as the calculation of the stability bearing capacity of the structure or component.In the elastic stability theory, the calculation method of critical force can be mainly divided into two kinds of static method and energy method.3.1.Static methodStatic method, both buckling load and ultimate load, can be regarded as the calculation of the stability bearing capacity of the structure or component. Follow the basic assumptions in establishing balance differential equation:1)Components such as cross section is a straight rod.2)Pressure function is always along the original axis component3)Material is in accordance with hooke's law, namely the linear relationship between thestress and strain.4)Component accords with flat section assumption, namely the component deformation infront of the flat cross-section is still flat section after deformation.5)Component of the bending deformation is small ant the curvature can be approximatelyrepresented by the second derivative of the deflection function.Based on the above assumptions, we can balance differential equation,substitude into the corresponding boundary conditions and solve both ends hinged the critical load of axial compression component .3.2.Energy methodEnergy method is an approximate method for solving stability bearing capacity, through the principle of conservation of energy and potential energy in principle to solve the critical load values.1)The principle of conservation of energy to solve the critical loadWhen conservative system is in equilibrium state, the strain energy storaged in the structure is equal to the work that the external force do, namely, the principle of conservation of energy. As thecritical state of energy relations:ΔU =ΔWΔU—The increment of strain energyΔW—The increment of work forceBalance differential equation can be established by the principle of conservation of energy.2)The principle of potential energy in value to solve the critical load valueThe principle of potential energy in value refers to: For the structure by external force, when there are small displacement but the total potential energy remains unchanged,that is, the total potential energy with in value, the structure is in a state of balance. The expression is:dΠ=dU-dW =0dU—The change of the structure strain energy caused by virtual displacement , it is always positive;dW—The work the external force do on the virtual displacement;3.3.Power dynamics methodMany parts of the qualitative theory of differential equations and dynamical systems deal with asymptotic properties of solutions and the trajectories—what happens with the system after a long period of time. The simplest kind of behavior is exhibited by equilibrium points, or fixed points, and by periodic orbits. If a particular orbit is well understood, it is natural to ask next whether a small change in the initial condition will lead to similar behavior. Stability theory addresses the following questions: will a nearby orbit indefinitely stay close to a given orbit? will it converge to the given orbit (this is a stronger property)? In the former case, the orbit is called stable and in the latter case, asymptotically stable, or attracting. Stability means that the trajectories do not change too much under small perturbations. The opposite situation, where a nearby orbit is getting repelled from the given orbit, is also of interest. In general, perturbing the initial state in some directions results in the trajectory asymptotically approaching the given one and in other directions to the trajectory getting away from it. There may also be directions for which the behavior of the perturbed orbit is more complicated (neither converging nor escaping completely), and then stability theory does not give sufficient information about the dynamics.One of the key ideas in stability theory is that the qualitative behavior of an orbit under perturbations can be analyzed using the linearization of the system near the orbit. In particular, at each equilibrium of a smooth dynamical system with an n-dimensional phase space, there is acertain n×n matrix A whose eigenvalues characterize the behavior of the nearby points (Hartman-Grobman theorem). More precisely, if all eigenvalues are negative real numbers or complex numbers with negative real parts then the point is a stable attracting fixed point, and the nearby points converge to it at an exponential rate, cf Lyapunov stability and exponential stability. If none of the eigenvalues is purely imaginary (or zero) then the attracting and repelling directions are related to the eigenspaces of the matrix A with eigenvalues whose real part is negative and, respectively, positive. Analogous statements are known for perturbations of more complicated orbits.For the structure system in balance,if making it vibrate by applying small interference vibration,the structure of the deformation and vibration acceleration is relation to the structure load. When the load is less than the limit load of a stable value, the acceleration and deformation is in the opposite direction, so the interference is removed, the sports tend to be static and the structure of the equilibrium state is stable; When the load is greater than the ultimate load of stability, the acceleration and deformation is in the same direction, even to remove interference, movement are still divergent, therefore the structure of the equilibrium state is unstable. The critical state load is the buckling load of the structure,which can be made of the conditions that the structure vibration frequency is zero solution.At present, a lot of steel structure design with the aid of computer software for structural steel structure stress calculation, structure and component within the plane of strength and the overall stability calculation program automatically, can be counted on the structure and component of the out-of-plane strength and stability calculation, designers need to do another analysis, calculation and design. At this time the entire structure can be in the form of elevation is decomposed into a number of different layout structure, under different levels of load, the structure strength and stability calculation.local stability after buckling strength of the beam, it can be set up to the beam transverse or longitudinal stiffener, in order to solve the problem, the local stability of the beam stiffening rib according to Specification for Design of Steel Structures (GB50017-2003) ; Finite element analysis for a web after buckling strength calculation according to specification for design of steel structures (GB50017-2003) 4, 4 provisions. Axial compression member and a local bending component has two ways: one is the control board free overhanging flange width and thickness ratio of; The second is to control web computing the ratio of the height and thickness. For circular tube sectioncompression member, should control the ratio of outer diameter and wall thickness and stiffener according to specification for design of steel structures (GB50017-2003), 5 4 rule.4.ConclusionSteel structure has advantages of light weight, high strength and high degree of industrialization and has been widely used in the construction engineering.I believe that through to strengthen the overall stability and local stability of the structure and the design of out-of-plane stability, we could overcome structure design flaws and its application field will be more and more widely.referencesGB50017-2003,Design Code for Steel Structures[S]Chen Shaofan, Steel structure design principle [M]. Beijing: China building industry press, 2004 Kalman R.E. & Bertram J.F: Control System Analysis and Design via the Second Method of Lyapunov, J. Basic Engrg vol.88 1960 pp.371; 394LaSalle J.P. & Lefschetz S: Stability by Lyapunov's Second Method with Applications, New York 1961 (Academic)Smith M.J. and Wisten M.B., A continuous day-to-day traffic assignment model and the existence of a continuous dynamic user equilibrium , Annals of Operations Research, V olume 60, 1995 Arnold, V. I. (1988). Geometric methods in the theory of differential equations. Grundlehren der Mathematischen Wissenschaften, 250. Springer-Verlag, New York. ISBN 0-387-96649-8 Structural stability at Scholarpedia, curated by Charles Pugh and Maurício Matos Peixoto.。
钢结构毕业设计
前言伴随着我国经济与科学技术的快速发展，钢结构已逐步在工业厂房，商业大楼，民用住宅，大型场馆等公共建筑中被广泛采用。
钢材的强度高，故在结构中占体积小，因而建筑的实用空间就较大；钢结构可以成套预制装配，故施工方便；钢材可以回炉重新利用，故钢结构的再生性好。
钢结构有着非常多的优点，我国的钢结构事业也正处在蓬勃发展中。
轻型钢结构除具有普通钢结构的材质均匀，可靠性高；强度高，重量轻；塑性韧性，抗震性能好；便于机械化制造，施工期短；可回收，建筑造型美观等特点以外，一般还具有取材方便，用料较省，自重更轻等特点。
它对加快基本建设速度，特别对中小型企业的建设，以及对现有企业的挖潜、革新、改造等工作能够起到显著的作用，因而受到建设单位，尤其是在工业建筑中的普遍欢迎。
由于轻型钢结构的经济指标很好，总造价较低，再加上结构自重轻为改革重型结构体系创造了条件。
因此，轻型钢结构是很有发展前途的一种结构形势。
基于以上对轻型钢结构的认识，我在毕业设计课题中选择了轻型钢结构设计。
本次设计的是万利集团民用工业园的轻钢结构房屋工程。
通过这次设计，我希望能对钢结构的计算原理、轻型钢结构的特点和构造要求有一个较系统的认识。
同时，通过这次设计，培养自己理论结合实践的能力，积累工程经验，从而为将来走向工作岗位打下坚实的基础。
摘要近年来，轻钢结构因其取材方便、用料省、自重轻、构件批量生产、现场施工速度快、周期短等诸多特点，在我国取得了长足的发展。
其中，门式刚架造型由于其简洁美观、平面布置灵活、安装便利及可以满足多种生产工艺和使用功能的要求等特点，目前正被运用于越来越多的钢结构房屋建筑中。
本工程是以轻型门式钢架作为结构形式的单层工业厂房。
厂房共有两跨，每跨设有两台桥式软钩吊车。
厂房为双坡屋面，除基础和地基梁使用混凝土、外墙标高以下为240厚砖墙外，其他所有主次要构件均为钢结构。
首先根据现有资料进行建筑方案的比选及建筑的平、立、剖面的设计；然后建筑设计基础之上的结构布置、静力计算、框架设计、节点设计、柱脚设计、檩条设计、柱间支撑设计、吊车梁设计及基础设计等。
钢结构厂房开题报告加外文翻译
南京理工大学毕业设计(论文)开题报告学生姓名：邓逸欣学号：532110140301专业：土木工程设计(论文)题目：仁厚重型加工车间设计指导教师:惠颖2015年12月02日开题报告填写要求1．开题报告作为毕业设计（论文）答辩委员会对学生答辩资格审查的依据材料之一。
此报告应在指导教师指导下，由学生在毕业设计（论文）工作前期内完成，经指导教师签署意见及所在专业审查后生效；2．开题报告内容必须用黑墨水笔工整书写或按教务处统一设计的电子文档标准格式（可从继续教育学院网站上下载）打印，禁止打印在其它纸上后剪贴，完成后应及时交给指导教师签署意见；3．“文献综述”应按论文的格式成文，并直接书写（或打印）在本开题报告第一栏目内，学生写文献综述的参考文献应不少于15篇（不包括辞典、手册）；4．有关年月日等日期的填写，应当按照国标GB/T 7408—2005《数据元和交换格式、信息交换、日期和时间表示法》规定的要求，一律用阿拉伯数字书写。
如“2007年3月15日”或“2007-03-15”。
毕业设计（论文）开题报告仁厚重型加工车间设计摘要本设计为轻型钢结构厂房，采用轻型门式刚架体系，轻型钢结构建筑质量轻，强度高，跨度大，钢结构建筑施工工期短，相应降低投资成本，经济实惠。
它在我国有着较为广泛的应用前景。
轻型钢结构的屋面荷载较轻，因而杆件截面较小、较薄。
它除具有普通钢结构的自重较轻、材质均匀、应力计算准确可靠、加工制造简单、工业化程度高、运输安装方便等特点外，一般还具有取材方便、用料较省、自重更轻等优点。
本设计说明书包括建筑设计，结构设计两部分。
建筑设计部分具体为建筑平面形式的选择，厂房剖面设计，厂房立面设计，厂房的构造设计，门窗明细表。
结构设计部分包括方案选择，吊车梁设计，檩条设计，抗风柱设计，牛腿设计，刚架设计（内力组合），节点设计。
各章节都详细演算了主要构件的计算过程。
本次设计图纸部分有：厂房平面图，立面剖面及节点详图，刚架施工图，厂房檩条墙梁布置图，吊车梁施工图，支撑布置图，基础平面布置图。
钢结构毕业设计
钢结构毕业设计毕业设计（论文）课题名称接头焊缝的设计系别土木系专业建筑工程技术班级08级统招专科建筑工程技术一班姓名学号指导老师毕业设计（论文）任务书系土木系专业建筑工程技术年级大三班级08统招专科建筑工程技术一班姓名起止日期2022年1月3日至2月3日设计题目设计角钢连接的角焊缝1．毕业设计（论文）任务及要求（包括设计或论文的主要内容、主要技术指标，并根据题目性质对学生提出具体要求）本文介绍在不同角焊缝连接方式的等边角钢，根据被焊构件承受的轴力计算出每种连接方式的焊缝应力值并进行验算。
关键词：等边角钢、轴力、侧面角焊缝、L型围焊连接、三面围焊连接使用两根等边的角钢L110某10和强度为Q235的搭接板用角焊缝连接起来，如下图所示，焊接方法为手工焊，所用焊条为E43型。
根据构造要求和强度要求并按照侧面角焊缝、L型围焊连接和三面围焊连接三种角焊缝的连接方式设计出角焊缝的焊角尺寸与长度，被焊构件所受的轴力为700kN。
在设计过程中须写出完整的计算书，详细算出各种脚焊缝连接下各条焊缝上的应力值并进行强度验算。
1、刚结构，钟山桐，武汉大学出版社2、钢结构原理与设计（精编本），刘声扬等，武汉理工大学出版社3、钢结构，魏明钟，武汉理工大学出版社4、钢结构基本原理，沈祖炎等，中国建筑工业出版社指导教师年月日2指导教师评语建议成绩：优良中及格不及格指导教师签字3年月日最终评定成绩：优良中及格不及格系主任签字年月日4目录打印格式目录绪言5一、钢结构的角焊缝6(一)、角钢与钢板用角焊缝的连接形式61、两个侧面焊缝2、三面围焊3、L形围焊(二)、计算角焊缝的长度61、对于两面侧焊2、对于三面围焊3、当杆件受力很小时，可采用L形围焊。
二、角焊缝受轴心力作用的计算8(一)、侧面角焊缝或作用力平行于焊缝长度方向的角焊缝8(二)、正面角焊缝或作用力与焊缝长度方向垂直的角焊缝8三、按照不同形式的角焊缝连接根据构造要求和强度要求设计出角焊缝的焊脚尺寸与长度，并算出各条焊缝上的应力值进行强度验算8(一)、侧面角焊接81、计算焊脚尺寸和长度2、各条焊缝上的强度验算(二)、三面围焊91、计算焊角尺寸和长度2、各条焊缝上的强度验算（三）、L形围焊101、计算焊角尺寸和长度2、各条焊缝上的强度验算四、总结11五、参考文献125正文打印格式1．字号：标题的字号：一、小三、加粗。
钢结构桥梁中英文对照外文翻译文献
中英文对照外文翻译文献(文档含英文原文和中文翻译)Recent Research and Design Developments in Steel and Composite Steel-concrete Structures in USAThe paper will conclude with a look toward the future of structural steel research.1. Research on steel bridgesThe American Association of State Transportation and Highway Officials (AASTHO) is the authority that promulgates design standards for bridges in the US. In 1994 it has issued a new design specification which is a Limit States Design standard that is based on the principles of reliability theory. A great deal of work went into the development of this code in the past decade, especially on calibration and on the probabilistic evaluation of the previous specification. The code is now being implemented in the design office, together with the introduction of the SystemeInternationale units. Many questions remain open about the new method of design, and there are many new projects that deal with the reliability studies of the bridge as a system. One such current project is a study to develop probabilistic models, load factors, and rational load-combination rules for the combined effects of live-load and wind; live-load and earthquake; live-load, wind and ship collision; and ship collision, wind, and scour. There are also many field measurements of bridge behavior, using modern tools of inspection and monitoring such as acoustic emission techniques and other means of non-destructive evaluation. Such fieldwork necessitates parallel studies in the laboratory, and the evolution of ever more sophisticated high-technology data transmission methods.America has an aging steel bridge population and many problems arise from fatigue and corrosion. Fatigue studies on full-scale components of the Williamsburg Bridge in New York have recently been completed at Lehigh University. A probabilistic AASTHO bridge evaluation regulation has been in effect since 1989, and it is employed to assess the future useful life of structures using rational methods that include field observation and measurement together with probabilistic analysis. Such an activity also fosters additional research because many issues are still unresolved. One such area is the study of the shakedown of shear connectors in composite bridges. This work has been recently completed at the University of Missouri.In addition to fatigue and corrosion, the major danger to bridges is the possibility of earthquake induced damage. This also has spawned many research projects on the repair and retrofit of steel superstructures and the supporting concrete piers. Many bridges in the country are being strengthened for earthquake resistance. One area that is receiving much research attention is the strengthening of concrete piers by "jacketing" them by sheets of high-performance reinforced plastic.The previously described research deals mainly with the behavior of existing structures and the design of new bridges. However, there is also a vigorous activity on novel bridge systems. This research is centered on the application of high-performance steels for the design of innovative plate and box-girder bridges, such as corrugated webs, combinations of open and closed shapes, and longer spansfor truss bridges. It should be mentioned here that, in addition to work on steel bridges, there is also very active research going on in the study of the behavior of prestressed concrete girders made from very high strength concrete. The performance and design of smaller bridges using pultruded high-performance plastic composite members is also being studied extensively at present. New continuous bridge systems with steel concrete composite segments in both the positive moment and the negative moment regions are being considered. Several researchers have developed strong capabilities to model the three-dimensional non-linear behavior of individual plate girders, and many studies are being performed on the buckling and post-buckling characteristics of such panion experimental studies are also made,especially on members built from high-performance steels. A full-scale bridge of such steel has been designed, and will soon be constructed and then tested under traffic loading. Research efforts are also underway on the study of the fatigue of large expansion joint elements and on the fatigue of highway sign structures.The final subject to be mentioned is the resurgence of studies of composite steel concrete horizontally curved steel girder bridges. A just completed project at the University of Minnesota monitored the stresses and the deflections in a skewed and curved bridge during all phases of construction, starting from the fabrication yard to the completed bridge.~ Excellent correlation was found to exist between the measured stresses and deformations and the calculated values. The stresses and deflections during construction were found to be relatively small, that is, the construction process did not cause severe trauma to the system. The bridge has now been tested under service loading, using fully loaded gravel trucks, for two years, and it will continue to be studied for further years to measure changes in performance under service over time. A major testing project is being conducted at the Federal Highway Administration laboratory in Washington, DC, where a half-scale curved composite girder bridge is currently being tested to determine its limit states. The test-bridge was designed to act as its own test-frame, where various portions can be replaced after testing. Multiple flexure tests, shear tests, and tests under combined bending and shear, are thus performed with realistic end-conditions and restraints. The experiments arealso modeled by finite element analysis to check conformance between reality and prediction. Finally design standards will be evolved from the knowledge gained. This last project is the largest bridge research project in the USA at the present time.From the discussion above it can be seen that even though there is no large expansion of the nation's highway and railroad system, there is extensive work going on in bridge research. The major challenge facing both the researcher and the transportation engineer is the maintenance of a healthy but aging system, seeing to its gradual replacement while keeping it safe and serviceable.2. Research on steel members and framesThere are many research studies on the strength and behavior of steel building structures. The most important of these have to do with the behavior and design of steel structures under severe seismic events. This topic will be discussed later in this paper. The most significant trends of the non-seismic research are the following: "Advanced" methods of structural analysis and design are actively studied at many Universities, notably at Cornell, Purdue, Stanford, and Georgia Tech Universities. Such analysis methods are meant to determine the load-deformation behavior of frames up to and beyond failure, including inelastic behavior, force redistribution, plastic hinge formation, second-order effects and frame instability. When these methods are fully operational, the structure will not have to undergo a member check, because the finite element analysis of the frame automatically performs this job. In addition to the research on the best approaches to do this advanced analysis, there are also many studies on simplifications that can be easily utilized in the design office while still maintaining the advantages of a more complex analysis. The advanced analysis method is well developed for in-plane behavior, but much work is yet to be done on the cases where bi-axial bending or lateraltorsional buckling must be considered. Some successes have been achieved, but the research is far from complete.Another aspect of the frame behavior work is the study of the frames with semirigid joints. The American Institute of Steel Construction (AISC) has published design methods for office use. Current research is concentrating on the behavior ofsuch structures under seismic loading. It appears that it is possible to use such frames in some seismic situations, that is, frames under about 8 to 10 stories in height under moderate earthquake loads. The future of structures with semi-rigid frames looks very promising, mainly because of the efforts of researchers such as Leon at Georgia Tech University, and many others.Research on member behavior is concerned with studying the buckling and post buckling behavior of compact angle and wide-flange beam members by advanced commercial finite element programs. Such research is going back to examine the assumptions made in the 1950s and 1960s when the plastic design compactness and bracing requirements were first formulated on a semi-empirical basis. The non-linear finite element computations permit the "re-testing" of the old experiments and the performing of new computer experiments to study new types of members and new types of steels. White of Georgia Tech is one of the pioneers in this work. Some current research at the US military Academy and at the University of Minnesota by Earls is discussed later in this report. The significance of this type of research is that the phenomena of extreme yielding and distortion can be efficiently examined in parameter studies performed on the computer. The computer results can be verified with old experiments, or a small number of new experiments. These studies show a good prospect fornew insights into old problems that heretofore were never fully solved.3. Research on cold-formed steel structuresNext to seismic work, the most active part of research in the US is on cold-formed steel structures. The reason for this is that the supporting industry is expanding, especially in the area of individual family dwellings. As the cost of wood goes up, steel framed houses become more and more economical. The intellectual problems of thin-walled structures buckling in multiple modes under very large deformations have attracted some of the best minds in stability research. As a consequence, many new problems have been solved: complex member stiffening systems, stability and bracing of C and Z beams, composite slabs, perforated columns, standing-seam roof systems, bracing and stability of beams with very complicatedshapes, cold-formed members with steels of high yield stress-to-tensile strength ratio, and many other interesting applications. The American Iron and Steel Institute (AISI) has issued a new expanded standard in 1996 that brought many of these research results into the hands of the designer.4. Research on steel-concrete composite structuresAlmost all structural steel bridges and buildings in the US are built with composite beams or girders. In contrast, very few columns are built as composite members. The area of composite Column research is very active presently to fill up the gap of technical information on the behavior of such members. The subject of steel tubes filled with high-strength concrete is especially active. One of the aims of research performed by Hajjar at the University of Minnesota is to develop a fundamental understanding of the various interacting phenomena that occur in concrete-filled columns and beam-columns under monotonic and cyclic load. The other aim is to obtain a basic understanding of the behavior of connections of wide-flange beams to concrete filled tubes.Other major research work concerns the behavior and design of built-up composite wide-flange bridge girders under both positive and negative bending. This work is performed by Frank at the University of Texas at Austin and by White of Georgia Tech, and it involves extensive studies of the buckling and post-buckling of thin stiffened webs. Already mentioned is the examination of the shakedown of composite bridges. The question to be answered is whether a composite bridge girder loses composite action under repeated cycles of loads which are greater than the elastic limit load and less than the plastic mechanism load. A new study has been initiated at the University of Minnesota on the interaction between a semi-rigid steel frame system and a concrete shear wall connected by stud shear connectors.5. Research on connectionsConnection research continues to interest researchers because of the great variety of joint types. The majority of the connection work is currently related to the seismic problems that will be discussed in the next section of this paper. The most interest in non-seismic connections is the characterization of the monotonic moment-rotationbehavior of various types of semi-rigid joints.6. Research on structures and connections subject to seismic forcesThe most compelling driving force for the present structural steel research effort in the US was the January 17, 1994 earthquake in Northridge, California, North of Los Angeles. The major problem for steel structures was the extensive failure of prequalified welded rigid joints by brittle fracture. In over 150 buildings of one to 26 stories high there were over a thousand fractured joints. The buildings did not collapse, nor did they show any external signs of distress, and there were no human injuries or deaths. A typical joint is shown in Fig. 2.2.1.In this connection the flanges of the beams are welded to the flanges of the column by full-penetration butt welds. The webs are bolted to the beams and welded to the columns. The characteristic features of this type of connection are the backing bars at the bottom of the beam flange, and the cope-holes left open to facilitate the field welding of the beam flanges. Fractures occurred in the welds, in the beam flanges, and/or in the column flanges, sometimes penetrating into the webs.Once the problem was discovered several large research projects were initiated at various university laboratories, such as The University of California at San Diego, the University of Washington in Seattle, the University of Texas at Austin, Lehigh University at Bethlehem, Pennsylvania, and at other places. The US Government under the leadership of the Federal Emergency Management Agency (FEMA) instituted a major national research effort. The needed work was deemed so extensivethat no single research agency could hope to cope with it. Consequently three California groups formed a consortium which manages the work:(1) Structural Engineering Association of California.(2) Applied Technology Council.(3) California Universities for Research in Earthquake Engineering.The first letters in the name of each agency were combined to form the acronym SAC, which is the name of the joint venture that manages the research. We shall read much from this agency as the results of the massive amounts of research performed under its aegis are being published in the next few years.The goals of the program are to develop reliable, practical and cost-effective guidelines for the identification and inspection of at-risk steel moment frame buildings, the repair or upgrading of damaged buildings, the design of new construction, and the rehabilitation of undamaged buildings.~ As can be seen, the scope far exceeds the narrow look at the connections only. The first phase of the research was completed at the end of 1996, and its main aim was to arrive at interim guidelines so that design work could proceed. It consisted of the following components:~ A state-of-the-art assessment of knowledge on steel connections.~ A survey of building damage.~ The evaluation of ground motion.~ Detailed building analyses and case studies.~ A preliminary experimental program.~ Professional training and quality assurance programs.~ Publishing of the Interim Design Guidelines.A number of reports were issued in this first phase of the work. A partial list of these is appended at the end of this paper.During the first phase of the SAC project a series of full-scale connection tests under static and, occasionally, dynamic cyclic tests were performed. Tests were of pre-Northridge-type connections (that is, connections as they existed at the time of the earthquake), of repaired and upgraded details, and of new recommendedconnection details. A schematic view of the testing program is illustrated in Fig.2.2.2 Some recommended strategies for new design are schematically shown in Fig. 2.2.3.Fig. 2.2.3 some recommended improvements in the interim guidelinesThe following possible causes, and their combinations, were found to have contributed to tile connection failures:~ Inadequate workmanship in the field welds.~ Insufficient notch-toughness of the weld metal.~ Stress raisers caused by the backing bars.~ Lack of complete fusion near the backing bar.~ Weld bead sizes were too big.~ Slag inclusion in the welds.While many of the failures can be directly attributed to the welding and thematerial of the joints, there are more serious questions relative to the structural system that had evolved over the years mainly based on economic considerations.' The structural system used relatively few rigid-frames of heavy members that were designed to absorb the seismic forces for large parts of the structure. These few lateral-force resistant frames provide insufficient redundancy. More rigid-frames with smaller members could have provided a tougher and more ductile structural system. There is a question of size effect: Test results from joints of smaller members were extrapolated to joints with larger members without adequate test verification. The effect of a large initial pulse may have triggered dynamic forces that could have caused brittle fracture in joints with fracture critical details and materials. Furthermore, the yield stress of the beams was about 30% to 40% larger than the minimum specified values assumed in design, and so the connection failed before the beams, which were supposed to form plastic hinges.As can be seen, there are many possible reasons for this massive failure rate, and there is blame to go around for everyone. No doubt, the discussion about why and how the joints failed will go on for many more years. The structural system just did not measure up to demands that were more severe than expected. What should be kept in mind, however, is that no structure collapsed or caused even superficial nonstructural damage, and no person was injured or killed. In the strictest sense the structure sacrificed itself so that no physical harm was done to its users. The economic harm, of course, was enormous.7. Future directions of structural steel research and conclusionThe future holds many challenges for structural steel research. The ongoing work necessitated by the two recent earthquakes that most affected conventional design methods, namely, the Northridge earthquake in the US and the Kobe earthquake in Japan, will continue well into the first decade of the next Century. It is very likely that future disasters of this type will bring yet other problems to the steel research community. There is a profound change in the philosophy of design for disasters: We can no longer be content with saving lives only, but we must also design structures which will not be so damaged as to require extensive repairs.Another major challenge will be the emergence of many new materials such as high-performance concrete and plastic composite structures. Steel structures will continually have to face the problem of having to demonstrate viability in the marketplace. This can only be accomplished by more innovative research. Furthermore, the new comprehensive limit-states design codes which are being implemented worldwide, need research to back up the assumptions used in the theories.Specifically, the following list highlights some of the needed research in steel structures:Systems reliability tools have been developed to a high degree of sophistication. These tools should be applied to the studies of bridge and building structures to define the optimal locations of monitoring instruments, to assess the condition and the remaining life of structures, and to intelligently design economic repair and retrofit operations.New developments in instrumentation, data transfer and large-scale computation will enable researchers to know more about the response of structures under severe actions, so that a better understanding of "real-life" behavior can be achieved.The state of knowledge about the strength of structures is well above the knowledge about serviceability and durability. Research is needed on detecting and preventing damage in service and from deterioration.The areas of fatigue and fracture mechanics on the one hand, and the fields of structural stability on the other hand, should converge into a more Unified conceptual entity.The problems resulting from the combination of inelastic stability and low-cycle fatigue in connections subject to severe cyclic loads due to seismic action will need to be solved.The performance of members, connections and connectors (e.g., shear connectors) under severe cyclic and dynamic loading requires extensive new research, including shakedown behavior.The list could go on, but one should never be too dogmatic about the future ofsuch a highly creative activity as research. Nature, society and economics will provide sufficient challenges for the future generation of structural engineers.近期美国在钢结构和钢筋混凝土结构研究和设计方面的发展这篇文章将总结对钢结构的研究展望.1.钢结构桥梁的研究美国国家运输和公路官员协会(AASTH0)是为美国桥梁发布设计标准的权威。
钢结构毕业设计论文
钢结构毕业设计论文摘要：钢结构作为一种重要的建筑结构形式，在现代建筑领域得到了广泛应用。
本文主要研究了钢结构的设计原理、施工工艺以及相关的优缺点，通过实际案例分析探讨了钢结构在建筑中的应用和发展趋势。
通过对钢结构的研究和分析可以发现，钢结构具有高强度、抗震、可塑性好等优点，但也存在着腐蚀、施工难度大等缺点。
因此，钢结构在设计和施工过程中需要加以合理的考虑和应用。
关键词：钢结构、设计原理、施工工艺、优缺点、应用、发展趋势1、引言钢结构是以钢材为主要材料，通过连接构件组成的一种建筑结构形式。
钢结构具有很高的强度、刚度和稳定性，广泛应用于各类建筑中。
本文通过研究钢结构的设计原理和施工工艺，分析了钢结构在建筑中的应用和发展趋势。
2、钢结构的设计原理2.1强度设计原理钢结构的强度设计原理是基于材料的力学性能和结构的受力规律。
根据结构的荷载特点和强度要求，采用适当的钢材和截面形状，通过计算和验算确定各构件的强度和稳定性。
2.2刚度设计原理刚度设计原理是指通过控制结构的刚度，使结构在受力过程中不会产生过大的变形和挠度。
刚度设计主要考虑结构的刚度比例、节点设计和连接设计等因素，以保证结构的稳定和耐久性。
3、钢结构的施工工艺3.1组装式施工工艺组装式施工工艺是指将钢构件在生产厂家进行预制后，通过运输和组装的方式进行建筑施工。
这种施工工艺可以提高施工效率和质量，减少工期和人力投入。
3.2简支梁施工工艺简支梁施工工艺是指将钢梁作为支撑结构，在搭设好临时支架后进行钢梁的安装和连接。
这种施工工艺适用于较长、较大跨度的梁结构，能够确保钢梁的水平度和稳定性。
4、钢结构的优缺点4.1优点钢结构具有高强度、抗震和可塑性好的特点，能够承受较大的荷载和变形。
此外，钢结构的施工周期短，能够提高建筑工程的进度和效率。
4.2缺点钢结构容易受到腐蚀的影响，需要进行防腐处理。
同时，钢结构的施工难度大，需要专业的人员进行施工和监督。
5、钢结构在建筑中的应用和发展趋势钢结构在高层建筑、工业厂房等领域得到了广泛应用。
高层结构与钢结构(中英论文翻译用)
高层结构与钢结构(中英论文翻译用) - 建筑技术高层结构与钢结构近年来，尽管一般的建筑结构设计取得了很大的进步，但是取得显著成绩的还要属超高层建筑结构设计。
最初的高层建筑设计是从钢结构的设计开始的。
钢筋混凝土和受力外包钢筒系统运用起来是比较经济的系统，被有效地运用于大批的民用建筑和商业建筑中。
50层到100层的建筑被定义为超高层建筑。
而这种建筑在美国得广泛的应用是由于新的结构系统的发展和创新。
这样的高度需要增大柱和梁的尺寸，这样以来可以使建筑物更加坚固以至于在允许的限度范围内承受风荷载而不产生弯曲和倾斜。
过分的倾斜会导致建筑的隔离构件、顶棚以及其他建筑细部产生循环破坏。
除此之外，过大的摇动也会使建筑的使用者们因感觉到这样的的晃动而产生不舒服的感觉。
无论是钢筋混凝土结构系统还是钢结构系统都充分利用了整个建筑的刚度潜力，因此不能指望利用多余的刚度来限制侧向位移。
在钢结构系统设计中，经济预算是根据每平方英寸地板面积上的钢材的数量确定的。
图示1中的曲线A显示了常规框架的平均单位的重量随着楼层数的增加而增加的情况。
而曲线B显示则显示的是在框架被保护而不受任何侧向荷载的情况下的钢材的平均重量。
上界和下界之间的区域显示的是传统梁柱框架的造价随高度而变化的情况。
而结构工程师改进结构系统的目的就是减少这部分造价。
钢结构中的体系：钢结构的高层建筑的发展是几种结构体系创新的结果。
这些创新的结构已经被广泛地应用于办公大楼和公寓建筑中。
刚性带式桁架的框架结构：为了联系框架结构的外柱和内部带式桁架，可以在建筑物的中间和顶部设置刚性带式桁架。
1974年在米望基建造的威斯康森银行大楼就是一个很好的例子。
框架筒结构：如果所有的构件都用某种方式互相联系在一起，整个建筑就像是从地面发射出的一个空心筒体或是一个刚性盒子一样。
这个时候此高层建筑的整个结构抵抗风荷载的所有强度和刚度将达到最大的效率。
这种特殊的结构体系首次被芝加哥的43层钢筋混凝土的德威特红棕色的公寓大楼所采用。
关于钢结构的英文作文
关于钢结构的英文作文英文：Steel structure is a popular choice for building construction due to its many advantages. Firstly, it is durable and can withstand harsh weather conditions and natural disasters such as earthquakes and hurricanes. This is because steel is a strong and flexible material that can absorb shock and resist deformation. Secondly, steel structures are easy to assemble and disassemble, making them ideal for temporary or mobile buildings such as exhibition halls or warehouses. Thirdly, steel is a sustainable material that can be recycled and reused, reducing waste and environmental impact.In addition, steel structures offer design flexibility and can be customized to meet specific requirements. For example, the shape and size of the structure can be adjusted to fit the available space and the intended use of the building. Moreover, steel structures can be combinedwith other materials such as glass, wood or concrete to create a unique and aesthetically pleasing design.However, there are also some challenges associated with steel structure construction. One of the main challenges is corrosion, which can weaken the structure over time. This can be prevented by applying protective coatings or using stainless steel. Another challenge is the cost, as steel structures can be more expensive than traditional building materials such as wood or brick. However, the long-term benefits of durability and sustainability may outweigh the initial cost.Overall, steel structure construction offers many advantages and is a viable option for building projects of various sizes and purposes.中文：钢结构是建筑施工中一个受欢迎的选择，因为它有许多优点。
土木工程专业毕业论文钢结构设计
土木工程专业毕业论文钢结构设计钢结构设计是土木工程专业中非常重要的一个方向。
随着工业化和城市化的发展，钢结构建筑在现代建筑中扮演着重要的角色。
本篇论文将讨论钢结构设计的关键问题，包括钢材的选择、结构设计方法和构造设计等方面。
首先，钢材的选择是钢结构设计中的一个关键问题。
钢材的性能直接影响到结构的安全性和经济性。
在选择钢材时，需要考虑到结构的受力情况、材料的强度和韧性等因素。
例如，在承受大荷载和较高应力的部位，需要选择高强度钢材；而在需要有一定韧性和可塑性的部位，需要选择韧性较好的钢材。
此外，还需要考虑到钢材的耐腐蚀性、耐火性和施工性能等因素。
因此，钢材的选择是钢结构设计中不可忽视的一个重要环节。
其次，在钢结构设计中，结构设计方法的选择也是一个关键问题。
结构设计方法的选择应基于结构的受力特点和要求。
例如，在正规的建筑中，常采用荷载法进行结构设计，即根据建筑使用要求和相关规范确定各个荷载的作用形式和大小，然后根据受力平衡条件进行结构计算。
而在一些特殊的结构中，如高层建筑和大跨度结构，则需要采用更为精细的分析方法，包括弹性分析、弹塑性分析和非线性分析等。
此外，还需要考虑到结构的抗震性和抗风性等因素。
最后，在钢结构设计中，构造设计也是一个重要环节。
构造设计涉及到结构的节点设计、连接设计和支承设计等。
在节点设计中，需要考虑到力的传递、材料的连接和结构的变形等因素。
在连接设计中，需要考虑到连接的强度、刚度和耐久性等。
在支承设计中，需要考虑到结构的稳定性和刚度等。
因此，构造设计需要综合考虑结构的力学性能和施工性能等因素。
综上所述，钢结构设计是土木工程专业中一个重要的方向。
钢结构设计涉及到钢材的选择、结构设计方法和构造设计等关键问题。
钢结构设计的质量直接影响到建筑的安全性和经济性。
因此，钢结构设计人员需要具备扎实的专业知识和丰富的实践经验，以保证结构设计的准确性和可靠性。
同时，钢结构设计人员还需要与各个相关专业进行密切的合作，以解决结构设计中的各种问题。
毕业设计论文化学系毕业论文外文文献翻译中英文
毕业设计论文化学系毕业论文外文文献翻译中英文英文文献及翻译A chemical compound that is contained in the hands of the problemsfor exampleCatalytic asymmetric carbon-carbon bond formation is one of the most active research areas in organic synthesis In this field the application of chiral ligands in enantioselective addition of diethylzinc to aldehydes has attracted much attention lots of ligands such as chiral amino alcohols amino thiols piperazines quaternary ammonium salts 12-diols oxazaborolidines and transition metal complex with chiral ligands have been empolyed in the asymmetric addition of diethylzinc to aldehydes In this dissertation we report some new chiral ligands and their application in enantioselective addition of diethylzinc to aldehydes1 Synthesis and application of chiral ligands containing sulfur atomSeveral a-hydroxy acids were prepared using the literature method with modifications from the corresponding amino acids valine leucine and phenylalanine Improved yields were obtained by slowly simultaneous addition of three fold excess of sodium nitrite and 1 tnolL H2SO4 In the preparation of a-hydroxy acid methyl esters from a-hydroxy acids following the procedure described by Vigneron a low yield 45 was obtained It was found that much better results yield 82 couldbe obtained by esterifying a-hydroxy acids with methanol-thionyl chlorideThe first attempt to convert S -2-hydroxy-3-methylbutanoic acid methyl ester to the corresponding R-11-diphenyl-2-mercapto-3-methyl-l-butanol is as the following S-2-Hydroxy-3-methylbutanoic acid methyl ester was treated with excess of phenylmagnesium bromide to give S -11-diphenyl-3-methyl-12-butanediol which was then mesylated to obtain S -11-diphenyl-3-methyl-2-methanesulfonyloxy -l-butanol Unfortunately conversion of S-11-diphenyl-3-methyl-2- methanesulfonyloxy -l-butanol to the corresponding thioester by reacting with potassium thioacetate under Sn2 reaction conditions can be achieved neither in DMF at 20-60 nor in refluxing toluene in the presence of 18-crown-6 as catalyst When S -1ll-diphenyl-3-methyl-2- methane sulfonyloxy -l-butanol was refluxed with thioacetic acid in pyridine an optical active epoxide R-22-diphenyl -3-isopropyloxirane was obtained Then we tried to convert S -11-diphenyl-3-methyl-l2-butanediol to the thioester by reacting with PPh3 DEAD and thioacetic acid the Mitsunobu reaction but we failed either probably due to the steric hindrance around the reaction centerThe actually successful synthesis is as described below a-hydroxy acid methyl esters was mesylated and treated with KSCOCH3 in DMF to give thioester this was than treated with phenyl magnesium bromide to gave the target compound B-mercaptoalcohols The enantiomeric excesses ofp-mercaptoalcohols can be determined by 1H NMR as their S -mandeloyl derivatives S -2-amino-3-phenylpropane-l-thiol hydrochloride was synthesized from L-Phenylalanine L-Phenylalanine was reduced to the amino alcohol S -2-amino-3-phenylpropanol Protection of the amino group using tert-butyl pyrocarbonate gave S -2-tert-butoxycarbonylamino-3-phenylpropane-l-ol which was then O-mesylated to give S -2-tert-butoxycarbonylamino-3-phenylpropyl methanesulfonate The mesylate was treated with potassium thioacetate in DMF to give l-acetylthio-2-tert-butoxycarbonylamino-3-phenylpropane The acetyl group was then removed by treating with ammonia in alcohol to gave S -2-tert-butoxycarbonylamino-3-phenyl-propane-l-thiol which was then deprotected with hydrochloric acid to give the desired S-2-amino-3-phenylpropane-1-thiol hydrochlorideThe enantioselective addition of diethylzinc to aldehydes promoted by these sulfur containing chiral ligands produce secondary alcohols in 65-79 Synthesis and application of chiral aminophenolsThree substituted prolinols were prepared from the naturally-occurring L-proline using reported method with modifications And the chiral aminophenols were obtained by heating these prolinols with excess of salicylaldehyde in benzene at refluxThe results of enantioselective adBelow us an illustration forexampleN-Heterocyclic carbenes and L-Azetidine-2-carboxylicacidN-Heterocyclic carbenesN-Heterocyclic carbenes have becomeuniversal ligands in organometallic and inorganic coordination chemistry They not only bind to any transition metal with low or high oxidation states but also to main group elements such as beryllium sulfur and iodine Because of their specific coordination chemistry N-heterocyclic carbenes both stabilize and activate metal centers in quite different key catalytic steps of organic syntheses for example C-H activation C-C C-H C-O and C-N bond formation There is now ample evidence that in the new generation of organometallic catalysts the established ligand class of organophosphanes will be supplemented and in part replaced byN-heterocyclic carbenes Over the past few years this chemistry has become the field of vivid scientific competition and yielded previously unexpected successes in key areas of homogeneous catalysis From the work in numerous academic laboratories and in industry a revolutionary turningpoint in oraganometallic catalysis is emergingIn this thesis Palladium Ⅱ acetate and NN"-bis- 26-diisopropylphenyl dihydro- imidazolium chloride 1 2 mol were used to catalyze the carbonylative coupling of aryl diazonium tetrafluoroborate salts and aryl boronic acids to form aryl ketones Optimal conditions include carbon monoxide 1 atm in 14-dioxane at 100℃ for 5 h Yields for unsymmetrical aryl ketones ranged from 76 to 90 for isolated materials with only minor amounts of biaryl coupling product observed 2-12 THF as solvent gave mixtures of products 14-Dioxane proved to be the superior solvent giving higher yieldsof ketone product together with less biphenyl formation At room temperature and at 0℃ with 1 atm CO biphenyl became the major product Electron-rich diazonium ion substrates gave a reduced yield with increased production of biaryl product Electron-deficient diazonium ions were even better forming ketones in higher yields with less biaryl by-product formed 2-Naphthyldiazonium salt also proved to be an effective substrate givingketones in the excellent range Base on above palladium NHC catalysts aryl diazonium tetrafluoroborates have been coupled with arylboron compounds carbon monoxide and ammonia to give aryl amides in high yields A saturated yV-heterocyclic carbene NHC ligand H2lPr 1 was used with palladium II acetate to give the active catalyst The optimal conditions with 2mol palladium-NHC catalyst were applied with various organoboron compounds and three aryl diazonium tetrafluoroborates to give numerous aryl amides in high yield using pressurized CO in a THF solution saturated with ammonia Factors that affect the distribution of the reaction products have been identified and a mechanism is proposed for this novel four-component coupling reactionNHC-metal complexes are commonly formed from an imidazolium salt using strong base Deprotonation occurs at C2 to give a stable carbene that adds to form a a-complex with the metal Crystals were obtained from the reaction of imidazolium chloride with sodium t- butoxide Nal and palladium II acetate giving a dimeric palladium II iodide NHC complex The structure adopts a flat 4-memberedring u2 -bridged arrangement as seen in a related dehydro NHC complex formed with base We were pleased to find that chloride treated with palladium II acetate without adding base or halide in THF also produced suitable crystals for X-ray anaysis In contrast to the diiodide the palladium-carbenes are now twisted out of plane adopting a non-planar 4-ring core The borylation of aryldiazonium tetrafluoroborates with bis pinacolatoborane was optimized using various NHC ligand complexes formed in situ without adding base NN"-Bis 26-diisopropylphenyl-45-dihydroimidazolium 1 used with palladium acetate in THF proved optimal giving borylated product in 79 isolated yield without forming of bi-aryl side product With K2CO3 and ligand 1 a significant amount of biaryl product 24 was again seen The characterization of the palladium chloride complex by X-ray chrastallography deL-Azetidine-2-carboxylic acidL-Azetidine-2-carboxylic acid also named S -Azetidine-2-carboxylic acid commonly named L-Aze was first isolated in 1955 by Fowden from Convallaria majalis and was the first known example of naturally occurring azetidine As a constrained amino acid S -Azetidine-2-carboxylic acid has found many applications in the modification of peptides conformations and in the area of asymmetric synthesis which include its use in the asymmetric reduction of ketones Michael additions cyclopropanations and Diels-Alder reactions In this dissertation five ways for synthesize S-Azetidine-2-carboxylic acid were studied After comparing all methods theway using L-Aspartic acid as original material for synthesize S-Azetidine-2-carboxylic acid was considered more feasible All mechanisms of the way"s reaction have also been studied At last the application and foreground of S -Azetidine-2-carboxylic acid were viewed The structures of the synthetic products were characterized by ThermalGravity-Differential Thermal Analysis TG-DTA Infrared Spectroscopy IR Mass Spectra MS and 1H Nuclear Magnetic Resonance 1H-NMR Results showed that the structures and performances of the products conformed to the anticipation the yield of each reaction was more than 70 These can conclude that the way using L-Aspartie acid as original material for synthesize S -Azetidine-2-carboxylic acid is practical and effective杂环化合物生成中包含手性等问题如催化形成不对称碳碳键在有机合成中是一个非常活跃的领域在这个领域中利用手性配体诱导的二乙基锌和醛的不对称加成引起化学家的广泛关注许多手性配体如手性氨基醇手性氨基硫醇手性哌嗪手性四季铵盐手性二醇手性恶唑硼烷和过渡金属与手性配体的配合物等被应用于二乙基锌对醛的不对称加成中在本论文中我们报道了一些新型的手性配体的合成及它们应用于二乙基锌对醛的不对称加成的结果1含硫手性配体的合成和应用首先从氨基酸缬氨酸亮氨酸苯丙氨酸出发按照文献合成α-羟基酸并发现用三倍量的亚硝酸钠和稀硫酸同时滴加进行反应能适当提高反应的产率而根据Vigneron等人报道的的方法用浓盐酸催化从α-羟基酸合成α-羟基酸甲酯时只能获得较低的产率改用甲醇-二氯亚砜的酯化方法时能提高该步骤的产率从 S -3-甲基-2-羟基丁酸甲酯合成 R -3-甲基-11-二苯基-2-巯基-1-丁醇经过了以下的尝试 S -3-甲基-2-羟基丁酸甲酯和过量的格氏试剂反应得到 S -3-甲基-11-二苯基-12-丁二醇进行甲磺酰化时位阻较小的羟基被磺酰化生成 S -3-甲基-11-二苯基-2- 甲磺酰氧基 -1-丁醇但无论将 S -3-甲基-11-二苯基-2- 甲磺酰氧基 -1-丁醇和硫代乙酸钾在DMF中反应 20～60℃还是在甲苯中加入18-冠-6作为催化剂加热回流都不能得到目标产物当其与硫代乙酸在吡啶中回流时得到的不是目标产物而是手性环氧化合物 R -3-异丙基-22-二苯基氧杂环丙烷从化合物 S -3-甲基-11-二苯基-12-丁二醇通过Mitsunobu反应合成硫代酯也未获得成功这可能是由于在反应中心处的位阻较大造成的几奥斯塑手村犯体的合成裁其在不对称奋成中肠左用摘要成功合成疏基醇的合成路是将a-轻基酸甲酷甲磺酞化得到相应的磺酞化产物并进行与硫代乙酸钾的亲核取代反应得到硫酷进行格氏反应后得到目标分子p一疏基醇用p一疏基醇与 R 义一一甲氧基苯乙酞氯生成的非对映体经H侧NM吸测试其甲氧基峰面积的积分求得其ee值 3一苯基一氨基丙硫醇盐酸盐从苯丙氨酸合成斗3一苯基一氨基丙醇由L一苯丙氨酸还原制备氨基保护后得到习一3一苯基一2一叔丁氧拨基氨基一1一丙醇甲磺酞化后得到习一3一苯基一2一叔丁氧拨基氨基一1一丙醇甲磺酸酷用硫代乙酸钾取代后得匀一3-苯基一2一叔丁氧拨基氨基一1一丙硫醇乙酸酷氨解得习一3一苯基一2一叔丁氧拨基氨基一1一丙硫醇用盐酸脱保护后得到目标产物扔3一苯基屯一氨基丙硫醇盐酸盐手性含硫配体诱导下的二乙基锌与醛的加成所得产物的产率为65一79值为O井92手性氨基酚的合成和应用首先从天然的L一脯氨酸从文献报道的步骤合成了三种脯氨醇这些手性氨基醇与水杨醛在苯中回流反应得到手性氨基酚手性氨基酚配体诱导下的二乙基锌与醛的加成所得产物的产率为45一98值为0一90手性二茂铁甲基氨基醇的合成和应用首先从天然氨基酸绿氨酸亮氨酸苯丙氨酸和脯氨酸合成相应的氨基醇这些氨基醇与二茂铁甲醛反应生成的NO一缩醛经硼氢化钠还原得到手性二茂铁甲基氨基醇手性二茂铁甲基氨基醇配体诱导下的二乙基锌与醛的加成所得产物的产率为66一97下面我们举例说明一下例如含氮杂环卡宾和L-氮杂环丁烷-2-羧酸含氮杂环卡宾含氮杂环卡宾已广泛应用于有机金属化学和无机配合物化学领域中它们不仅可以很好地与任何氧化态的过渡金属络合还可以与主族元素铍硫等形成配合物由于含氮杂环卡宾不但使金属中心稳定而且还可以活化此金属中心使其在有机合成中例如C-H键的活化C-CC-HC-O和C-N键形成反应中有着十分重要的催化效能现有的证据充分表明在新一代有机金属催化剂中含氮杂环卡宾不但对有机膦类配体有良好的互补作用而且在有些方面取代有机膦配体成为主角近年来含氮杂环卡宾及其配合物已成为非常活跃的研究领域在均相催化这一重要学科中取得了难以想象的成功所以含氮杂环卡宾在均相有机金属催化领域的研究工作很有必要深入地进行下去本文研究了乙酸钯和NN双 26-二异丙基苯基 -45-二氢咪唑氯化物1作为催化剂催化芳基四氟硼酸重氮盐与芳基硼酸的羰基化反应合成了一系列二芳基酮并对反应条件进行了优化使反应在常温常压下进行一个大气压的一氧化碳14-二氧杂环己烷作溶剂100℃反应5h 不同芳基酮的收率达7690仅有微量的联芳烃付产物 212 反应选择性良好当采用四氢呋喃或甲苯作溶剂时得到含较多副产物的混合物由此可以证明14-二氧杂环己烷是该反应最适宜的溶剂在室温或0℃与一个大气压的一氧化碳反应联芳烃变成主产物含供电子取代基的芳基重氮盐常常给出较低收率的二芳基酮而含吸电子取代基的芳基重氮盐却给出更高收率的二芳基酮及较少量的联芳烃付产物实验证明2-萘基重氮盐具有很好的反应活性和选择性总是得到优异的反应结果在此基础上由不同的芳基四氟硼酸重氮盐与芳基硼酸一氧化碳和氨气协同作用以上述含氮杂环卡宾作配体与乙酸钯生成的高活性含氮杂环卡宾钯催化剂催化较高收率地得到了芳基酰胺优化的反应条件是使用2mol的钯-H_2IPr 1五个大气压的一氧化碳以氨气饱和的四氢呋喃作溶剂由不同的有机硼化合物与三种芳基重氮盐的四组份偶联反应同时不仅对生成的多种产物进行了定 L-氮杂环丁烷-2-羧酸L-氮杂环丁烷-2-羧酸又称 S -氮杂环丁烷-2-羧酸简称为L-Aze1955年由Fowden从植物铃兰 Convallaria majalis 中分离得到成为第一个被证实的植物中天然存在的氮杂环丁烷结构作为一种非典型的氨基酸已经发现 S -氮杂环丁烷-2-羧酸可广泛用于对多肽结构的修饰以及诸如不对称的羰基还原Michael 加成环丙烷化和Diels-Alder反应等不对称合成中的多个领域本文通过对 S -氮杂环丁烷-2-羧酸合成路线的研究综述了五种可行的合成路线及方法通过比较选用以L-天冬氨酸为初始原料合成 S -氮杂环丁烷-2-羧酸的路线即通过酯化反应活泼氢保护格氏反应内酰胺化反应还原反应氨基保护氧化反应脱保护等反应来合成 S -氮杂环丁烷-2-羧酸分析了每步反应的机理并对 S -氮杂环丁烷-2-羧酸的应用及前景给予展望通过热分析红外质谱核磁等分析手段对合成的化合物的结构进行表征结果表明所得的产物符合目标产物所合成的化合物的结构性能指标与设计的目标要求一致每步反应的收率都在70％以上可以判定以L-天冬氨酸为初始原料合成 S -氮杂环丁烷的路线方案切实可行。
土木工程-毕业设计-论文-外文翻译-中英文对照
英文原文：Concrete structure reinforcement designSheyanb oⅠWangchenji aⅡⅠFoundation Engineering Co., Ltd. Heilongjiang DongyuⅡHeilongjiang Province, East Building Foundation Engineering Co., Ltd. CoalAbstract：structure in the long-term natural environment and under the use environment's function, its function is weaken inevitably gradually, our structural engineering's duty not just must finish the building earlier period the project work, but must be able the science appraisal structure damage objective law and the degree, and adopts the effective method guarantee structure the security use, that the structure reinforcement will become an important work. What may foresee will be the 21st century, the human building also by the concrete structure, the steel structure, the bricking-up structure and so on primarily, the present stage I will think us in the structure reinforcement this aspect research should also take this as the main breakthrough direction.Key word：Concrete structure reinforcement bricking-up structure reinforcement steel structure reinforcement1 Concrete structure reinforcementConcrete structure's reinforcement divides into the direct reinforcement and reinforces two kinds indirectly, when the design may act according to the actual condition and the operation requirements choice being suitable method and the necessary technology.1.1the direct reinforcement's general method1）Enlarges the section reinforcement lawAdds the concretes cast-in-place level in the reinforced concrete member in bending compression zone, may increase the section effective height, the expansion cross sectional area, thus enhances the component right section anti-curved, the oblique section anti-cuts ability and the section rigidity, plays the reinforcement reinforcement the role.In the suitable muscle scope, the concretes change curved the component right section supporting capacity increase along with the area of reinforcement and the intensity enhance. In the original component right section ratio of reinforcement not too high situation, increases the main reinforcement area to be possible to propose the plateau component right section anti-curved supporting capacity effectively. Is pulled in the section the area to add the cast-in-place concrete jacket to increase the component section, through new Canada partial and original component joint work, but enhances the component supporting capacity effectively, improvement normal operational performance.Enlarges the section reinforcement law construction craft simply, compatible, and has the mature design and the construction experience; Is suitable in Liang, the board, the column, the wall and the general structure concretes reinforcement; But scene construction's wet operating time is long, to produces has certain influence with the life, and after reinforcing the building clearance has certain reduction.2) Replacement concretes reinforcement lawThis law's merit with enlarges the method of sections to be close, and after reinforcing, does not affect building's clearance, but similar existence construction wet operating time long shortcoming; Is suitable somewhat low or has concretes carrier's and so on serious defect Liang, column in the compression zone concretes intensity reinforcement.3) the caking outsourcing section reinforcement lawOutside the Baotou Steel Factory reinforcement is wraps in the section or the steel plate is reinforced component's outside, outside the Baotou Steel Factory reinforces reinforced concrete Liang to use the wet outsourcing law generally, namely uses the epoxy resinification to be in the milk and so on methods with to reinforce the section the construction commission to cake a whole, after the reinforcement component, because is pulled with the compressed steel cross sectional area large scale enhancement, therefore right section supporting capacity and section rigidity large scale enhancement.This law also said that the wet outside Baotou Steel Factory reinforcement law, the stress is reliable, the construction is simple, the scene work load is small, but is big with the steel quantity, and uses in above not suitably 600C in the non-protection's situation the high temperature place; Is suitable does not allow in the use obviously to increase the original component section size, but requests to sharpen its bearing capacity large scale the concrete structure reinforcement.4) Sticks the steel reinforcement lawOutside the reinforced concrete member in bending sticks the steel reinforcement is (right section is pulled in the component supporting capacity insufficient sector area, right section compression zone or oblique section) the superficial glue steel plate, like this may enhance is reinforced component's supporting capacity, and constructs conveniently.This law construction is fast, the scene not wet work or only has the plastering and so on few wet works, to produces is small with the life influence, and after reinforcing, is not remarkable to the original structure outward appearance and the original clearance affects, but the reinforcement effect is decided to a great extent by the gummy craft and the operational level; Is suitable in the withstanding static function, and is in the normal humidity environment to bend or the tension member reinforcement.5) Glue fibre reinforcement plastic reinforcement lawOutside pastes the textile fiber reinforcement is pastes with the cementing material the fibre reinforcement compound materials in is reinforced the component to pull the region, causes it with to reinforce the section joint work, achieves sharpens the component bearing capacity the goal. Besides has glues the steel plate similar merit, but also has anticorrosive muddy, bears moistly, does not increase the self-weight of structure nearly, durably, the maintenance cost low status merit, but needs special fire protection processing, is suitable in each kind of stress nature concrete structure component and the general construction.This law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.6) Reeling lawThis law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.7) Fang bolt anchor lawThis law is suitable in the concretes intensity rank is the C20~C60 concretes load-bearing member transformation, the reinforcement; It is not suitable for already the above structure which and the light quality structure makes decent seriously. 1.2The indirect reinforcement's general method1)Pre-stressed reinforcement law(1)Thepre-stressed horizontal tension bar reinforces concretes member in bending,because the pre-stressed and increases the exterior load the combined action, in the tension bar has the axial tension, this strength eccentric transmits on the component through the pole end anchor (, when tension bar and Liang board bottom surface close fitting, tension bar can look for tune together with component, this fashion has partial pressures to transmit directly for component bottom surface), has the eccentric compression function in the component, this function has overcome the bending moment which outside the part the load produces, reduced outside the load effect, thus sharpened component's anti-curved ability. At the same time, because the tension bar passes to component's pressure function, the component crack development can alleviate, the control, the oblique section anti-to cut the supporting capacity also along with it enhancement.As a result of the horizontal lifting stem's function, the original component's section stress characteristic by received bends turned the eccentric compression, therefore, after the reinforcement, component's supporting capacity was mainly decided in bends under the condition the original component's supporting capacity 。
本科毕业设计(论文)翻译-BSt 500s 钢筋抗腐蚀性能研究
本科毕业设计（论文）翻译英文原文名Tensile behavior of corrodedreinforcing steel bars BSt 500s 中文译名BSt 500s 钢筋抗腐蚀性能研究班级姓名学号指导教师填表日期英文原文版出处：EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS译文成绩：指导教师签名：原文：1. IntroductionSteel bars in reinforced concrete carry mainly tension loads. According to the present day standards, e.g. [1], for involving reinforcing steel in concrete structures, certain minimum values for the mechanical properties modulus of elasticity (E), yield stress (R p), ultimate stress (R m) and elongation to failure (f u) of the steel are required. Furthermore, the standard sets R m/R p > 1.05 [1].With increasing service life of a reinforced concrete structure damage accumulates gradually. Nowadays, significant resources are allocated worldwide for the repair and rehabilitation of deteriorating concrete structures. Recent reports indicate that the annual repair costs for the reinforced concrete structures of the network of highways in the USA alone amounts to 20 billion USD [2]. The respective repair costs for reinforced concrete bridges in England and Wales amount to 615 million GBP [3]. Yet, although in recent years the problem of the actual residual strength degradation of ageing reinforced concrete structures has attracted considerable attention, it is far from being fully understood and, even less, resolved. It is worth noting that up to now, little work has been done to account for the effects of corrosion on the mechanical properties of the reinforcing steel bars and hence on the degradation of the load bearing ability of a reinforced concrete element [4]. Such effects are the reduction of the effective cross-section of the reinforcing steel, micro and macro cracking of concrete and finally the spalling of the concrete.The underestimation of the corrosion problem arises from the fact that under normal circumstances, concrete provides protection to the reinforcing steel. Physical protection of the reinforcing steel against corrosion is provided by the dense and relatively impermeable structure of concrete. The thin oxide layer covering the reinforcement, during concrete hydration, ensures chemical protection. The oxide layer remains stable in the alkaline concrete environment(pH > 13), but begins to deteriorate when the pH of the pore solution drops below 11 [5] and [6]. The rate of deterioration due to corrosion rises when the pH drops below 9. For corrosion tocommence, the oxide film must be broken or depassivated. Depassivation may occur if the alkalinity of the pore solution in the concrete pores decreases and/or penetration of the chloride ions takes place. This may be caused by carbonation, especially in the proximity of cracks, or by water dilution which accompanies cracking [7], [8] and [9]. The advancing corrosion results in a reduction of the load carrying cross-section of the bars and an increase in their volume, which may cause cracking of concrete as well as an appreciable decrease on the bond strength between the reinforcing bars and concrete [10] and [11].The above considerations do not account for the effect of corrosion on the mechanical behavior of the reinforcing steels. Most of the available studies on the corrosion of reinforcing steels refer to the metallurgical aspects of corrosion such as the mass loss, the depth and the density of pitting etc., e.g. [12] and [13]. It is worth noting that the corroded steel bars are located in a zone of high tensile or shear stresses [5], [12], [14], [15], [16] and [17]. Maslechuddin et al. [10] evaluated the effect of atmospheric corrosion on the mechanical properties of steel bars. They concluded than for a period of 16 months of exposure to atmospheric corrosion, rusting had an insignificant effect on the yield and ultimate tensile strength of the steel bars. Almusallam [18] evaluated the effect of the degree of corrosion of the steel bars in concrete, expressed as percent mass loss, on their mechanical properties. The results of the study indicated a close relationship between the failure characteristics of steel bars and slabs with corroded reinforcement. A sudden failure of slabs in flexure was observed when the degree of reinforcement corrosion expressed as percent mass loss exceeded 13%. The above results on the mechanical behavior of corroded reinforcing steels refer to BSt 420s of DIN 488, (S420s according to the Hellenic standards). The above results clearly indicate the need to account for the effects of corrosion on the mechanical properties of the reinforcing steel BSt 500s (S500s according to the Hellenic standards) which at present is almost exclusively used in reinforced concrete structures. It is worth noting that corrosion damage of the reinforcement, is expected to become more noticeable in new constructions using reinforcing steel S500s, given the fact that this type of steel exhibits greater mass loss due to corrosion compared to steel classes S400 and S220 [19]. Recall that many reinforced concrete structures are located in coastal areas with an intense corrosive environment. On the other hand, a wide spread use of corrosion-resistant steel reinforcing bars should not be expected as these bars cost about six to nine times more than plain carbon steel reinforcing bars.In the present study, the effects of corrosion on the tensile behavior of reinforcing steel bars Class S500s tempcore are investigated. The specimens were pre-corroded using laboratory salt spray tests for different exposure times. The dependencies of the degradation of the tensile properties on the corrosion exposure time have been derived. The tensile properties of thecorroded material were compared against the requirements set in the standard for involving steels in reinforced concrete structures.2. Experimental researchThe experiments were conducted for the steel S500s tempcore, which is similar to the BSt500S steel of DIN 488 part 1 [20]. A stress–strain graph of the uncorroded material is shown in Fig. 1. The chemical composition (maximum allowable % in final product) of the alloy S500s is: C, 0.24%; P, 0.055%; S, 0.055%; N, 0.013% [21].(13K)Fig. 1. Stress–strain graph of uncorroded BSt 500s alloy.The material was produced by a Greek industry by using the tempcore method (hot rolling followed by quenching and self tempering) and was delivered in the form of ribbed bars. The nominal diameter of the bars was 8 mm (Ø8). From the bars, tensile specimens of 230 mm length were cut. The gauge length was 120 mm according to the specification DIN 488 Part 3 [22]. Prior to the tensile tests, the specimens were pre-corroded using accelerated laboratory corrosion tests in salt spray environment.2.1. Salt spray testingSalt spray (fog) tests were conducted according to the ASTM B117-94 specification [23]. For the tests, a special apparatus, model SF 450 made by Cand W. Specialist Equipment Ltd. was used. The salt solution was prepared by dissolving 5 parts by mass of Sodium Chloride (NaCl) into 95 parts of distilled water. The pH of the salt spray solution was such that when dissolved at 35 °C, the solution was in the pH range from 6.5 to 7.2. The pH measurements were made at25 °C. The temperature in the zone of the reinforcement material exposed inside the salt spray chamber was maintained at 35 °C + 1.1–1.7 °C. When exposure was completed, the specimens were washed with clean running water to remove any salt deposits from their surfaces, and thenwere dried. In addition, a number of steel bars of the same length were exposed to the salt spray for 1, 2 and 4 days to monitor the corrosion damage evolution.2.2. Mechanical testing procedureThe pre-corroded specimens were subjected to tensile tests. All mechanical tests are summarized in Table 1.Table 1.Tensile tests for S500s Ø8 tempcore steelThe performed tensile tests aim to provide information on:1. the gradual deterioration of the mechanical properties of the S500s tempcore steel reinforcement during salt spray corrosion;2. whether the exposure of the specimens to salt spray might degrade their tensile property values such that they do no longer meet the limits set by the Hellenic standards for using steel in reinforced concrete structures, e.g. [1] and [24].The tensile tests were performed according to the DIN 488 specification [22]. For the tests a servo-hydraulic MTS 250 KN machine was used. The deformation rate was 2 mm/min. The tensile properties: yield stress R p, ultimate stress R m, elongation to fracture f u and energy density W0 were evaluated. The energy density is calculated from the area under the true stress–true strain curve. In the present work, the energy density has been evaluated from the engineering stress–engineering strain curves as(1)as an engineering approximation.3. Results and discussionAs expected, corrosion damage increases with increasing exposure time to salt spray. The exposure of the specimens to the salt spray environment causes the production of an oxide layer which covers the specimen and increases in thickness with increasing exposure time of the specimen. Removal of the oxide layer by using a bristle brush according to the ASTM G1-90 [25] specification has shown extensive pitting of the specimens already after 10 days of exposure to salt spray. The stereoscopic image of a specimen after exposure to salt spray for 10 days is shown in Fig. 2. It is compared against the image of the uncorroded material. It was observed that the corrosion attack started at the rib roots and advanced towards the area between the ribs. The indentations of the corrosion attack left on the specimen surface after removal of the oxide layer increase in dimensions and depth with increasing duration of the exposure.(84K)Fig. 2. Stereoscopic images (×35) of (a) uncorroded specimen and (b) specimen exposed to salt spray corrosion for 10 days.The production of the oxide layer is associated to an appreciable loss of the specimen’s mass. The dependency of the obtained mass loss on the salt spray duration is displayed in Fig. 3. The derived dependency may be fitted by the Weibull function(2)The determined Weibull values C1 to C4 are given in Table 2. As it can be seen for salt spray duration of 90 days the mass loss of the corroded specimen is about 35% of the mass of the uncorroded specimen. It is worth noting that the involved salt spray test is an accelerated corrosion test which is performed at the laboratory. Although the salt spray test environment, to some extent, simulates qualitatively the natural corrosion in coastal environment, it is much more aggressive and causes a very severe corrosion attack in a short time. Currently, there is no direct correlation between the accelerated laboratory salt spray test and the natural corrosion of reinforcing steels such as to assess a realistic duration for the accelerated laboratory salt spray tests. Fig. 4 shows a photograph taken from a building constructed in 1978 at a coastal site in Greece. The corroded reinforcing bars indicated a severe mass loss. The mass loss of the corroded bars shown in Fig. 4 was as high as 18% which corresponds to an exposure of 44.5 days according to the fitting curve in Fig. 3. The corrosion measured for the mentioned case appeared rather frequently during an extensive investigation on the integrity of older constructions at coastal sites in Greece. Even though the above results are by far not sufficient for establishing exact correlations between laboratory salt spray tests and natural corrosion, they clearly indicate that laboratory salt spray exposures for 40 days and longer are realistic for simulating the natural corrosion damage of steel bars which might accumulate during the service time of reinforced concrete structures at coastal sites. By assuming a uniform production of the oxide layer around the specimen and hence a uniform mass loss, the results of Fig. 3 can be exploited to calculate the reduction of the nominal specimen diameter with increasing duration of the salt spray test. The reduced diameter d r is calculated as(3) where a is the measured mass loss in percent and d is the nominal diameter of the uncorroded specimens (8 mm).The reduced values for the nominal specimen diameter are given in Table 3. The reduction specimen diameter with increasing salt spray exposure time is displayed in Fig. 5. The results in Fig. 5 were fitted using Eq. (2). The Weibull values C1 to C4 for Fig. 5 are given in Table 2.(18K)Fig. 3. Effect of the duration of corrosion exposure on mass loss.Table 2.Weibull valuesMass loss DiameterreductionYield stressreductionUltimate stressreductionEnergydensityElongation tofailureC166.09119 6.48612282.22252373.991435.1901 6.69354 C2100.240198.01075559.44776649.74026122.6928218.81317 C3 1.70934 1.73042 1.65825 1.64161 1.54774 1.60975 C47.195497.22599.770719.41832 3.85845 3.94068(98K)Fig. 4. Photograph taken from building constructed in 1978.Table 3.Values of reduced specimen diameter(18K)Fig. 5. Reduction of specimen’s diameter with increasing duration of corrosion exposure.It is essential to notice that the strength calculation of steel reinforced concrete structures according to the standards, e.g. [24], occurs by using an engineering stress estimated by assuming the cross-sectional area as(4)with d being the nominal diameter of the bars. For the bars of the present study, the nominal diameter was 8 mm. According to the valid standards, there is no special consideration for the reduction of the nominal diameter of the reinforcing steel, even when evaluating the strength of an older reinforced concrete structure indicating a severe corrosion damage of the reinforcing bars as shown in Fig. 4. Displayed in Fig. 6 and Fig. 7 are the apparent values of the engineering yield stress and ultimate stress over the duration of salt spray exposure by neglecting the reduction of the cross-section of the corroded specimens. In Fig. 6 and Fig. 7, the above values are referred to as R papp and R mapp, respectively. The results have been fitted using the Weibull function of Eq. (2). The Weibull constants C1 to C4 for Fig. 6 and Fig. 7 are given in Table 2. As shown in the figures, the apparent values of R m and R p drop below the limits of R m = 550 MPa for ultimate stress and R p = 500 MPa for the yield stress, which are set by the standards [21] for involving reinforcing steels, after 32 and 27 days exposure to salt spray, respectively. Yet, the obtained degradation of the apparent strength values of the material reflects not only the effectof corrosion on the mechanical properties of the material but also a stress increase due to the reduction of the specimen’s cross-section. The effect of corrosion on the tensile strength properties of the reinforcing steel can be assessed when removing from the surface of the bars the corrosion products and also using in the calculation of the engineering stress the reduced nominal specimen diameters which are given in Table 3. The measured strength values are given in Table 4 and in the following will be referred to as R peff and R meff, respectively. For the uncorroded material, the effective strength values have been calculated by using the truecross-sectional area: [22](5)where G is the weight and l is the length of the specimen, whereas for the apparent strength values, the cross-sectional area was calculated by using Eq. (4). The dependencies of the effective engineering yield and ultimate stress on the duration of salt spray exposure are displayed in Fig. 6 and Fig. 7 as well. As it can be seen in the figures, the corrosion attack causes a moderate tensile strength reduction which increases with increasing duration of the corrosion exposure, even though for the calculation, the reduced nominal specimen diameters have been used. This result is consistent to the observation of the performed corrosion characterization. It should be remembered that the indentations of the corrosion attack that remained on the specimen surface after removal of the oxide layer and hence, the associated notch effects during tensile loading were found to increase in dimensions and depth with increasing duration of the exposure. Furthermore, as corrosion attacks the surface of the bars, the specimen cross-section which is reduced by corrosion damage refers to material rich in high strength martensite. The experimentally observed reduction of yield and ultimate stress with increasing time of corrosion exposure can be fitted by the set of equations:R p(t)=A1+B1t+B2t2(6) andR m(t)=A2+B3t+B4t2. (7) The constants A1, B1, B2, A2, B3 and B4 in Eqs. (6) and (7)were derived to 596.19291, −2.59222, 0.00563, 695.67537, −2.92755 an d 0.01375, respectively.(23K)Fig. 6. Effect of the duration of corrosion exposure on yield strength.(23K)Fig. 7. Effect of the duration of corrosion exposure on ultimate stress.Table 4.Mechanical property degradation during salt spray corrosionEven though the actual effect of corrosion on the tensile engineering strength properties of the reinforcing steel is moderate, the corrosion damage problem for the integrity of an older reinforced concrete structure remains significant. It is noticeable that the effective engineering strength of the corroded specimens R meff drops below the limit set by the standards as the minimum requirement for the stress value at about 40 days salt spray corrosion exposure. As it is shown in Fig. 8, it represents a corrosion damage situation which is not unrealistic for older buildings. Furthermore, as the loads of a reinforced concrete structure remain the same during the service time of the structure, the reduction of the load carrying cross-section of the bars due to corrosion damage results to an increase of the stress applied to the bars. By considering Eqs.(3) and (4), the values of the applied stress on the reinforcing bars can be calculated as(8)with σ0 being the applied stress for the uncorroded material. For the case under consideration, it refers to a bar with d0 = 8 mm. An example of the increase on applied stress as a result of the reduction of the load carrying cross-section with increasing duration of the salt spray exposure is shown in Fig. 8. The values taken for σ0 for the two curves in Fig. 8 were 280 and 320 MPa, respectively. The synergistic effect of the observed decrease on the effective strength values of the material and the increase of applied stresses due to the cross-section reduction may reduce appreciably the safety factors involved in the calculations of a reinforced concrete structure. Note that the safety factor normally used when designing reinforced concrete structures is 1.5. Furthermore, it should be noted that the reduction of the cross-section of a reinforcing bar also reduces the moment of inertia of the steel bar.(22K)Fig. 8. Applied stress increase as a function of the duration of corrosion exposure.The effects of increasing corrosion damage on the tensile ductility of the investigated steel bars are shown in Fig. 9 and Fig. 10. Both elongation to fracture, Fig. 9, and energy density, Fig. 10, decrease appreciably with increasing duration of the salt spray exposure. The value of elongation to fracture meets the requirement f12%, as requested by the standards in [1], forexposures to salt spray of up to 35 days. As discussed above, the corrosion damage referring to 35 days laboratory salt spray exposure is not unrealistic for corroded reinforcing steels of older buildings at coastal sites. Fig. 9 and Fig. 10 have been approximately fitted using the Weibull function. The Weibull constants C1 to C4 are given in Table 2.(19K)Fig. 9. Effect of the duration of corrosion exposure on elongation to fracture.(16K)Fig. 10. Effect of the duration of corrosion exposure on energy density.The standards do not require for the evaluation of the energy density W of the reinforcing steel. Energy density is a material property which characterizes the damage tolerance potential of a material and may be used to evaluate the material fracture under both, static and fatigue loading conditions [26]. Note that energy density may be directly related to the plain strain fracture toughness value, K IC, e.g. [27], which evaluates the fracture of a cracked member under plain strain loading conditions.The observed appreciable reduction on tensile ductility may represent a serious problem for the safety of constructions in seismically active areas. As during the seismic erection, the reinforcement is often subjected to stress events at the region of low cycle fatigue, the need for a sufficient storage capacity of the material is imperative.4. Conclusions• The exposure of the steel bars S500s tempcore to salt spray environment results to an appreciable mass loss which increases with increasing duration of exposure. Durations of laboratory salt spray exposures of 40 days or longer are realistic for simulating natural corrosion damage obtained at members of old buildings at coastal sites.• The effect of salt spray exposure on the strength properties of the steel S500s is moderate. Yet, with regard to the observed appreciable mass loss, the increase on the effective engineering stress is essential such as to spend the reserves on strength which are required in the standards trough safety factors.• The effect of salt spray exposure on the tensile ductility of the material is appreciable. For salt spray exposures longer than 35 days, elongation to fracture drops to values lying below thef u = 12% limit which is required in the standards.• Present day standards for calculating strength of reinforced concrete members do not account for the appreciable property degradation of the reinforcing steel bars due to the gradually accumulating corrosion damage. Although, a revision of the standards such as to account for the above corrosion effects on the material properties seems to be required, further extensive investigation is needed to conclude on proper recommendations for such a revision.References[1] Hellenic Regulation for the Technology of Steel in Reinforced Concrete; no.Δ14/36010-29.2/24.3.2000 (Government Gazette Issue) 381B.[2] Strategic High Research Program. Concrete and Structures; Progress and Product Update. Washington, DC: National Research Council; 1989.[3] E.J. Wallbank, The performance of concrete in bridges, HMSO, London (1989).[4] D.G. Manning, Design life of concrete highway structures – The North American scene, Design Life Struct (1992), pp. 144–153.[5] J.P. Broomfield, Corrosion of steel in concrete, E & FN Spon, London (1997) p. 22.[6] Papadakis VG. Supplementary cementing materials in concrete – activity, durability and planning. Danish Technological Institute Concrete Center, January; 1999.[7] Roberto Capozucca, Damage to reinforcement concrete due to reinforcement corrosion, Construct Build Mater9 (1995) (5), pp. 295–303.[8] S.E. Diamond, Chloride concentrations in concrete pore solutions resulting from calcium and sodium chloride admixtures, Cement Concrete Aggr8 (1986) (2), pp. 97–102.[9] M.G. Alvarez and J.R. Galvele, The mechanisms of pitting of high purity iron in Nacl solutions, Corros Sci24 (1984), pp. 27–48.[10] M. Maslehuddin, I.M. Ibrahim, Huseyin Saricimen and Abdulaziz l. Al-Mana, Influence of atmospheric corrosion on the mechanical properties of reinforcing steel, Construct Build Mater8 (1993) (1), pp. 35–41.[11] Congqi Fang, Karin Lundgren, Liuguo Chen and Chaoying Zhu, Corrosion influence on bond in reinforced concrete, Cement Concrete Res (2004).[12] Borgard B, Warren C, Somayaji S, Heidersbach R. Mechanisms of corrosion of steel in concrete. ASTM STP 1065, Philadelphia; 1990. p. 174.[13] M.D.A. Thomas and J.D. Mathews, Performance of pfa concrete in a marine environment –10-year results, Cement Concrete Compos26 (2004), pp. 5–20.[14] T. Yonezawa, V. Ashworth and R.P.M. Procter, Pore solution composition and chloride effects on the corrosion of steel in concrete, Corrosion44 (1988), pp. 489–499.[15] M.F. Montemor, A.M.P. Simoes and M.M. Salta, Effect of fly ash on concrete reinforcement corrosion studied by EIS, Cement Concrete Compos22 (2000), pp. 175–185.[16] B. Elsener, Macrocell corrosion of steel in concrete – implications for corrosion monitoring, Cement Concrete Compos24 (2002), pp. 65–72.[17] C. Arya and P.R.W. Vassie, Influence of cathode-to-anode area ratio separation distance on galvanic corrosion currents of steel in concrete containing chlorides, Cement Concrete Res25 (1995), pp. 989–998.[18] A.A. Almusallam, Effect of degree of corrosion on the properties of reinforcing steel bars, Construct Build Mater15 (2001) (8), pp. 361–368.[19] Mpatis G, Rakanta E, Tsampras L, Mouyiakos S, Agnantiari G. Corrosion of steel used in concrete reinforcement, in various corrosive environments, Technical Chamber of Greece, 13th Hellenic Convention for Concrete. vol. II, Rethymnon, Crete; 1999. p. 497–505.[20] DIN 488-1, Reinforcing steel grades, properties, marking; 1986.[21] ELOT 971, Hellenic standard, weldable steels for the reinforcement of concrete,1994-04-01.[22] DIN 488-3, Reinforcing steel bars testing; 1986.[23] ASTM B 117-94, Standard practice for operating salt (fog) testing apparatus. In: Annual book of ASTM standards, section 3, Metal test methods and analytical procedures, West Conshohocken, ASTM, Philadelphia, USA; 1995. p. 1–8.[24] Hellenic Anti-Seismic Code 2000 (EAK 2000).[25] ASTM G1 – 90, Standard practice for preparing, cleaning, and evaluating corrosion test specimens.[26] G.C. Sih and C.K. Chao, Failure initiation in unnotched specimens subjected to monotonic and loading, Theor Appl Fract Mech2 (1984), pp. 67–73.[27] D.Y. Jeong, O. Orringen and G.C. Sih, Strain energy density approach to stable crack extension under net section yielding of aircraft fuselage, Theor Appl Fract Mech22 (1995), pp. 127–137.译文：BSt 500s钢筋抗腐蚀性能研究1. 前言在钢筋混凝土中钢筋主要承受拉力. 根据今天的标准,例如[1]、对涉及钢筋混凝土结构、最小弹性模量(E)、屈服强度(Rp),极限压力(Rm)和钢筋的塑性(fu)等是必要的. 此外,这个标准规定Rm/Rp > 1.05 [1].在日益钢筋水泥结构的寿命逐渐累积损失. 目前,全世界的重要资源分配修复混凝土结构恶化. 最近的报告显示,每年的维修费钢筋混凝土结构的公路网,仅相当于美国的20亿美元[2]. 有关钢筋混凝土桥梁维修费英格兰和威尔士6.15亿英镑等于[3]. 然而,尽管近年来实际问题残余力量钢筋混凝土结构老化退化,引起相当大的注意,但还远没有充分了解,更不用说解决. 值得注意的是,到现在为止,没有进行过工作,占侵蚀影响的机械性能加固钢筋,所以就退化的承载能力的钢筋混凝土部分[4]. 这些都影响了有效降低截面的钢筋、混凝土的微观和宏观裂缝和最后的水泥剥落.被低估的腐蚀问题的出现,是因为在正常情况下,具体规定了保护钢筋. 对人身保护的钢筋腐蚀提供了较为稠密,不透水的混凝土结构. 薄的氧化层复盖加固,在具体水化、化学防护保障. 在保持稳定的碱性氧化物层的具体环境(酸碱度"13),而开始恶化时的孔隙荣获解决少于11 [5]和[6].由于故障率低于酸碱腐蚀时上涨9. 开始的腐蚀,氧化或depassivated电影必须打破. 如果碱度depassivation可能发生的孔隙减少毛细孔的具体办法和/或氯离子渗透的发生. 这可能是造成碳化,特别是在靠近裂缝,伴随水稀释的作用产生裂缝[7], [8]和[9].进一步腐蚀造成的削减负荷截面酒吧和增加其数量,这可能造成的裂痕,以及具体明显下降的债券之间的实力和钢筋混凝土[10]和[11].上述因素的影响,还不是在腐蚀钢筋钢机械行为. 现有的大部分研究腐蚀钢指加强冶金等方面的腐蚀重量损失、深度和密度等对立,例如[12]和[13].值得指出的是,钢筋腐蚀区位于高张力、剪压[5], [12], [14], [15], [16]和[17].AlMaslechuddin网站. 10影响评价的大气腐蚀钢筋机械性能. 他们不是结束,为期16个月,受大气腐蚀、锈蚀所产生的影响是微不足道的,最终钢筋的抗拉强度. Almusallam18度影响评估的钢筋混凝土腐蚀、重量损失%表示,他们的机械特性. 研究结果表明两者之间的关系非常密切,没有特色,砖、钢筋腐蚀钢筋. 突然失败砖flexure在观察时表示腐蚀程度增加重量损失超过13%左右. 上述成果的巩固腐蚀钢机械行为是指自家人打自家人的420s牛488(s420s根据希腊的标准). 以上结果清楚地表明,必须占侵蚀影响的机械特性的钢筋牛500s(s500s根据希腊的标准),目前几乎全部采用钢筋混凝土结构. 值得注意的是,腐蚀破坏的钢筋,今后将更加明显,新的建筑用钢筋s500s,因为这种钢展品体积更大损失侵蚀而钢班和S400S22019. 记得许多钢筋混凝土建筑物位于沿海地区有强烈腐蚀性的环境. 另一方面,腐蚀了广泛使用抗钢筋不应指望这些酒吧约需六至九倍多平原碳钢筋.在本次研究的张力行为的影响腐蚀钢筋强化班S500sTempcore调查. 物种是前盐腐蚀喷射实验室用不同曝光时间进行测试. 退化的附庸张力财产所得的曝光时间腐蚀. 张力腐蚀材料性能的要求,而对标准涉及的钢筋混凝土结构钢.2. 实验研究他的实验进行钢TempcoreS500s,类似于Bst500s钢的一部分148820自家人打自家人. 一紧张压力的图表显示模型uncorroded材料. 1. 化学成份(最大可成最终产品)的合金s500s 是: C, 0.24%; P, 0.055%; S, 0.055%; N, 0.013% [21].图1. BSt 500s 新合金压力曲线物质是由希腊工业用Tempcore方法(冷、热轧自我锻炼之后),是以网吧玩. 名义上是直径8毫米酒吧(ø8). 从酒吧、张力标本230毫米长度削减. 长度是120毫米的各种规格按4883部分Din22. 张力测试之前,样本是前使用加速腐蚀试验的腐蚀盐喷实验环境.210. 盐喷射测试盐米(雾)据测试,ASTMB117-9423规格. 为测试、特殊仪器、450名模范奥委会提出cand设备有限公司是专门用于W. 盐水的解散是由5部分群众的氯化钠(NACL)95个地区为蒸馏水. <宋庆龄的解决办法是用这种盐,当在350C解散,由宋庆龄在解决6.5to7.2. 测量水的比重均在25C. 高温区加固材料暴露在盐米保持在350C厅+1.1-1.7℃C. 当暴露结束后,样品是自来水冲洗干净,以消除其表面的盐矿床,然后被干. 此外,一些同样长的钢筋受到盐的使用1、2、4天监测腐蚀损坏演变.22. 机械测试程序前张力遭到腐蚀试验样品. 所有机械试验见表1.表1.。
毕业论文外文翻译--葡萄牙的钢结构发展——帕特里克道林的影响
附件1：外文资料翻译译文摘要：本文基于大学教研和葡萄牙协会对钢结构和复合结构的创造，主要讲述了帕特里克道林教授对作者职业生涯和葡萄牙钢结构发展的影响。
关键词：葡萄牙；钢；结构；研究1.导言截至钢筋混凝土的出现和第一次世界大战的到来，在钢铁的应用方面葡萄牙紧随欧洲大多数国家的脚步。
此后，铸造厂虽然存在，但是为了保护葡萄牙和其殖民地的正在发展中的水泥业，葡萄牙在进口结构产品方面收取很高的税收。
第一钢铁厂坐落在赛沙尔，建于1961年，横跨了起源与里斯本的河流并从安哥拉获取铁矿石和煤炭，但是这项大的投资并没有制止结构钢的使用下降，然而由于这家工厂主要生产工业建筑用钢以及轧制小型材，结构钢的使用下降几乎限制了建筑行业的发展。
钢结构规范反映了这一衰退，而且直至的19世纪80年代葡萄牙一直使用着过时的规范。
确切的说，大学中对钢结构研究和教学的缺失是导致结构钢使用量下降的原因之一，而结构钢使用量下降加剧了这一恶性循环。
在混凝土行业情况大为不同，在这个领域，葡萄牙的土木工程国家实验室(LNEC)是世界领先机构，而且葡萄牙市行政首长协调会和编写混凝土规范的积极参与者。
葡萄牙地处地震风险区，国家实验室在混凝土结构抗震性方面做的研究和先进规范的适用性都给予混凝土行业以信心和优势。
因此所有土木工程课程都把重点放在了混凝土的教学上，而忽略了钢结构和复合结构的教学。
在1974年民主革命的几年前，土木工程行业发生了一次深刻的教育系统的变革。
一个培养新型研究人员的大型机构成立了，这一机构专门培养没有被各大学和公共实验室涵盖的研究人员并提供出国学习的资金。
里斯本技术大学工程学院是一高级技术研究所（IST），它是最早受益于这一大型机构的机构之一，并且钢结构被明智地确定为土木工程学院新型职工培训的主要要求。
由于正在进行的殖民战争，我在刚刚服完长期的兵役之后，获得了一笔助学金是我可以在皇家学院学习钢结构课程。
我在大学期间接受的建筑结构方面的培训是很充分的，但是正是由于几何非线性和材料非线性与混凝土结构联系不大，大学的教学在这两方面是不足的。
钢结构毕业设计计算书
毕业设计（论文）题目：某五层钢框架公寓楼结构设计Tittle: Steel Frame of A Five-story Apartment Building Structural Design学生姓名专业名称指导教师前言本次毕业设计是大学教育培养目标实现的重要步骤，是毕业前的综合学习阶段，是深化、拓宽、综合教学成果的重要过程，是对大学期间所学专业知识的全面总结。
本次设计使理论和实际很好的结合起来，提高了分析、解决工程实际问题的能力。
培养了学生严谨、求实、细致、认真和吃苦耐劳的工作作风。
为以后更好的学习和工作奠定了坚实的基础。
在毕业设计期间，我重新复习了《房屋建筑学》、《钢结构》、《结构力学》、《建筑结构抗震设计》等课本知识，并查阅了《抗震规范》、《钢结构规范》、《荷载规范》等相关规范。
在毕业设计过程中，我们通过所学的基本理论、专业知识和基本技能进行了建筑、结构的具体设计。
现在毕业设计任务已圆满完成。
在此，对校领导、老师及在此期间关心我帮助我的所有同学们表示衷心的感谢。
本设计包括建筑设计和结构设计两大部分，叙述内容包括设计原理、方法、规范、规章、设计技术要求和计算表格。
其中，建筑设计部分由平面设计、立面设计、功能分区、采光和防火安全的要求等部分组成；结构部分由荷载计算、内力分析、内力组合、节点和柱脚设计等部分组成。
毕业设计的三个月里，在指导老师的帮助下，经过资料查阅、设计计算、论文撰写以及外文的翻译，加深了对新规范、规程、手册等相关内容的理解。
巩固了专业知识、提高了综合分析、解决问题的能力。
在绘图时熟练掌握了天正建筑、AutoCAD、PKPM等建筑软件，这些都从不同方面达到了毕业设计的目的与要求，巩固了所学知识。
目录摘要 (1)Abstract (2)第1章建筑设计 (3)1.1 工程概况 (3)1.1.1 建筑概况 (3)1.1.2 工程地质条件 (3)1.1.3 气象条件 (4)1.2 平面设计 (5)1.3 立面设计 (5)1.4 细部做法 (6)1.4.1 楼面做法（楼面详图如图1.8.1） (6)1.4.2 屋面做法（屋面详图如图1.8.2） (6)1.5 材料选择 (7)1.5.1 梁柱材料 (7)1.5.2 墙体材料 (7)1.5.3 楼梯材料 (7)1.5.4 楼（屋）板材料 (7)第2章结构设计 (8)2.1 工程概况及设计参数 (8)2.2 结构布置及计算简图 (8)2.2.1 计算单元 (8)2.2.2 构件截面尺寸初选 (8)2.2.3 框架计算简图 (10)2.3 荷载计算及其内力分析 (11)2.3.1 荷载计算 (11)2.3.2 荷载作用分布图 (13)2.3.3 荷载内力分析 (17)2.4 内力组合 (29)2.4.1 框架梁内力组合 (29)2.4.2 框架柱内力组合 (34)2.5结构、构件验算 (34)2.5.1框架柱验算 (34)2.5.2 框架横梁验算 (43)2.5.3 次梁验算 (46)2.6 组合楼盖设计 (49)2.6.1 楼板设计 (49)2.6.2 屋面板设计 (53)2.7 框架连接设计 (57)2.7.1 主梁与柱的连接设计 (57)2.7.2 次梁与主梁的连接设计 (68)2.7.3 柱脚设计 (71)2.8 基础设计 (78)2.8.1 A柱基础设计 (78)2.8.2 B柱基础设计 (83)总结 (87)致谢 (88)参考文献 (89)摘要：本文的毕业设计主要讲述了办公楼设计。
钢结构毕业论文最终版
毕业论文论文题目：浅谈钢结构专业：建筑工程技术班级：学号：姓名：浅谈钢结构引言老师您好，我是，这次写的论文是浅谈钢结构。
现在建筑行业的发展，对钢结构所建筑的房屋越来越需要，由于钢结构自身的优点突出，目前在国内得到越来越广泛的应用。
随着国内经济的发展和改革开放的深入，国内钢材每年的产量已连续超过100.000.000t，成为世界第一，迅速增长的钢材产量为发展国内钢结构建筑创造了优越的条件。
正文钢结构建筑具有高强轻质、抗震性能好、力学性能优越、施工迅速、工业化程度高、外观优美、可多次利用并且符合国家可持续发展的政策等一系列优点，近几年钢结构建筑在国内发展的很迅速，应用范围不断扩大，但与国外一些发达国家相比，还有一定的差距。
本文结合现实生活，浅谈了一些在建筑施工过程中的一些应用情况，分析了钢结构迅速发展的一些原因。
钢结构是用钢板，型钢和圆钢等通过焊接，铆接，螺栓连接等方式制造的结构。
与其他结构比较，钢结构有如下一些特点：1 强度高，塑性和韧性都比较好；2 耐火性差。
钢结构的使用范围，是根据上述特点而确定的。
当前在大跨度结构，重工业厂房，高层建筑，高耸结构，容器和其他构筑物，移动结构等方面，多采用钢结构。
钢结构单层工业厂房是工业与民用建筑中应用钢结构较多的建筑物，厂房结构是由房盖，屋面板，檩条，天窗屋架或梁，托架，柱，吊车梁（包括制动梁或制动桁架），墙架，各种支撑和基础等构件组合而成的空间刚性骨架，承重作用下在厂房结构上的各种荷载，是整个建筑物的承重骨干。
在单层厂房钢结构中，通常由许多平行等间距放量的横向平面框架作为基本承重结构。
横向平面框架由柱和梁组成。
柱在基础处通常做成固定端横梁与柱的连接可以做成铰接。
但为了增加刚度和节约钢材，通常做成刚接，则构成横向平面刚架包括全部建筑物重量（屋盖，墙，结构自重等）屋面雪荷载和积灰荷载和其他活荷载，吊车竖向荷载和横向水平制动力，横向风荷载，横向地震作用等。
横梁通常是桁架式的（即屋架）轻屋面和跨度小时也可采用实腹式的。
钢结构毕业设计之英文翻译
形成这些应力的主要原因被是支撑的中间板以及约束面内弯曲的加劲肋焊缝在长度方向上的收缩，如图10。
Â。
类似于垂直残余应力的分布，观察前面对焊试件[2]。
这些应力明显也呈现在上下扁杆的开始位置（如图2）这意味着，这种残余应力是系统发生的，其中平面内弯曲由于焊缝收缩受到抑制。
有趣的是，两个一个焊脚是在压缩，而另一个是在张力下。
对于中间板的纵向加劲肋后者是容易产生疲劳破坏，，这是众所周知的情况，在下一节会提到。
纯压应力下的疲劳失效的例子第二个例子是关于周期性压应力下的疲劳失效，它可以发生在高拉伸残余应力区，如前面的纵向加劲肋筋。
因此，选试样的[纵向加强筋11，12]来对这个问题进行深入研究，归纳如下。
图11显示出了试样的细节，由钢制成，屈服强度为355 MPa 角焊缝制作成两层，产生一个充分发展的残余应力场。
通过加载周期性脉冲来进行恒定振幅疲劳试验。
应力上限设置为零。
I，Ë。
R =-1。
选定两个应力范围，dr=140兆帕和180兆帕。
图12显示出了在较低的负载水平的板表面上的裂缝的发展。
早期裂纹萌生后，裂纹扩展速率增加，直到超出总裂纹长度约50毫米出现减速。
这是由于裂纹闭合效应，几乎停止后裂纹长度已经达到85 - 95毫米。
假设失效的标准的裂纹长度为80mm。
由此产生的疲劳寿命被绘制在图中。
13从统计评估中得到不同的完好概率的PS。
在106个循环（83兆帕）的疲劳强度几乎比早期脉冲拉伸荷载疲劳试验（71兆帕）高20％，这表明在负载R的影响下，残余应力对（a）裂缝的产生及（b）纯压缩载荷下的裂缝发展发挥作用。
为了更深入地了解焊接残余应力及其在循环加载过程中的重新分配，应用有限元分析，进行了测量[11]。
图14示出了两个有限元模型一起在第一遍焊接数控模拟得到的在长度方向的焊接引起的残余应力。
左边的图显示四分之一体元素为建模试件。
前面的加劲肋高的拉伸残余应力，可以很好地确认。
由于受力平衡，在横向截面AA，残余应力变化的中心等于外板受拉伸压缩的面积实体模型也被用来进行早期裂纹扩展过程中的应力分析，其中一个半椭圆形的裂纹发展的临街为穿过焊脚。
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浅谈钢结构现在，钢以一种或者形式逐渐成为全球应用最广泛的建筑材料。
对于建筑构架，除了很特殊的工程之外，钢材几乎已经完全取代了木材，总的来说，对于桥梁和结构骨架，钢也逐渐代替了铸铁和炼铁。
最为现代最重要的建筑材料，钢是在19世纪被引入到建筑中的，钢实质上是铁和少量碳的合金，一直要通过费力的过程被制造，所以那时的钢仅仅被用在一些特殊用途，例如制造剑刃。
1856年贝塞麦炼钢发发明以来，刚才能以低价大量获得。
刚最显著的特点就是它的抗拉强度，也就是说，当作用在刚上的荷载小于其抗拉强度荷载时，刚不会失去它的强度，正如我们所看到的，而该荷载足以将其他材料都拉断。
新的合金又进一步加强了钢的强度，与此同时，也消除了一些它的缺陷，比如疲劳破坏。
钢作为建筑材料有很多优点。
在结构中使用的钢材成为低碳钢。
与铸铁相比，它更有弹性。
除非达到弹性极限，一旦巴赫在曲调，它就会恢复原状。
即使荷载超出弹性和在很多，低碳钢也只是屈服，而不会直接断裂。
然而铸铁虽然强度较高，却非常脆，如果超负荷，就会没有征兆的突然断裂。
钢在拉力（拉伸）和压力作用下同样具有高强度这是钢优于以前其他结构金属以及砌砖工程、砖石结构、混凝土或木材等建筑材料的优点，这些材料虽然抗压，但却不抗拉。
因此，钢筋被用于制造钢筋混凝土——混凝土抵抗压力，钢筋抵抗拉力。
在钢筋框架建筑中，用来支撑楼板和墙的水平梁也是靠竖向钢柱支撑，通常叫做支柱，除了最底层的楼板是靠地基支撑以外，整个结构的负荷都是通过支柱传送到地基上。
平屋面的构造方式和楼板相同，而坡屋顶是靠中空的钢制个构架，又成为三角形桁架，或者钢制斜掾支撑。
一座建筑物的钢构架设计是从屋顶向下进行的。
所有的荷载，不管是恒荷载还是活荷载（包括风荷载），都要按照连续水平面进行计算，直到每一根柱的荷载确定下来，并相应的对基础进行设计。
利用这些信息，结构设计师算出整个结构需要的钢构件的规格、形状，以及连接细节。
对于屋顶桁架和格构梁，设计师利用“三角剖分”的方法，因为三角形是唯一的固有刚度的结构。
因此，格构框架几乎都是有一系列三角形组成。
钢结构可以分成三大类：一是框架结构。
其构件包括抗拉构件、梁构件、柱构件，以及压弯构件；二是壳体结构。
其中主要是轴向应力；三是悬挂结构。
其中轴向拉应力是最主要的受力体系。
网架结构这是刚结构最典型的一种。
多层建筑通常包括梁和柱，一般是刚性连接或是简单的通过沿着提供稳定性的斜向支撑方向在端部连接。
尽管多层建筑是三维的，但通常某个方向即某一维度要比其他维度刚度更大，所以，其有理由被当做是一系列的平面框架。
然而，如果一个框架中某一平面上的构建的特性可以影响其他平面的特性，这个框架就必须当做一个三维框架来考虑。
网壳结构在这类结构中，壳体除了参与传递荷载外，还有其他实用功能。
许多壳体结构中，框架结构也会与壳体一起组合使用。
再强和平屋顶上“外壳”构件也和框架结构一起承担压力。
悬挂结构在悬挂结构中，张拉索是主要的受力构件。
屋面也可以有索支撑。
这种形式的结构主要是吊桥。
这种结构的子系统，是有框架结构组成，就像加劲桁架支撑索桥。
由于这种张拉构建能够最有效的承担荷载，结构中的这种设计理念被越来越广泛的应用。
很多不寻常的结构，是由框架、壳体以及悬挂结构的不同组合形式建造。
在美国，钢结构的设计主要依据是美国钢结构协会颁布的规范。
这些规范是很多学者和一线工程师的经验所得。
这些研究成果被综合处理成一套既安全又经济的设计理念的设计程序。
设计过程中数字计算机的出现促使更加精妙可行的设计规则产生。
规范包括一系列保证安全性的规则，尽管如此，设计者必须理解规则的适用性，否则，很可能导致荒谬的、非常不经济的、有时甚至是不安全的设计结果。
建筑规则有时等同于规范。
这些规则涉及所有有关安全性的方面，例如结构设计、建筑细节、防火、暖气和空调、管路系统、卫生系统以及照明系统。
结构和结构构件必须具有足够的强度、刚度、韧性，以在结构的使用中充分发挥其功能。
设计必须提供足够的强度储备，以承当使用期间的荷载，也就是说，建筑物不需承担可能的超负荷。
改变某一结构原来的使用用途，或者由于在结构分析中采用了过度简化的方法而低估了荷载作用，以及施工程序的变更会造成结构的超载。
即使在允许范围内，构建尺寸的偏差也可导致某个构件低于他所计算的强度。
不管采用哪些设计原理，结构设计必须提供足够的安全性。
必需预防超负荷和强度的不足情况。
在过去的三十年里，如何保证设计安全性的研究一直在继续。
使用各种不同的概率方法来研究构件、连接件或者系统的失效可能性。
此外，由于结构钢构件相当高的造价，与人工安装费用相比，材料采购成本是巨大的。
与其他总承包合同中所涉及的混凝土工程、砌筑工程以及土木工程不同，与人工安装费用相比，钢构件的材料成本是相当大的。
随着钢结构建筑的发展，钢结构住宅建筑技术也必将不断的成熟，大量的适合钢结构住宅的新材料也将不断的涌现，同时，钢结构行业建筑规范、建筑的标准也将随之逐渐完善。
相信不久的将来，钢结构住宅必然会给住宅产业和建筑行业带来一声深层次的革命，钢结构的应用前景广阔！英文翻译：Steel StructureSteel in one form or another is now probably the most widely used material in the world for building construction. For the framings it has almost entirely replaced timber, except for rather special work, and it has superseded its immediate predecessors, cast iron and wrought iron, for bridges and structural frameworks in general.Steel , the most important construction material of modern times, was introduced in the nineteenth century. Steel, basically an alloy of iron and a small amount of carbon, had been mad up to that time by a laborious process that restricted it to such special uses as sword blades. After the invention of the Bessemer process in 1856, steel was available in large quantities at low prices. The enormous advantage of steel is its tensile strength; that is, it dose not lose its strength when it is under a calculated degree of tension, a force which, as we have seen, tends to pull apart many materials. New alloys have further increased the strength of steel and eliminated some of its problems, such as fatigue.Steel has great advantages for buildings. The steel normally used for structures is known as mild steel; compared with cast iron it is resilient and, up to a point known as the “elastic limit” it will recover its initial shape when the load on it is removed. Even if its loading is increased by considerable margin beyond the elastic limit, it will bend and will stay bent without breaking; whereas cast iron, though strong, is notoriously brittle and, if overloaded, will break suddenly without warning. Steel is also equally strong in both tension (stretching) and compression, which gives it an advantage over the earlier structural metals and over other building materials such as brickwork, masonry, concrete, or timber, which are strong in compression but weak in tension. It is for this reason that steel rods are used in reinforcedconcrete—the concrete resisting all compressive stresses while the steel rods take up all the tensile (stretching) forces.In steel-framed building, the horizontal girders which carry the floors and walls are themselves supported on vertical steel posts,Known as “stanchions” , which transfer the whole load of a building down to the foundations, except for the lowest floor which rests on the ground itself. A flat roof is framed in the same way as a floor. A sloping roof is carried on open steel lattice frames called roof trusses or on steel sloping rafters.The steel framework of a building is designed from the roof downwards, all the loading, both “dead” and “live” (including wind forces) , being calculated at successive levels until the total weight carried by each stanchion is determined and the foundations designed accordingly. Whih this information the structural designer calculated the sizes and shapes of the steel parts needed in the whole structure, as wall as details of all the connexions. For roof trusses and lattice girders, he uses the method of “triangulation” because a triangle is the only open frame which is inherently rigid. Therefore, lattice frameworks are nearly always built up from a series of triangles.Steel structures may be divided into three general categories: (a) framed structures, where elements may consist of tension member, columns, beams, and members under combined bending and axial load; (b) shell-type structures, where axial stresses predominate; and (c) suspension-type structures, where axial tension predominates the principal support system.Framed Structures Most typical building construction is in this category. The multistory building usually consists of beams and columns, either rigidly connected or having simple end connections along with diagonal bracing to provide stability. Even though a multistory building is three-dimensional, it usually is designed to be much stiffer in one direction than the other; thus it may reasonably be treated as a series of plane frames. However, if the framing is such that behavior of the members in one plane substantially influences the behavior in another plane, the frame must be treated as a three-dimensionalspace frame.Shell-Type Structures In this type of structure the shell serves a use function in addition to participation in carrying loads. On many shell-type structure, a framed structure may be used in conjunction with the shell. On walls and flat roofs the “skin” elements may be in compression while they act together with a framework.Suspension-Type Structure In the suspension-type structure tension cables are major supporting elements. A roof may be cable-supported. Probably the most common structure of this type is the suspension bridge. Usually a suspension bridge. Since the tension element is the most efficient way of carrying load, structures utilizing this concept are increasingly being used.Many unusual structure utilizing various combinations of framed, shell-type, and suspension-type structure have been built.Structural steel design of buildings in the USA is principally is principally based on the specifications of the American Institute of Steel Construction (AISC), The AISC Specifications are the result of the combined judgment of researchers and practicing engineers. The research efforts have been synthesized into practical design procedures to provide a safe, economical structure. The advent of the digital computer in design practice has made feasible more elaborate design rules.A lot of unusual structure, is made up of frame, shell and different combination forms of hanging structure.In the United States, the design of steel structure is mainly on the basis of regulations promulgated by the American association of steel structure. These specifications are a lot of scholars and a line engineer experience. The results of this study was comprehensive processing into a set of safe and economic design idea of design program. The design process of the digital computer prompted a more sophisticated feasible design rules.Specification includes a series of security rules, in spite of this, the designer must understand the applicability of the rules, otherwise, is likely to lead to absurd, veryuneconomical, sometimes even unsafe design result.Building rules sometimes equated with specification. These regulations cover all aspects relating to the safety, such as structure design, architectural details, fire protection, heating and air-conditioning, piping system, health systems, and lighting systems.Structure and structural components must have sufficient strength, stiffness, toughness, in order to give full play to its functions in the use of the structure. Reserves of design must provide sufficient strength to bear the load during use, that is to say, the buildings do not need to bear the possible overload. Change a structure of the original purpose, or because of excessive simplified method was adopted in the structural analysis and underestimated the load, as well as the construction process of change will cause the overload of the structure. Even within the scope of the permit, building size of the deviation can also lead to a component is lower than the strength he calculates.No matter what design principle, structure design must provide adequate security. The lack of necessary to prevent overload and intensity. Over the past 30 years, the research of how to ensure the safety design has continued. Use a variety of different probability method to study the components, fittings or system failure probability.In addition, due to structural steel components are very high cost, compared with the cost of installation of artificial, material procurement cost is huge. With other involved in the general contract of building project and civil engineering, concrete engineering, compared with the manual installation cost, material cost of steel components are considerable.With the development of steel structure, steel structure residential construction technology will also continue to mature, a lot of new materials will also be suitable for steel structure housing constantly emerging, at the same time, construction specifications, construction steel structure industry standards will be gradually perfected. Believe in the near future, the steel structure housing will inevitably brings to the housing industry and construction industry a profound revolution, the application prospect of steel structure.。