力学专业英语部分翻译(孟庆元)
力学专业英语08
力学专业英语08Lesson 8The planar motion of a rigid bodyThe planar motion of a rigid body occurs when the path of each point lies wholly in a plane, with the planar paths for all points in the body being parallel to each other. A simple example is a wheel mounted on a rotating shaft. The plane of the motion of any point in that system is perpendicular to the axis of the shaft. The restriction to planar motion substantially simplifies the kinematical description in comparison to a general three-dimensional motion. One of the attributes of this simplification is that it will be possible to depict the motion by means of a planar diagram. Without loss of generality, we will always let the xy plane coincide with the plane of motion.By definition, a rigid body is a system of particles that are always at a fixed distance from each other. This geometric restriction means that the movement of any point in the body relative to any other is limited. The existence of such kinematical relations is contrasted by the situation where particles in a system are not rigidly connected. All materials deform when forces are applied to them. The concept of a rigid body is merely a model that we create as an approximation. When we use the rigid body model, we are assuming that the movement of points due to deformation is negligible.Let us consider three arbitrarily selected points A, B and C to becsribed onto a body. The triangle ABC depicted in Figure 1 is useful for characterizing the kinematics of a rigid body motion. To describe where the triangle ABC is situated in space, it wouldbe sufficient to know the coordinates locating point A, and the angle φbetween the x axis and side AB. From this information, the position of a rigid body at any instant is defined by the absolute position of a point in the body and the angular orientation of any line in the body.Our knowledge of the information required to locate the position of a rigid body permits us to describe how the position change with time. Figure 1 depicts the position of triangle ABC at an instant subsequent to the original position of the triangle indicated by the dashed lines. The distances Δx and Δy describe the movement of point A, and Δφdescribes the angle of rotation of line AB. By the definition of a rigid body we know that the angles between all sides of the triangle are constant. It follows then that each line undergoes the same rotation. Hence, angular motion is an overall property of the motion of the body. It is the same regardless of which points in the body are being discussed.Now ,suppose that the movement of point A is specified. In addition to this movement, points B and C may move relative to point A. Because the angular motion is an overall property, the radial lines from point A to points B and C undergo the same rotation. In other words, each point moves in a circular path relative to point A. Therefore, we may concludethatThe motion of a rigid body consists of a superposition of two movements. The first par consists of a movement of all points following the motion of an arbitrarily selected point in the body. The second movement is a rotation about the selected point in which all lines rotate by the same amount.This statement is known as Chasle’s theorem.Special terms are used to describe the motion of rigid bodies.One simple type of motion occurs when every line in the body retains its original orientation, that is , there is no rotation. This is called a translation. Another simple type of motion occurs when one point in the body is fixed in space. Chasle’s theorem states that the motion of the body may be considered to consists solely of a rotation about the fixed point, this is called a pure rotation, Chasle’s theorem may be reworded to state that the motion of a rigid body is the superposition of a translation of an arbitrary point and a pure rotation about that point.Suppose that the motion of point A in the rigid body shown in Figure 2 is known, as is the angular rotation of the body, ω. Point B is an arbitrarily chosen point whose motion we seek. As shown in Fugure 2 the vectors and denote the positions of points A and B respectively. Note that ωis independent of the choice for points A and B, because Chasle’s theorem states that the rotation is the same for all lines in arigid body. The absolute value of ωis called the angular speed of the rigid body.The qualitative insight provided by Chasle’s theorem will enable us to form algebraic relations for determining the velocities and accelerations of points on a rigid body. The relationship between the absolute motions of points A and B is readily formed by referring to the position vectors depicted in figure 2, i.e. In the above equations (2) and (3) ,the velocity and acceleration of point A are denoted by V A and a A respectively. The symbols V B and a B are similarly defined for point B. The vector ωis the angular velocity of the body, and a is the angular acceleration. Both vectors are perpendicular to the plane of motion, so they are parallel to the axis for the rotational portion of the motion. As usual, the angular unit forωand a must beradians.。
工程力学专业英语翻译
When a material exhibits a linear relationship between stress and strain, it is said to be linear elastic. This is an extremely important property of many solid materials, including most metals, plastics, wood, concrete, and ceramics. The linear relationship between stress and strain for a bar in tension can be expressed by the simple equation ζ=Eε (3) in which E is a constant of proportionality known as the modulus of elasticity for the material. 当一种材料的应力与应变表现出线性关系时,我们称这种材 料为线弹性材料。这是许多固体材料的一个极其重要的性质,这 些材料包括大多数金属,塑料,木材,混凝土和陶瓷。对于被拉 伸的梁来说,这种应力与应变之间的线性关系可以用简单方程(3) ζ= Eε 来表示,这里E是一个已知的比例常数,即该材料的弹性模 量。
方程(1) 用于求解在梁中均匀分布的应力问题。它表示了应力 的单位是力除以面积。正如我们在图1中所看到的,当梁被力P拉 伸的时候,生成的应力是拉应力;如果力的方向被颠倒,导致梁 被压缩时,产生的应力被称为压应力。
A necessary condition for Eq.(1) to be valid is that the stress ζ must be uniform over the cross section of the bar. This condition will be realized if the axial force P acts through the centroid of the cross section. When the load P does not act at the centroid, bending of the bar will result, and a more complicated analysis is necessary. At present, however, it is assumed that all axial forces are applied at the centroid of the cross section unless specifically stated to the contrary. Also, unless stated otherwise, it is generally assumed that the weight of the object itself is neglected, as was done when discussing the bar in Fig.1.
计算力学第一章
element types later), and these are denoted as f1 and f 2 and are also shown in the positive sense. Assuming that both the nodal displacements are zero when the spring is undeformed, the net spring deformation is given by
Chapter
1
Spring and Bar Elements
1.1 INTRODUCTION
The finite element method (FEM) is a computational technique used to obtain approximate solutions of boundary value problems in engineering. Simply stated, a boundary value problem is a mathematical problem in which one or more dependent variables must satisfy a differential equation everywhere within a known domain of independent variables and satisfy specific conditions on the boundary of the domain. Finite element method is such a powerful technique for obtaining approximate solutions with good accuracy. The primary characteristics of a finite element are embodied in the element stiffness matrix. For a structural finite element, the stiffness matrix contains the geometric and material behavior information that indicates the resistance of the element to deformation when subjected to loading. Such deformation may include axial, bending, shear, and torsional effects. For finite elements used in nonstructural analyses, such as fluid flow and heat transfer, the term stiffness matrix is also used, since the matrix represents the resistance of the element to change when subjected to external influences. This chapter develops the finite element characteristics of two relatively simple, one-dimensional structural elements, a linearly elastic spring and an elastic tension-compression member (hereafter referred to as a bar element and also known in the finite element literature as a spar, link, or truss element). These are selected as introductory elements because the behavior of each is relatively well-known from the commonly studied engineering subjects of statics and strength of materials. Finite element analysis is based, dependent on the type of problem, on several mathematic/physical principles. First, and foremost, for spring and bar systems, we utilize the principle of static equilibrium but - and this is essential – we include deformation in the development. That is, we are not dealing with rigid body mechanics. For extension of the finite element method to more complicated elastic structural systems, we also state and apply the first theorem of Castigliano and the more widely used principle of minimum potential energy. Both theorems relate displacements and applied forces to the equilibrium conditions of a mechanical system in terms of mechanical energy. We develop the fundamentals for understanding of finite element analysis, to enable the reader to use the
力学专业英语资料(一)考研必备
I. Theoretical Mechanics理论力学Gravitational Force, Gravity重力Concurrent Force汇交力, Coplanar Force共面力Force, Torque / Moment扭矩, Couple 约束力,反应,被动力,内力Constraint Force, Reaction, Passive Force, Internal/External Force 静力学直角坐标分量,合力,平行四边形准则Rectangular Components, Resultant Force, Parallelogram Law 1. Statics Composition of Force力的合成, Free Body Diagram隔离体Vector (Magnitude, Direction)矢量, Scalar标量静力平衡平衡方程平衡条件Net Force = 0Static Equilibrium, Equation of Equilibrium, Conditions for EquilibriumNet Torque/Moment = 0Rectilinear MovementMotion of Particle粒子运动Curvilinear Movement运动学 Translation平移2. Kinematics Motion of Rigid Body刚体运动Rotation扭转Linear线性的Velocity速度, Acceleration加速度Angular有角的Momentum, Kinetic Energy, Potential Energy动量,动能,势能动力学Moment of Inertia (Rectangular, Polar), Radius of Gyration惯性矩,回转半径3. Dynamics, Kinetics Centroid (Center of Mass/Gravity)中心Vibration, Oscillation (Free/Forced/Damped/Undamped)振动Simple Harmonic Motion, Period, Frequency简谐振动,周期,频率Pendulum, Centrifugal/Centripetal Force钟摆,离/向心力II. Mechanics of Materials材料力学材料强度 Compressive, Compression压缩1. Strength of Materials Tensile, Tension (Elongation, Extension)伸长Shear, Shearing剪切Linear, Hooke’s LawElastic弹性, Elasticity Non-linearViscoelasticity, Pseudo-elasticity, Super-elasticity粘弹性,拟弹性,超弹性应力应变关系塑性 Perfect Plasticity理想塑性2. Stress-Strain Relation/Behavior Plastic, Plasticity Viscoplasticity, Viscosity黏性, Creeping徐变, RelaxationBrittle脆性, Ductile柔性Work Hardening/Softening, Strain Hardening/Softening弹性模量,弹性系数 Young’s Modulus = Axial Stress / Axial Strain杨氏模量3. Modulus of Elasticity, Elastic Modulus Shear Modulus = Shear Stress / Shear Strain剪切模量Bulk Modulus = Volumetric Stress / Volumetric Strain体积弹性模量破坏理论,失效准则,屈服准则 Maximum Principal Stress Theory最大应力准则4. Failure Theory, Failure Criteria, Yield Criteria Shear Stress TheoryMohr-Coulomb Theory库伦理论Shear Force剪力, Bending Moment弯矩, Flexural Load弯曲荷载梁 Bending Stress弯曲应力, Normal Stress正应力, Shear Stress剪应力 (Horizontal/Longitudinal, Vertical/Transverse)5. Beam Neutral Axis中性轴, Flexure屈曲, Deflection挠曲Cantilever Beam悬臂梁, Simply Supported Beam简支梁, Pin-end, Fixed End固定端Uniformly/Linearly Distributed Load均布荷载, Concentrated Load集中荷载Buckling屈曲系数, Euler’s Equation欧拉方程6. Column 长细比,有效长度,临界荷载,偏心率Slenderness Ratio, Effective Length, Critical Load/Stress, Eccentricity RatioTension弹力, Compression压缩, Uniaxial/Axial Load单轴荷载7. Shaft杆, Rod长杆, Bar Inner/Outer Diameter内/外径Torsion扭转, Torque扭矩, TwistingRadial Distance辐射距离平面应变平面应力双向应力(单轴,三轴)应变能最大/小主应力8. Plane Strain, Plane Stress, Biaxial Stress (Uniaxial, Triaxial), Strain Energy, Major (Minor) Principal Stress Deformation变形, Displacement位移, Deflection偏向Stiffness, Rigidity刚度, Hardness硬度, Flexibility弹性, ComplianceDynamic Loading动力荷载, Cyclic/Fluctuating Loading脉冲荷载, Fatigue疲劳度Thermal Stress热应力/Strain/Deformation, Coefficient of Thermal Expansion热膨胀系数Factor of Safety安全系数, Safety FactorLimit State Design极限状态设计 (Ultimate Limit State极限状态, Serviceability Limit State正常使用极限状态), Probabilistic Design概率设计III. Structural Mechanics, Structural AnalysisRod, Shaft, Bar构件Beam, Girder1. Structural Element Column, PillarPlate, Shell, MembraneShear Wall, Shear Panel2. Truss构架, 3-hinge Arch, Rigid Frame刚性框架 (Joint节点, Pin-Joint, Hinge, Node)3. Statically Determinate静定, Statically Indeterminate超静定, Degree of Static Indeterminacy, N-fold Statically Indeterminate, Degree of Freedom自由度虚功原理 Virtual Displacement, (Matrix) Displacement Method, Stiffness Method4. Virtual Work Principle Virtual Force, (Matrix) Force Method, Flexibility MethodFinite Element MethodIV. Theory of Elasticity(Differential) Equilibrium Equation, Physical Equation, Compatibility/Geometrical EquationBoundary Conditions。
力学专业英语_6
(1)
(2)
p ) is a hardening parameter. At this stage, we know nothing about where κ = κ ij (ε kl p its properties and structure. It can, for instance, be a scalar κ or a tensor κ ij (ε kl ).
Multi-axial case
Extending the above to the multi-axial case, we study a similar load cycle in a multi-axial case (Fig. 3).
Fig.3 Elasto-plastic load cycle, multi-axial case. For this, the analogue of Eq. (4) will be
p (see Fig. 4). This means that must lie behind the border line perpendicular to dε ij
this border line must be tangent to the yield surface. A further consequence is that the yield surface cannot be concave, and since it must be a closed surface enclosing σ ij * , the only possibility left is that it is convex (which in an extreme case can mean that it contains planar surface sections, as, e.g., Tresca’s yield surface). Conclusion (a) above leads directly to the flow rule
理论力学专业词汇中英对照
*静力学statics*运动学kinematics*动力学dynamics*理论力学theoretical mechanics*约束constraint*力系force system*平衡力系balanced force system*刚体rigid body*力偶force couple*力的平移定理theorem of translation of a force*主矢principal vector*主矩principal moment*物体系统(物系)body system (bs)*滑动摩擦sliding friction*摩擦角angle of friction*自锁self-locking*物体的重心the center of gravity of object *轨迹trajectory*速度velocity*加速度acceleration of a particle*运动方程equation of motion*转角angle of rotation*转动方程equation of rotation *角速度angular velocity*角加速度angular acceleration*匀速转动uniform rotation*绝对速度absolute velocity*绝对加速度absolute acceleration*相对速度relative velocity*相对加速度relative acceleration*牵连速度convected velocity*牵连加速度convected acceleration*绝对运动absolute motion*相对运动relative motion*牵连运动convected motion*科氏加速度coriolis acceleration*平面运动方程equations of plane motion *质点particle*动量momentum*冲量impulse*动量矩moment of momentum*功率power*动能kinetic energy*动静法dynamic-static method*虚位移virtual displacements*虚功virtual work。
工程力学常见专业英语词汇总结
空间变量spatial variations
直径diameter
半径radius
必要条件prerequisite
充分条件sufficient condition
质量守恒conservation of mass
动量守恒conservation of momentum
静定问题statically determinate problems
超静定问题statically indeterminate problem
轴向荷载axial load
均布荷载uniform distribution load
集中荷载concentrated load
冲击荷载shock loading
机械能守恒conservation of mechanical energy
能量守恒conservation of energy
守恒定律law of conservation
摩擦friction
内摩擦角friction angle
水平面horizontal plane
假想平面imaginary plane
相互垂直平面mutually perpendicular planes
平面外法向outward normal to the plane
前言preface
后记postscript
附录appendix
连续介质continuousmedium
非连续介质discontinuous medium
周围介质surroundingmedium
气体静力学aerostatics
气体动力学aerodynamics
变形量the amount of deformation
孟庆元工程力学专业英语阅读7
2、 what 作为关系代词,可译为“所…的东西”,“所…的”, 还可根据上下文译成“…的+名词”,“那种+名词”等
What is worrying the world greatly now is a possible shortage of coal, oil, natural gas, or other sources of fuel in the not too distant future.
An element is a simple substance that cannot be broken up into anything simpler.
元素是一种单质,它不能再分任何更简单的物质。
4、that 作为连词引出同位语从句的译法
4.1、同位语从句与主句分译,that译成“即” Energy takes many forms, but all these forms can be reduced
that 作为关系代词,引出定语从句;定语从句可以合译 也可分译,that 的处理方法也随之而异。 3.1、合译时 that 不译,在定语从句之末添“的”字
Power is the rate that mechanical move is performed at. 功率是作机械运动的速率。
3.2、分译时, that 有两种译法: a )重复所代替的名词;b)译成“它” Master is composed of molecules that are composed of atoms. 物质由分子组成,而分子由原子组成。
to the statement that energy is the capacity to do work. 能量具有很多形式,但所有这些形式都可以归纳为这
孟庆元工程力学专业英语阅读3
最好的导体电阻最小,最差的导体电阻最大。
2、某些句子结构须增加关联词
If A is equal to D, A plus B equals D plus B. 若A = D,则A + B = D + B
G Gr
(2)
Equations (1) and (2) relate the strain and stress at the surface of the shaft to the
angle of twist per unit length.
当一个杆件处于纯扭转状态是,其扭转角沿杆件 纵向方向的变化率(即单位长度的扭转角)d / dx是
sections of the bar remain straight and undistorted during twisting, we see that an
interior element situated on the surface of an interior cylinder of radius is also in
6、补充概括性的词 The frequency, wavelength, and speed of sound are closely related. 频率、波长和声速之间是密切相关的。
The resistance of the pipe to the flow of water through it depends upon the length of the pipe, the diameter of the pipe, and the feature of the inside walls (rough or smooth).
力学专业英语25
材料的基本变形当以物体承受荷载,荷载或者来自于作用于外表面的力,或者是重力的影响,或者是类似的施加于整个物体的力,物体产生应力和变形。
对施加于连续体上力的研究形成了连续介质力学。
对连续介质力学问题的公式化表述中,非常重要的一部分是描述作用于单元体上应力和单元体上产生的变形的关系。
在这里,变形意味着物体几何形状的改变。
依赖于工程材料的自然属性和作用力的大小,材料可以以多种不同的方式变形。
它可以以弹性、塑性、粘弹性或者粘性方式变形。
这些变形的每一种形式可以简单定义和描述如下:弹性变形弹性变形可以定义为可逆的变形,也就是,当作用力移除以后,物体可以恢复到它原来的形状,并且所有储存的能量也可以恢复。
任何时候,施加荷载后,不论应力是切应力、正应力或者静水应力,它都会产生相应的弹性变形。
所有,如果给出了作用载荷的大小,那么对应的变形量就可以唯一确定。
其所包含的物理过程是,通过改变原子间的距离,原子键的简单延伸。
几乎所有的晶体材料在相当低的应力下表现为弹性。
部分的没有特定取向晶体聚合物,在低温下基本上也是弹性的。
表征各向同性材料的弹性特性的材料属性是杨氏模量E,切变模量G,体积模量K 和泊松比v。
对于各向同性材料只有两个属性的独立的。
塑性变形塑性变形是永久变形,也就是,在荷载移除之后,物体依然变形并且完成了净功。
包含的物理过程是原子间的滑动,永久的改变了它们相互间的位置。
当作用于金属材料时,正应力并没有显著的影响滑动过程。
所以,它可以表述为只有切应力可以导致金属材料的塑性变形。
变形的维度依赖于加载历史,所以不可以唯一的由应力确定。
包含的一些重要的参数是,塑性变形的切应力和加工硬化率。
对于大多数准静力加载情况,塑性变形是独立于时间,也就是,它不依赖于加载的持续时间。
大多数在高应力下的金属显示出塑性特性。
在高温下,金属承受着依赖于时间的塑性变形叫做蠕变。
粘性变形粘性变形是永久变形,通过变形的时间率来表征,变形是和施加的载荷成比例的。
力学专业英语翻译 42 课
聚合物的粘性行为众所周知,聚合物的现象学的本构关系是非常复杂的。
除了在一些特别的环境下,很难概括出很长时间内聚合物的行为,因为载荷,温度和加载时间都会影响本构关系。
然而,很清楚的是聚合物表现为黏弹塑性行为。
在低温和高荷载下,弹性和塑性变形处于主导地位,但是在高温和高荷载下,粘性行为要更重要。
在室温时,聚合物承受一个中等的载荷,其中一个有区别的力学行为特征是粘弹性。
聚合物的粘弹性特性可以由弹簧阻尼系统来近似模仿。
非常有名的连个模型是Maxwell模型和Voigt-Kelvin模型。
如图1所示,这些模型描述了线粘弹性,概括了聚合物的真实粘弹性行为。
尽管过去尝试使用许多弹簧和阻尼的组合来建立真实固体的本构关系基本上失败了,仍然可以使用这些模型进去一定的概括。
定性的说,Maxwell模型表明在瞬时加载时,固体表现为弹性,然后发生粘性变形,这是由于弹簧是瞬时变形的和阻尼的变形率和应用的荷载成比例。
在Voigt-Kelvin固体情况下,没有瞬态变形,最大的应变也是被弹簧限制的。
尽管真实聚合物的力学行为不能够被弹簧和阻尼的组合精确模仿,真实聚合物的许多特征可以从简单的Maxwell和Voigt-kelvin模型的特征来理解。
考虑Maxwell模型的本构关系,总应变是弹性和塑性变形的的总和,也就是εij=εij e+εijν(1)εij e是弹性应变,εijν是粘性部分造成的应变。
应变εij e和εijν与应力的关系是ε11e=σ11E(2)dε11νdt =σ11η(3)对等式(1)和(2)求导,并结合等式(3)Maxwell固体的本构关系可以写为dε11 dt =1Edσ11dt+σ11η(4)Voigt-Kelvin模型的本构关系也可以类似得到。
从等式(4)可以看出在拉力测试中获得的通常的应力—应变关系将会非常敏感的依赖于应变率。
对于有着很大粘性或者在很高加载速率的材料,Maxwell表现的像Hookeian固体,Voigt-kelvin表现的像刚体。
力学专业外语1
electrodynamics 电动力学
thermodynamics 热力学
1 Motion in one dimension rotate v. 旋转、转动 spin n. 旋转、自旋
trajectory n. 轨道
vibrate v. 振动
molecule n. 分子
1 Motion in one dimension dimension n.尺寸、维(数)、度(数)、量纲
probe n. 探针,调查,探测针 v. 用探针测,详细调查
space probe 空间探测器 bubble n. 泡沫 chamber n. 室,房间 bubble chamber 气泡室 decay n. v. 衰退、腐败、腐蚀、衰变、风化
most important
就海洋的大部分而言,盐的作用是不重要的,而 水压的作用才是最重要的
mechanical energy.
被流过坝的水流带动旋转的水轮为势能转化成有 用的机械能提供了一个很好的例子。
Translation 2
In motions of rotation angular momentum appears in much the same way as linear
proton n. 质子
electron n. 电子
translation n. 翻译、平移 a reference frame 参考系Biblioteka Translation 1
A water wheel,turned by water flowing over a weir,furnishes a good example of potential energy being turned into useful
最新力学专业英语单词表
Aabrasion n. 磨损[耗]abrasive n. a. (研)磨料(的)磨损abscissa n. 横坐标actuation n. 驱动align v. 调整,对中,校直alloy n. 合金alternative n. a. 交替(的),可供选择的aluminum n. 铝amortize v. 阻尼,缓冲,分期偿还anisotropy n. 各项异性annealing n. 退火annealing n. 退火antiparallelogram n. 反平行四边形anvil n. (锤)砧,砧座armor n. 铠甲assumption n. 假定设想, 担任(职责等), 假装at one’s command 自由使用,支配attainable a. 可达[得]到的austenitic a. 奥氏体的Bbar n. 杆件bass n. 黄铜be distinguished from 与…区分be referred to as 叫做,称为,被认为abnormal a. 非正常的be termed… 被称为……beam n. 横梁,一束bearing n. 轴承bending n. 弯曲,折弯bias vt. n. (使)偏向[重,差]billet n. 坯料,锻坯binary a. 二[双, 复]的, 二元的bismuth n. 铋blacksmith n. 锻工blank n.坯料,(冲压)板坯block n. (模)块blow molding 吹塑(法)brake forming [压]折弯(机)成型branch n. v. 分(部,支)braze n. vt. 硬钎焊,铜焊breakage n. 断裂breakdown n. 破坏,击穿brittleness n. 脆性, 脆度broken up 破[断]裂,分散bronze n. 青铜broom n. 扫帚buckling n. 弯[翘]曲,挠曲buttwelding 对头(缝)焊Ccadmium n. 镉capability n. 能力,性能,容量carbide n. 碳化物,硬质合金carbon n. 碳carbon tetrachloride 四氯化碳casting n. 铸造[件]category n. 种类category n. 种类、类别cavity n. 模膛,型槽centripetal a. 向心的centroid n. 质心;形心closed impression die 闭式锻模coefficient n. 系数coherent a. 互相凝聚的,协调一致coincide with 一致,相符cold[hot] working 冷[热]加工collinear adj. 共线的comparative adj. 比较的,相当的compression molding 压塑,模压(法)compression n. 压缩compressive stress 压(缩)应力configuration n. 外形,配置,排布confine vt. 限制,约束constituent n. a.组成[的,部分] constrain(t) v. n. 强制,约束constrained a. 约束的,限定的consumer goods 消费品continuum n. 连续(体)contour n. 外形、轮廓线convert v. 转变[化]convert v. 转变[换],更换copper n. 铜copper-base alloy 铜基合金corrosion n. 腐蚀coupler n. 连接件,连杆cracking n. 裂纹craftsman n. 技工criterion (pl. criteria) n. 标准, 判据, 准则critical strain 临界应变critical temperature 临界温度crystalline n. a. 结晶[的],晶体cuploa n. 冲天炉Ddecoration n. 装饰deep drawing 深冲(压)definite a. 确定的deflection n. 偏移[转,离],挠曲deformation n. 变形density n. 密度derivative of M with respect to NM对于N的导数design specifications:设计技术要求destructive a. 破坏(性)的,有害的deterioration n. 变坏,退化,损耗determinant n. 行列式die failure 模具损坏die life 模具寿命die n. 模具,锻[冲]模,凹模die-casting n. 模铸[件]discount v. 打折扣,忽视discrete a. 不连续的,单个的disjoin v. 拆散,分开dislocation n. 位错displacement n. 位移,排量,替换distributed forces n. 分力diversity n. 不同,多样性draft n. 模锻斜度drawing n. (锻坯)拔长,[线,管材]拉拔drawn out 拔长drop forging 落锻,锤模锻ductility n. 延展性,可锻性dump v. 倾倒,堆放Eeccentricity n. 偏心[度,率]efficiency n. 效率elastic a. 弹性的elasticity n. 弹性electric resistance-type strain gage n. 电阻应变片electrode n. 电(焊)极, 焊条elimination n. 消除,淘汰elongation n. 伸长(量)embed v. 嵌入、加在层间envision v. 想象equilibrium n. 平衡erosion n. 腐[侵,烧]蚀extract vt. 提炼,萃取extrusion n. 挤压Ffabricate vt. 制造[备],生产factor n. 因素failure n. 失效;破坏fasten(ing) v. n. 连接(件), 紧固(件)ferrous a. (含)铁的ferrous metals 黑色金属filler n. 填充(剂)fine adj. 细的finite element 有限元fiux-shielded arc welding 熔剂保护电弧焊flexibility n. 柔(韧)性,灵活性final flow line 流线flow stress 流动应力flux n. 焊接,助熔剂flux n. 通量,流量forging 终锻forging n. 锻造,锻件foundry n. 铸造[车间]four-bar linkage 四杆机构frame n. 机架,构架friction n. 摩擦furnace n. [熔,高]炉fusion n. 熔化,熔接fusionwelding 熔焊,熔接Ggauge vt. 测[计]量,校验gear ration 齿轮[速、齿数] 比geometry n. 几何形状globular a. 球形(状)的gradient n. 坡[梯]度,斜率grain n. 晶粒grain size 晶粒度graphite n. 石墨grips pl.c.n. 夹具gross n. 总共,重大Hhanding n. 处理,装卸,搬运handle n. 手柄hardening n. 淬火hardness n. 硬度hazard n. 危险,未知数,意外事故heat checking 热裂纹,龟裂heat treatment 热处理higher acceleration 高阶加速度homogeneous a. 均匀的hydraulic adj. 液压的hydraulic press 液压机hydrochloric acid 盐酸Iideal mechanical advantage理想的机械效率immortalize vt. (使)不朽(灭)impact n. v. 冲击,碰撞impart v. 给与,分给impression die forging 模锻impression n. 模膛,型腔(槽)impurity n. 杂质,不纯in connection with 关于,与…相关incline v. (使)倾斜increment n. 增量inertia n. 惯性(物),惯量ingot n. (钢)锭inherent a. 固有的,先天的,本质的initiation n. 开[初]始,发[产]生injection molding 注射模塑(法)inorganic acid 无机酸insulate v. (使)隔离, 绝缘integrity n. 完整性,完全[善]inversion n. 转换,变换investigate v. 调查,研究iron n. 铁It follows that …由此可见,由此得出结论..., 因而断定...it is certain to 必然,一定it is likely that 很可能iterative a. 反复的,迭代的Jjerk n. 震动jet engine 喷气发动机joint n. 结合, 铰链n. 连接的Kkinematic a. 运动学的,运动学上的kinematic chain 运动链knead v. 揉搓[制]Llead n. 铅linear analog 线性模拟link n. 构件,杆件v. 连接longitudinal adj. 经度的; 纵向的;loop n. 环,回路,循环low-carbon steal 低碳钢lubrication n. 润滑luster n. 光泽Mmachine-building 机械制造machine-tool shipments: 机床装运费machining operations: 机床操作,加工工艺magnesium n. 镁manageable a. 可控制的manual a. 手动的,人工的manual skill 手工技艺matrix n. 矩阵mechanical fatigue 机械疲劳mechanical press 机械压力机mechanics n. 力学mesh n. v. 网格,啮合metallic a. (含)金属(制)的metallurgical a. 冶金(学)的metalworking n. 金属压力加工microscopic a. 显微的,微观的microshrinkage n. 显微缩孔microstructure n. 显微组织military n. a. 军队[事,人]的mill n. 轧钢机,铣床mineral a. 矿物的mode n. 方式,状态,模式model n. 模型,样品modify v. 修改,调解,变更mould (mold) n. 模子,铸模,塑模movability n. 可动的,易动的multidisciplinary n. 多学科的multiloop n. 多环链, a 多回路的multiplier n. 放大器,乘法器Nneglect vt. 忽略nickel n. 镍nonferrous metals 有色金属normal adj. 法向的normalizing n. 正火,(正)常化Oopen die forging 自由锻optimization n. 优化,优选(法)ordinate n. 纵坐标orientation n. (定)方向,方位oriented 导向oscillate v. 摆动,摇动overhead : 管理费overheat n. 过热overlap v. 搭接,重叠overload n. v. (使)过[超]载oxidation n. 氧化oxy-acetylene n. a.氧(乙)炔(的)Ppackaging machinery 包装机械parallelogram n. 平行四边形parameter n. 参数parameter n. 参数paraphrase v. 解释,意译penetration n. 贯穿,渗透permanent a. 永久的perpendicular adj. 垂直的pig iron 生铁pin n. 销[钉],铰销pitch v. 投掷pivot n. 枢(轴), 轴销, 回转副plastic working 塑性加工plasticity n. 塑性polygon n. 多变形porosity n. 多孔性,疏松pose v. 提出,摆出…姿态pour v. 浇注powder metallurgy 粉末冶金precision forming 精密成型preconceive v. 预想、事先想好preprocess vt. 预(先)加工,预处理prescribe v. 规定,指示pressurewelding 压力焊prime mover 原动件,驱动件prismatic adj. 棱柱的pristmatic a. 棱柱(形)的prolonged a. 长时间的, 持续很久的pyrometer n. 高温计Qquenching n. 淬火,骤冷Rram n. 锤头,滑块,活动横梁ramp n. 斜板,斜坡rapid-impact blow 快速冲击,猛打recrystallization n. 再结晶recycle v. 反复[循环]利用refine v. 精炼[制],细化refinement n. 精炼[制],细化regarding 考虑到,关于removal n. 除去,放出response n. 反[响]应,灵敏度restriction n. 限制retard vt. n. (使)延缓,推迟retarding media 延缓介质reversal n. 颠倒,相反revolute v. 旋转, 转动, n. 回转体rigid a. n. 坚硬的,刚性,刚度rivet n. v. 铆钉,铆接rock n. 摆动,v. 摇动rocker n. 摇杆roll n. v. 轧辊,滚,轧roll v. 滚动rule of thumb 据经验和实际所得的做法rupture n. 破[开]裂Sscoop n. 勺子,铲斗,v.挖,掘,铲second acceleration 二节加速度sensitive a. 灵敏的,敏感的shear stress 剪应力shielding n. 遮护,屏蔽simultaneously ad. 同时sinter n. vt. 烧结sizing n. 整形,校正,定径skeleton diagram 草图, 示意图slider-crank mechanism 四杆机构slope v. (使)倾斜soaking(=holding) n. 均热,保温solder(ing) v. n. 软钎焊,(低温)焊料solidfy v. (使)凝固solvent n. 溶剂solvent n. a. 溶剂(的)somewhat adv. 稍微soundness n. 致密性,坚固性,无缺陷specific gravity 比重specification n. 操作规程,技术指标,说明书spheroidizing n. 球化(处理)spotwelding 点焊spring-back n. 回弹squeeze v. 挤压stainless steel 不锈钢stamp n. 冲压standard gage n. 标距standardize v. 标准化steep n. a. 陡(坡)的,急剧的stock n. 坯料,原材料strain (rate) n. 应变strain n. 应变strain[deformation] hardening 应变[变形]硬化strength n. 强度stress field 应力场stress n. 应力stress n. 应力stress relieving 消除应力处理stretch forming 张拉成型strike v. 攻[打]击,放电stroke n. 行程,冲程subsequently ad. 随后suitability n. 适应性sulphuric acid 硫酸surface finish 表面光洁度sweep v. 扫荡[描],掠过symmetrical a. 轴对称的Ttempering n. 回火tensile stress 拉(伸)应力tension n. 拉伸test specimens n. 试样thermal fatigue 热疲劳thermal refining 调质处理tin n. 锡tolerance n. 公差topologically adv. 拓扑学地torch n. 焊炬torque n. 力矩,扭矩toughness n. 韧性trajectory n. 轨迹transition n. 过渡区transmission angle 传动角trial-and-error 试凑法turbine n. 涡[汽]轮机,透平机U-Zultimate a. n. 最终的,首要的,极限upset n. 镦粗,顶锻vacuum forming 真空模塑validity n. 正确有效,合法variable n. 变量warm working 温加工,温锻wear v. 磨损weld(ing) v. n. 焊接,熔焊with ease 轻易,很容易的yield stress 屈服应力zinc n. 锌。
课-程:-(填中、英文名称)
课程简介课程:建筑制图[Architectural Drawing]编号:学时:32学分:2内容提要:本课程的主要内容有制图基本知识,投影基本知识,点、直线、平面的投影,轴测投影,组合体视图,工程图样的表达方法,建筑形体的透视,正投影图中的的阴影和透视阴影等。
使用教材:《建筑制图》胡志华编苏州大学出版社2002年适用专业:城市规划、建筑学、艺术设计[室内]、园林先修课程:无课程:工程制图基础B[Basic of Engineering Drawing]编号:学时:32学分:2内容提要:本课程的主要内容有制图基本知识和基本技能,投影的基本知识,空间几何元素的投影及其相对位置,立体的投影及其表面的交线,轴测投影图,组合体视图,机件表达方法,标准件及常用件的画法,零件图及装配图的基本读图与绘图方法。
使用教材:《机械制图》周蔼明编同济大学出版社2003年第三版适用专业:电子信息工程、电子信息科学与技术先修课程:无课程:画法几何及土建制图(一)[Descriptive Geometry And Civil Engineering Drawing(1)]编号:学时:48学分:3内容提要:本课程的主要内容有投影的基本知识,空间几何元素的投影,立体的投影及其表面的交线,轴测投影图的画法,组合体视图,建筑形体表达方法。
使用教材:《画法几何及土木工程制图》王书文编苏州大学出版社2008年第一版适用专业:土木工程先修课程:无课程:画法几何及土建制图(二) [Descriptive Geometry And Civil Engineering Drawing(2)]编号:学时:32学分:2内容提要:制图基本知识与技能,组合体绘图,房屋建筑施工图、结构施工图、给水排水施工图的读图与绘图。
使用教材:《画法几何及土木工程制图》王书文编苏州大学出版社2008年第一版适用专业:土木工程先修课程:画法几何及土建制图(一)课程:土建制图基础[Basic of Civil Engineering Drawing]编号:学时:48学分:3内容提要:本课程的主要内容有投影的基本知识,空间几何元素的投影,立体的投影及其表面的交线,轴测投影图的画法,制图基本知识与技能,组合体视图,建筑形体表达方法,房屋建筑施工图、结构施工图的读图与绘图。
力学专业英语词汇翻译
力学专业英语词汇翻译牛顿力学Newtonian mechanics经典力学classical mechanics工程力学engineering mechanics固体力学solid mechanics一般力学general mechanics应用力学applied mechanics流体力学fluid mechanics理论力学theoretical mechanics静力学statics运动学kinematics动力学dynamics材料力学materials mechanics结构力学structural mechanics实验力学experimental mechanics计算力学computational mechanics力force作用点point of action作用线line of action力系system of forces力系的简化reduction of force system等效力系equivalent force system刚体rigid body力的可传性transmissibility of force平行四边形定则parallelogram rule力三角形force triangle力多边形force polygon零力系null-force system平衡equilibrium力的平衡equilibrium of forces平衡条件equilibrium condition平衡位置equilibrium position平衡态equilibrium state分析力学analytical mechanics拉格朗日乘子Lagrange multiplier拉格朗日[量] Lagrangian循环积分cyclic integral哈密顿[量] Hamiltonian哈密顿函数Hamiltonian function正则方程canonical equation正则摄动canonical perturbation正则变换canonical transformation正则变量canonical variable哈密顿原理Hamilton principle作用量积分action integral哈密顿--雅可比方程Hamilton-Jacobi equation作用--角度变量action-angle variables泊松括号poisson bracket边界积分法boundary integral method运动稳定性stability of motion轨道稳定性orbital stability渐近稳定性asymptotic stability结构稳定性structural stability倾覆力矩capsizing moment拉力tensile force正应力normal stress切应力shear stress静水压力hydrostatic pressure集中力concentrated force分布力distributed force线性应力应变关系linear relationship between stress and strain 弹性模量modulus of elasticity横向力lateral force transverse force轴向力axial force拉应力tensile stress压应力compressive stress平衡方程equilibrium equation静力学方程equations of static比例极限proportional limit应力应变曲线stress-strain curve拉伸实验tensile test‘屈服应力yield stress极限应力ultimate stress轴shaft梁beam纯剪切pure shear横截面积cross-sectional area挠度曲线deflection curve曲率半径radius of curvature曲率半径的倒数reciprocal of radius of curvature纵轴longitudinal axis悬臂梁cantilever beam简支梁simply supported beam微分方程differential equation惯性矩moment of inertia静矩static moment扭矩torque moment弯矩bending moment弯矩对x的导数derivative of bending moment with respect to x弯矩对x的二阶导数the second derivative of bending moment with respect to x 静定梁statically determinate beam静不定梁statically indeterminate beam相容方程compatibility equation补充方程complementary equation中性轴neutral axis圆截面circular cross section两端作用扭矩twisted by couples at two ends刚体rigid body扭转角twist angle静力等效statically equivalent相互垂直平面mutually perpendicular planes通过截面形心through the centroid of the cross section一端铰支pin support at one end一端固定fixed at one end弯矩图bending moment diagram剪力图shear force diagram剪力突变abrupt change in shear force、旋转和平移rotation and translation虎克定律hook’s law边界条件boundary condition初始位置initial position、力矩面积法moment-area method绕纵轴转动rotate about a longitudinal axis横坐标abscissa扭转刚度torsional rigidity拉伸刚度tensile rigidity剪应力的合力resultant of shear stress正应力的大小magnitude of normal stress脆性破坏brittle fail对称平面symmetry plane刚体的平衡equilibrium of rigid body约束力constraint force重力gravitational force实际作用力actual force三维力系three-dimentional force system合力矩resultant moment标量方程scalar equation、矢量方程vector equation张量方程tensor equation汇交力系cocurrent system of forces任意一点an arbitrary point合矢量resultant vector反作用力reaction force反作用力偶reaction couple转动约束restriction against rotation平动约束restriction against translation运动的趋势tendency of motion绕给定轴转动rotate about a specific axis沿一个方向运动move in a direction控制方程control equation共线力collinear forces平面力系planar force system一束光 a beam of light未知反力unknown reaction forces参考框架frame of reference大小和方向magnitude and direction几何约束geometric restriction刚性连接rigidly connected运动学关系kinematical relations运动的合成superposition of movement固定点fixed point平动的叠加superposition of translation刚体的角速度angular speed of a rigid body质点动力学particle dynamics运动微分方程differential equation of motion 工程实际问题practical engineering problems变化率rate of change动量守恒conservation of linear momentum 定性的描述qualitative description点线dotted line划线dashed line实线solid line矢量积vector product点积dot product极惯性矩polar moment of inertia角速度angular velocity角加速度angular accelerationinfinitesimal amount 无穷小量definite integral 定积分a certain interval of time 某一时间段kinetic energy 动能conservative force 保守力damping force 阻尼力coefficient of damping 阻尼系数free vibration 自由振动periodic disturbance 周期性扰动viscous force 粘性力forced vibration 强迫震动general solution 通解particular solution 特解transient solution 瞬态解steady state solution 稳态解second order partial differential equation 二阶偏微分方程external force 外力internal force 内力stress component 应力分量state of stress 应力状态coordinate axes 坐标系conditions of equilibrium 平衡条件body force 体力continuum mechanics 连续介质力学displacement component 位移分量additional restrictions 附加约束compatibility conditions 相容条件mathematical formulations 数学公式isotropic material 各向同性材料sufficient small 充分小state of strain 应变状态unit matrix 单位矩阵dilatation strain 膨胀应变the first strain invariant 第一应变不变量deviator stress components 应力偏量分量the first invariant of stress tensor 应力张量的第一不变量bulk modulus 体积模量constitutive relations 本构关系linear elastic material 线弹性材料mathematical derivation 数学推导a state of static equilibrium 静力平衡状态Newton‘s first law of motion 牛顿第一运动定律directly proportional to 与……成正比stress concentration factor 应力集中系数state of loading 载荷状态st venant’ principle 圣维南原理uniaxial tension 单轴拉伸cylindrical coordinates 柱坐标buckling of columns 柱的屈曲critical value 临界值stable equilibrium 稳态平衡unstable equilibrium condition 不稳定平衡条件critical load 临界载荷a slender column 细长杆fixed at the lower end 下端固定free at the upper end 上端自由critical buckling load 临界屈曲载荷potential energy 势能fixed at both ends 两端固定hinged at both ends 两端铰支tubular member 管型杆件transverse dimention 横向尺寸stability of column 柱的稳定axial force 轴向力elliptical hole 椭圆孔plane stress 平面应力nominal stress 名义应为principal stress directions 主应力方向axial compression 轴向压缩dynamic loading 动载荷dynamic problem 动力学问题inertia force 惯性力resonance vibration 谐振static states of stress 静态应力dynamic response 动力响应time of contact 接触时间length of wave 波长resonance frequency 谐振频率自由振动free vibration固有振动natural vibration暂态transient state环境振动ambient vibration反共振anti-resonance衰减attenuation库仑阻尼Coulomb damping参量[激励]振动parametric vibration模糊振动fuzzy vibration临界转速critical speed of rotation阻尼器damper半峰宽度half-peak width相平面法phase plane method相轨迹phase trajectory解谐detuning耗散函数dissipative function硬激励hard excitation硬弹簧hard spring, hardening spring谐波平衡法harmonic balance method久期项secular term自激振动self-excited vibration软弹簧soft spring ,softening spring软激励soft excitation模态分析modal analysis固有模态natural mode of vibration同步synchronization频谱frequency spectrum基频fundamental frequency缓冲器buffer风激振动aeolian vibration嗡鸣buzz倒谱cepstrum颤动chatter蛇行hunting阻抗匹配impedance matching机械导纳mechanical admittance机械效率mechanical efficiency机械阻抗mechanical impedance随机振动stochastic vibration, random vibration 隔振vibration isolation减振vibration reduction方位角azimuthal angle多体系统multibody system静平衡static balancing动平衡dynamic balancing静不平衡static unbalance动不平衡dynamic unbalance现场平衡field balancing不平衡unbalance不平衡量unbalance质量守恒conservation of mass动量守恒conservation of momentum能量守恒conservation of energy动量方程momentum equation能量方程energy equation结构分析structural analysis结构动力学structural dynamics拱Arch三铰拱three-hinged arch抛物线拱parabolic arch圆拱circular arch穹顶Dome空间结构space structure空间桁架space truss雪载[荷] snow load风载[荷] wind load土压力earth pressure地震载荷earthquake loading弹簧支座spring support支座位移support displacement支座沉降support settlement超静定次数degree of indeterminacy机动分析kinematic analysis结点法method of joints截面法method of sections结点力joint forces共轭位移conjugate displacement影响线influence line三弯矩方程three-moment equation单位虚力unit virtual force刚度系数stiffness coefficient柔度系数flexibility coefficient力矩分配moment distribution力矩分配法moment distribution method力矩再分配moment redistribution分配系数distribution factor矩阵位移法matri displacement method单元刚度矩阵element stiffness matrix单元应变矩阵element strain matrix总体坐标global coordinates高斯--若尔当消去法Gauss-Jordan elimination Method屈曲模态buckling mode线弹性断裂力学linear elastic fracture mechanics, LEFM 弹塑性断裂力学elastic-plastic fracture mechanics, EPFM 断裂Fracture脆性断裂brittle fracture解理断裂cleavage fracture蠕变断裂creep fracture裂纹Crack裂缝Flaw缺陷Defect割缝Slit微裂纹Microcrack折裂Kink椭圆裂纹elliptical crack深埋裂纹embedded crack损伤力学damage mechanics损伤Damage连续介质损伤力学continuum damage mechanics细观损伤力学microscopic damage mechanics损伤区damage zone 疲劳Fatigue低周疲劳low cycle fatigue应力疲劳stress fatigue随机疲劳random fatigue蠕变疲劳creep fatigue腐蚀疲劳corrosion fatigue疲劳损伤fatigue damage疲劳失效fatigue failure疲劳断裂fatigue fracture疲劳裂纹fatigue crack疲劳寿命fatigue life疲劳破坏fatigue rupture疲劳强度fatigue strength交变载荷alternating load交变应力alternating stress应力幅值stress amplitude应变疲劳strain fatigue应力循环stress cycle应力比stress ratio安全寿命safe life过载效应overloading effect循环硬化cyclic hardening循环软化cyclic softening环境效应environmental effect裂纹片crack gage裂纹扩展crack growth, crack Propagation裂纹萌生crack initiation循环比cycle ratio实验应力分析experimental stress Analysis工作[应变]片active[strain] gage基底材料backing material应力计stress gage零[点]飘移zero shift, zero drift应变测量strain measurement应变计strain gage应变指示器strain indicator应变花strain rosette应变灵敏度strain sensitivity机械式应变仪mechanical strain gage直角应变花rectangular rosette引伸仪Extensometer应变遥测telemetering of strain横向灵敏系数transverse gage factor横向灵敏度transverse sensitivity焊接式应变计weldable strain gage平衡电桥balanced bridge粘贴式应变计bonded strain gage粘贴箔式应变计bonded foiled gage粘贴丝式应变计bonded wire gage桥路平衡bridge balancing电容应变计capacitance strain gage补偿片compensation technique补偿技术compensation technique基准电桥reference bridge电阻应变计resistance strain gage温度自补偿应变计self-temperature compensating gage 半导体应变计semiconductor strain Gage计算结构力学computational structural mechanics加权残量法weighted residual method有限差分法finite difference method有限[单]元法finite element method配点法point collocation里茨法Ritz method广义变分原理generalized variational Principle最小二乘法least square method胡[海昌]一鹫津原理Hu-Washizu principle赫林格-赖斯纳原理Hellinger-Reissner Principle修正变分原理modified variational Principle约束变分原理constrained variational Principle混合法mixed method杂交法hybrid method边界解法boundary solution method有限条法finite strip method半解析法semi-analytical method协调元conforming element非协调元non-conforming element混合元mixed element杂交元hybrid element边界元boundary element强迫边界条件forced boundary condition 自然边界条件natural boundary condition 离散化Discretization离散系统discrete system连续问题continuous problem坐标变换transformation of Coordinates 广义位移generalized displacement广义载荷generalized load广义应变generalized strain广义应力generalized stress界面变量interface variable节点node, nodal point[单]元Element角节点corner node边节点mid-side node内节点internal node无节点变量nodeless variable杆元bar element桁架杆元truss element梁元beam element二维元two-dimensional element一维元one-dimensional element三维元three-dimensional element轴对称元axisymmetric element板元plate element壳元shell element厚板元thick plate element三角形元triangular element四边形元quadrilateral element四面体元tetrahedral element曲线元curved element二次元quadratic element线性元linear element三次元cubic element四次元quartic element等参[数]元isoparametric element单元分析element analysis单元特性element characteristics刚度矩阵stiffness matrix几何矩阵geometric matrix等效节点力equivalent nodal force节点位移nodal displacement节点载荷nodal load位移矢量displacement vector载荷矢量load vector质量矩阵mass matrix集总质量矩阵lumped mass matrix相容质量矩阵consistent mass matrix阻尼矩阵damping matrix瑞利阻尼Rayleigh damping刚度矩阵的组集assembly of stiffness Matrices 载荷矢量的组集consistent mass matrix质量矩阵的组集assembly of mass matrices单元的组集assembly of elements局部坐标系local coordinate system局部坐标local coordinate面积坐标area coordinates体积坐标volume coordinates曲线坐标curvilinear coordinates静凝聚static condensation形状函数shape function试探函数trial function检验函数test function权函数weight function样条函数spline function节点号node number单元号element number带宽band width带状矩阵banded matrix变带状矩阵profile matrix带宽最小化minimization of band width波前法frontal method子空间迭代法subspace iteration method行列式搜索法determinant search method逐步法step-by-step method增量法incremental method初应变initial strain初应力initial stress切线刚度矩阵tangent stiffness matrix割线刚度矩阵secant stiffness matrix模态叠加法mode superposition method 平衡迭代equilibrium iteration子结构Substructure子结构法substructure technique网格生成mesh generation结构分析程序structural analysis program 前处理pre-processing后处理post-processing网格细化mesh refinement应力光顺stress smoothing组合结构composite structure。
力学专业英语Translation1
G1 Basic Concepts in MechanicsWork is defined as force multiplied by the distance over which the force acts. Work is measured in metre-kilograms.(直译+意译法)功是指力与该力方向上位移的乘积,单位是米•牛顿(焦耳)。
A metre-kilogram equals the work done by a force of one kilogram acting through a distance of one metre.(直译+意译法)一焦耳的功相当于一千克物体在力的作用下(沿力的方向)移动一米。
For example, if a work task involves lifting a 300-kilogram machine two and one-half metres into a truck, then 750 metre-kilograms of work is required.(直译+意译法)譬如,将一个重达300千克的机械举起2.5米,置于卡车中,这需要750焦耳的功。
Since no humans can lift 300 kilograms directly, a device must be employed to modify the required effort into something manageable.(直译+意译法)因为没有人能直接举起300千克,所以必须动用一个设备以可行的方式实现所需的工作量。
One common device is an inclined plane - in this case, a loading ramp that slopes from the ground to the truck. If the ramp were 10 meters long and friction forces were negligibly small, then 75 kilograms of force would be required to roll the machine up the ramp.(直译+意译法)一个常见的设备是一个斜面——在该情况下,是一个从地面连接到卡车的荷载斜板。
力学专业英语Translation2
G1 Die Life and Die Failure模具的寿命及其失效Proper selection of the die material and of the die ([daɪ] n.模具)manufacturing technique determines, to a large extent, the useful life of forming dies.(直译法)模具材料的恰当选择及其制造工艺,在很大程度上决定了模具的使用寿命。
Dies may have to be replaced for a number of reasons, such as changes in dimensions due to wear or plastic deformation, deterioration([ dɪˌtɪrɪəˈreʃən ]n.变坏,退化,损耗)of the surface finish, breakdown of lubrication([ lubrɪˈkeʃən ] n.润滑), and cracking or breakage.(直译法)模具可能会因为一系列原因被替换,比如由于磨损或塑性变形导致的尺寸变化,表面平整度变差,润滑故障,和裂纹即破裂。
In hot impression die forging, the principal modes of die failure are erosion, thermal ([ ˈθɜ:rml ] adj.热的) fatigue ([ fəˈtiɡ ] n.疲劳), mechanical fatigue and permanent (plastic) deformation.(直译法)在热压印模锻造中,模具失效的主要模式是腐蚀作用、热疲劳、机械疲劳和永久(塑性)变形。
In erosion [ɪ'rəʊʒ(ə)n], also commonly called die wear, material is actually removed from the die surface by pressure and sliding of the deforming material, wear resistance of the die material, die surface temperature, relative sliding speed at the die/material interface and the nature of the interface layer are the most significant factors influencing abrasive [ə'breɪsɪv]die wear.(分句法+直译法)腐蚀,通常也称作模具磨损,实际上是材料受压从模具表面剥落的过程。
弹性力学专业英语英汉互译词汇
弹性力学elasticity弹性理论theory of elasticity均匀应力状态homogeneous state of stress 应力不变量stress invariant应变不变量strain invariant应变椭球strain ellipsoid均匀应变状态homogeneous state ofstrain 应变协调方程equation of straincompatibility 拉梅常量Lame constants各向同性弹性isotropic elasticity旋转圆盘rotating circular disk 楔wedge开尔文问题Kelvin problem 布西内斯克问题Boussinesq problem艾里应力函数Airy stress function克罗索夫--穆斯赫利什维Kolosoff-利法Muskhelishvili method 基尔霍夫假设Kirchhoff hypothesis 板Plate矩形板Rectangular plate圆板Circular plate环板Annular plate波纹板Corrugated plate加劲板Stiffened plate,reinforcedPlate 中厚板Plate of moderate thickness 弯[曲]应力函数Stress function of bending 壳Shell扁壳Shallow shell旋转壳Revolutionary shell球壳Spherical shell [圆]柱壳Cylindrical shell 锥壳Conical shell环壳Toroidal shell封闭壳Closed shell波纹壳Corrugated shell扭[转]应力函数Stress function of torsion 翘曲函数Warping function半逆解法semi-inverse method瑞利--里茨法Rayleigh-Ritz method 松弛法Relaxation method莱维法Levy method松弛Relaxation 量纲分析Dimensional analysis 自相似[性] self-similarity影响面Influence surface接触应力Contact stress赫兹理论Hertz theory协调接触Conforming contact滑动接触Sliding contact滚动接触Rolling contact压入Indentation各向异性弹性Anisotropic elasticity颗粒材料Granular material散体力学Mechanics of granular media 热弹性Thermoelasticity超弹性Hyperelasticity粘弹性Viscoelasticity对应原理Correspondence principle 褶皱Wrinkle塑性全量理论Total theory of plasticity 滑动Sliding微滑Microslip粗糙度Roughness非线性弹性Nonlinear elasticity大挠度Large deflection突弹跳变snap-through有限变形Finite deformation格林应变Green strain阿尔曼西应变Almansi strain弹性动力学Dynamic elasticity运动方程Equation of motion准静态的Quasi-static气动弹性Aeroelasticity水弹性Hydroelasticity颤振Flutter弹性波Elastic wave简单波Simple wave柱面波Cylindrical wave水平剪切波Horizontal shear wave竖直剪切波Vertical shear wave 体波body wave无旋波Irrotational wave畸变波Distortion wave膨胀波Dilatation wave瑞利波Rayleigh wave等容波Equivoluminal wave勒夫波Love wave界面波Interfacial wave边缘效应edge effect塑性力学Plasticity可成形性Formability金属成形Metal forming耐撞性Crashworthiness结构抗撞毁性Structural crashworthiness 拉拔Drawing破坏机构Collapse mechanism 回弹Springback挤压Extrusion冲压Stamping穿透Perforation层裂Spalling塑性理论Theory of plasticity安定[性]理论Shake-down theory运动安定定理kinematic shake-down theorem静力安定定理Static shake-down theorem 率相关理论rate dependent theorem 载荷因子load factor加载准则Loading criterion加载函数Loading function加载面Loading surface塑性加载Plastic loading塑性加载波Plastic loading wave简单加载Simple loading比例加载Proportional loading 卸载Unloading卸载波Unloading wave冲击载荷Impulsive load阶跃载荷step load脉冲载荷pulse load极限载荷limit load中性变载nentral loading拉抻失稳instability in tension 加速度波acceleration wave本构方程constitutive equation 完全解complete solution名义应力nominal stress过应力over-stress真应力true stress等效应力equivalent stress流动应力flow stress应力间断stress discontinuity应力空间stress space主应力空间principal stress space静水应力状态hydrostatic state of stress 对数应变logarithmic strain工程应变engineering strain等效应变equivalent strain应变局部化strain localization应变率strain rate应变率敏感性strain rate sensitivity 应变空间strain space有限应变finite strain塑性应变增量plastic strain increment 累积塑性应变accumulated plastic strain 永久变形permanent deformation内变量internal variable应变软化strain-softening理想刚塑性材料rigid-perfectly plasticMaterial 刚塑性材料rigid-plastic material理想塑性材料perfectl plastic material 材料稳定性stability of material 应变偏张量deviatoric tensor of strain 应力偏张量deviatori tensor of stress 应变球张量spherical tensor of strain 应力球张量spherical tensor of stress 路径相关性path-dependency线性强化linear strain-hardening应变强化strain-hardening随动强化kinematic hardening各向同性强化isotropic hardening强化模量strain-hardening modulus幂强化power hardening 塑性极限弯矩plastic limit bendingMoment 塑性极限扭矩plastic limit torque弹塑性弯曲elastic-plastic bending 弹塑性交界面elastic-plastic interface 弹塑性扭转elastic-plastic torsion粘塑性Viscoplasticity非弹性Inelasticity理想弹塑性材料elastic-perfectly plasticMaterial 极限分析limit analysis极限设计limit design极限面limit surface上限定理upper bound theorem上屈服点upper yield point下限定理lower bound theorem下屈服点lower yield point界限定理bound theorem初始屈服面initial yield surface后继屈服面subsequent yield surface屈服面[的]外凸性convexity of yield surface 截面形状因子shape factor of cross-section沙堆比拟sand heap analogy 屈服Yield 屈服条件yield condition屈服准则yield criterion屈服函数yield function屈服面yield surface塑性势plastic potential 能量吸收装置energy absorbing device 能量耗散率energy absorbing device 塑性动力学dynamic plasticity 塑性动力屈曲dynamic plastic buckling 塑性动力响应dynamic plastic response 塑性波plastic wave运动容许场kinematically admissibleField 静力容许场statically admissibleField 流动法则flow rule速度间断velocity discontinuity滑移线slip-lines滑移线场slip-lines field移行塑性铰travelling plastic hinge 塑性增量理论incremental theory ofPlasticity米泽斯屈服准则Mises yield criterion 普朗特--罗伊斯关系prandtl- Reuss relation 特雷斯卡屈服准则Tresca yield criterion洛德应力参数Lode stress parameter莱维--米泽斯关系Levy-Mises relation亨基应力方程Hencky stress equation赫艾--韦斯特加德应力空Haigh-Westergaard 间stress space洛德应变参数Lode strain parameter德鲁克公设Drucker postulate盖林格速度方程Geiringer velocityEquation结构力学structural mechanics结构分析structural analysis结构动力学structural dynamics拱Arch三铰拱three-hinged arch抛物线拱parabolic arch圆拱circular arch穹顶Dome空间结构space structure空间桁架space truss雪载[荷] snow load风载[荷] wind load土压力earth pressure地震载荷earthquake loading弹簧支座spring support支座位移support displacement支座沉降support settlement超静定次数degree of indeterminacy机动分析kinematic analysis结点法method of joints截面法method of sections结点力joint forces共轭位移conjugate displacement影响线influence line三弯矩方程three-moment equation单位虚力unit virtual force刚度系数stiffness coefficient柔度系数flexibility coefficient力矩分配moment distribution力矩分配法moment distribution method 力矩再分配moment redistribution分配系数distribution factor矩阵位移法matri displacement method 单元刚度矩阵element stiffness matrix 单元应变矩阵element strain matrix总体坐标global coordinates贝蒂定理Betti theorem高斯--若尔当消去法Gauss-Jordan eliminationMethod 屈曲模态buckling mode复合材料力学mechanics of composites复合材料composite material 纤维复合材料fibrous composite单向复合材料unidirectional composite泡沫复合材料foamed composite颗粒复合材料particulate composite 层板Laminate夹层板sandwich panel正交层板cross-ply laminate斜交层板angle-ply laminate 层片Ply多胞固体cellular solid 膨胀Expansion压实Debulk劣化Degradation脱层Delamination脱粘Debond纤维应力fiber stress层应力ply stress层应变ply strain层间应力interlaminar stress比强度specific strength强度折减系数strength reduction factor 强度应力比strength -stress ratio 横向剪切模量transverse shear modulus 横观各向同性transverse isotropy正交各向异Orthotropy剪滞分析shear lag analysis短纤维chopped fiber长纤维continuous fiber纤维方向fiber direction纤维断裂fiber break纤维拔脱fiber pull-out纤维增强fiber reinforcement致密化Densification最小重量设计optimum weight design 网格分析法netting analysis混合律rule of mixture失效准则failure criterion蔡--吴失效准则Tsai-W u failure criterion 达格代尔模型Dugdale model断裂力学fracture mechanics概率断裂力学probabilistic fractureMechanics格里菲思理论Griffith theory线弹性断裂力学linear elastic fracturemechanics, LEFM弹塑性断裂力学elastic-plastic fracturemecha-nics, EPFM 断裂Fracture 脆性断裂brittle fracture解理断裂cleavage fracture蠕变断裂creep fracture延性断裂ductile fracture晶间断裂inter-granular fracture 准解理断裂quasi-cleavage fracture 穿晶断裂trans-granular fracture 裂纹Crack裂缝Flaw缺陷Defect割缝Slit微裂纹Microcrack折裂Kink椭圆裂纹elliptical crack深埋裂纹embedded crack[钱]币状裂纹penny-shape crack预制裂纹Precrack短裂纹short crack表面裂纹surface crack裂纹钝化crack blunting裂纹分叉crack branching裂纹闭合crack closure裂纹前缘crack front裂纹嘴crack mouth裂纹张开角crack opening angle,COA 裂纹张开位移crack opening displacement,COD裂纹阻力crack resistance裂纹面crack surface裂纹尖端crack tip裂尖张角crack tip opening angle,CTOA裂尖张开位移crack tip openingdisplacement, CTOD裂尖奇异场crack tip singularityField裂纹扩展速率crack growth rate稳定裂纹扩展stable crack growth定常裂纹扩展steady crack growth亚临界裂纹扩展subcritical crack growth 裂纹[扩展]减速crack retardation 止裂crack arrest 止裂韧度arrest toughness断裂类型fracture mode滑开型sliding mode张开型opening mode撕开型tearing mode复合型mixed mode撕裂Tearing 撕裂模量tearing modulus断裂准则fracture criterionJ积分J-integralJ阻力曲线J-resistance curve断裂韧度fracture toughness应力强度因子stress intensity factor HRR场Hutchinson-Rice-RosengrenField 守恒积分conservation integral 有效应力张量effective stress tensor 应变能密度strain energy density 能量释放率energy release rate内聚区cohesive zone塑性区plastic zone张拉区stretched zone热影响区heat affected zone, HAZ 延脆转变温度brittle-ductile transitiontempe- rature 剪切带shear band剪切唇shear lip无损检测non-destructive inspection 双边缺口试件double edge notchedspecimen, DEN specimen 单边缺口试件single edge notchedspecimen, SEN specimen 三点弯曲试件three point bendingspecimen, TPB specimen 中心裂纹拉伸试件center cracked tensionspecimen, CCT specimen 中心裂纹板试件center cracked panelspecimen, CCP specimen 紧凑拉伸试件compact tension specimen,CT specimen 大范围屈服large scale yielding 小范围攻屈服small scale yielding 韦布尔分布Weibull distribution 帕里斯公式paris formula空穴化Cavitation应力腐蚀stress corrosion概率风险判定probabilistic riskassessment, PRA 损伤力学damage mechanics 损伤Damage连续介质损伤力学continuum damage mechanics 细观损伤力学microscopic damage mechanics 累积损伤accumulated damage脆性损伤brittle damage延性损伤ductile damage宏观损伤macroscopic damage细观损伤microscopic damage微观损伤microscopic damage损伤准则damage criterion损伤演化方程damage evolution equation 损伤软化damage softening损伤强化damage strengthening损伤张量damage tensor损伤阈值damage threshold损伤变量damage variable损伤矢量damage vector损伤区damage zone疲劳Fatigue 低周疲劳low cycle fatigue应力疲劳stress fatigue随机疲劳random fatigue蠕变疲劳creep fatigue腐蚀疲劳corrosion fatigue疲劳损伤fatigue damage疲劳失效fatigue failure疲劳断裂fatigue fracture 疲劳裂纹fatigue crack疲劳寿命fatigue life疲劳破坏fatigue rupture疲劳强度fatigue strength 疲劳辉纹fatigue striations 疲劳阈值fatigue threshold 交变载荷alternating load 交变应力alternating stress 应力幅值stress amplitude 应变疲劳strain fatigue应力循环stress cycle应力比stress ratio安全寿命safe life过载效应overloading effect 循环硬化cyclic hardening 循环软化cyclic softening 环境效应environmental effect 裂纹片crack gage裂纹扩展crack growth, crackPropagation裂纹萌生crack initiation 循环比cycle ratio实验应力分析experimental stressAnalysis工作[应变]片active[strain] gage基底材料backing material应力计stress gage零[点]飘移zero shift, zero drift 应变测量strain measurement应变计strain gage应变指示器strain indicator应变花strain rosette应变灵敏度strain sensitivity 机械式应变仪mechanical strain gage 直角应变花rectangular rosette引伸仪Extensometer应变遥测telemetering of strain 横向灵敏系数transverse gage factor 横向灵敏度transverse sensitivity 焊接式应变计weldable strain gage 平衡电桥balanced bridge粘贴式应变计bonded strain gage粘贴箔式应变计bonded foiled gage粘贴丝式应变计bonded wire gage 桥路平衡bridge balancing电容应变计capacitance strain gage 补偿片compensation technique 补偿技术compensation technique 基准电桥reference bridge电阻应变计resistance strain gage 温度自补偿应变计self-temperaturecompensating gage半导体应变计semiconductor strainGage 集流器slip ring应变放大镜strain amplifier疲劳寿命计fatigue life gage电感应变计inductance [strain] gage 光[测]力学Photomechanics光弹性Photoelasticity光塑性Photoplasticity杨氏条纹Young fringe双折射效应birefrigent effect等位移线contour of equalDisplacement 暗条纹dark fringe条纹倍增fringe multiplication 干涉条纹interference fringe 等差线Isochromatic等倾线Isoclinic等和线isopachic应力光学定律stress- optic law主应力迹线Isostatic亮条纹light fringe光程差optical path difference 热光弹性photo-thermo -elasticity 光弹性贴片法photoelastic coatingMethod光弹性夹片法photoelastic sandwichMethod动态光弹性dynamic photo-elasticity 空间滤波spatial filtering空间频率spatial frequency起偏镜Polarizer反射式光弹性仪reflection polariscope残余双折射效应residual birefringentEffect 应变条纹值strain fringe value应变光学灵敏度strain-optic sensitivity 应力冻结效应stress freezing effect 应力条纹值stress fringe value应力光图stress-optic pattern暂时双折射效应temporary birefringentEffect 脉冲全息法pulsed holography透射式光弹性仪transmission polariscope 实时全息干涉法real-time holographicinterfero - metry 网格法grid method全息光弹性法holo-photoelasticity 全息图Hologram全息照相Holograph全息干涉法holographic interferometry 全息云纹法holographic moire technique 全息术Holography全场分析法whole-field analysis散斑干涉法speckle interferometry 散斑Speckle错位散斑干涉法speckle-shearinginterferometry, shearography 散斑图Specklegram白光散斑法white-light speckle method 云纹干涉法moire interferometry [叠栅]云纹moire fringe[叠栅]云纹法moire method 云纹图moire pattern离面云纹法off-plane moire method参考栅reference grating试件栅specimen grating分析栅analyzer grating面内云纹法in-plane moire method 脆性涂层法brittle-coating method条带法strip coating method坐标变换transformation ofCoordinates计算结构力学computational structuralmecha-nics 加权残量法weighted residual method 有限差分法finite difference method 有限[单]元法finite element method 配点法point collocation里茨法Ritz method广义变分原理generalized variationalPrinciple 最小二乘法least square method胡[海昌]一鹫津原理Hu-Washizu principle赫林格-赖斯纳原理Hellinger-ReissnerPrinciple 修正变分原理modified variationalPrinciple 约束变分原理constrained variationalPrinciple 混合法mixed method杂交法hybrid method边界解法boundary solution method 有限条法finite strip method半解析法semi-analytical method协调元conforming element非协调元non-conforming element混合元mixed element杂交元hybrid element边界元boundary element 强迫边界条件forced boundary condition 自然边界条件natural boundary condition 离散化Discretization离散系统discrete system连续问题continuous problem广义位移generalized displacement 广义载荷generalized load广义应变generalized strain广义应力generalized stress界面变量interface variable 节点node, nodal point [单]元Element角节点corner node边节点mid-side node内节点internal node无节点变量nodeless variable 杆元bar element桁架杆元truss element 梁元beam element二维元two-dimensional element 一维元one-dimensional element 三维元three-dimensional element 轴对称元axisymmetric element 板元plate element壳元shell element厚板元thick plate element三角形元triangular element四边形元quadrilateral element 四面体元tetrahedral element曲线元curved element二次元quadratic element线性元linear element三次元cubic element四次元quartic element等参[数]元isoparametric element超参数元super-parametric element 亚参数元sub-parametric element节点数可变元variable-number-node element 拉格朗日元Lagrange element拉格朗日族Lagrange family巧凑边点元serendipity element巧凑边点族serendipity family无限元infinite element单元分析element analysis单元特性element characteristics 刚度矩阵stiffness matrix几何矩阵geometric matrix等效节点力equivalent nodal force 节点位移nodal displacement节点载荷nodal load位移矢量displacement vector载荷矢量load vector质量矩阵mass matrix集总质量矩阵lumped mass matrix相容质量矩阵consistent mass matrix 阻尼矩阵damping matrix瑞利阻尼Rayleigh damping刚度矩阵的组集assembly of stiffnessMatrices载荷矢量的组集consistent mass matrix质量矩阵的组集assembly of mass matrices 单元的组集assembly of elements局部坐标系local coordinate system局部坐标local coordinate面积坐标area coordinates体积坐标volume coordinates曲线坐标curvilinear coordinates静凝聚static condensation合同变换contragradient transformation 形状函数shape function试探函数trial function检验函数test function权函数weight function样条函数spline function代用函数substitute function降阶积分reduced integration零能模式zero-energy modeP收敛p-convergenceH收敛h-convergence掺混插值blended interpolation等参数映射isoparametric mapping双线性插值bilinear interpolation小块检验patch test非协调模式incompatible mode节点号node number单元号element number带宽band width带状矩阵banded matrix变带状矩阵profile matrix带宽最小化minimization of band width 波前法frontal method子空间迭代法subspace iteration method 行列式搜索法determinant search method 逐步法step-by-step method纽马克法Newmark威尔逊法Wilson拟牛顿法quasi-Newton method牛顿-拉弗森法Newton-Raphson method 增量法incremental method初应变initial strain初应力initial stress切线刚度矩阵tangent stiffness matrix 割线刚度矩阵secant stiffness matrix 模态叠加法mode superposition method 平衡迭代equilibrium iteration子结构Substructure子结构法substructure technique 超单元super-element网格生成mesh generation结构分析程序structural analysis program 前处理pre-processing后处理post-processing网格细化mesh refinement应力光顺stress smoothing组合结构composite structure。
孟庆元工程力学专业英语阅读5
转译成谓语
1、主语转译成谓语(以case, need, attention, emphasis, improvement等名词及名词化结构作主语时,常这样处理)
The prevention of certain types of cancer is distinctly within the realm of possibility.
太阳对人的身体和精神都有极大的影响。
转译成表语
1、主语转译成表语 A great contribution of Edison was the carbon microphone. 炭精传声器是爱迪生的一大贡献。
computer.
这个理论在科学上充满了远见卓识,也许可以跟巴 贝奇的计算机原理相提并论。
2、谓语转译成状语
After more experiments, Galileo succeeded in making a much
better telescope.
又做了一些实验之后,伽利略成功地制造了一架好得多的望远镜。
By 1914 Einstein had gained world fame.
1914年爱因斯坦已成了著名的科学家。
转译成状语
1、定语转译成状语
异常的洞察力
It was an amazing piece of scientific clairvoyance, comparable
perhaps to Charles Babbage’s anticipation of the principle of the
3、谓语转译成主语 Gases differ from solids in that the former have greater
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1、应力和应变应力和应变的概念可以通过考虑一个棱柱形杆的拉伸这样一个简单的方式来说明。
一个棱柱形的杆是一个遍及它的长度方向和直轴都是恒定的横截面。
在这个实例中,假设在杆的两端施加有轴向力F,并且在杆上产生了均匀的伸长或者拉紧。
通过在杆上人工分割出一个垂直于其轴的截面mm,我们可以分离出杆的部分作为自由体【如图1(b)】。
在左端施加有拉力P,在另一个端有一个代表杆上被移除部分作用在仍然保存的那部分的力。
这些力是连续分布在横截面的,类似于静水压力在被淹没表面的连续分布。
力的集度,也就是单位面积上的力,叫做应力,通常是用希腊字母,来表示。
假设应力在横截面上是均匀分布的【如图1(b)】,我们可以很容易的看出它的合力等于集度,乘以杆的横截面积A。
而且,从图1所示的物体的平衡,我们可以看出它的合力与力P必须的大小相等,方向相反。
因此,我们可以得出等式(1)可以作为棱柱形杆上均匀应力的方程。
这个等式表明应力的单位是,力除以面积。
当杆被力P拉伸时,如图所示,产生的应力是拉应力,如果力在方向是相反,使杆被压缩,它们就叫做压应力。
使等式(1)成立的一个必要条件是,应力,必须是均匀分布在杆的横截面上。
如果轴向力P作用在横截面的形心处,那么这个条件就实现了。
当力P没有通过形心时,杆会发生弯曲,这就需要更复杂的分析。
目前,我们假设所有的轴向力都是作用在横截面的形心处,除非有相反情况特别说明。
同样,除非另有说明,一般也假设物体的质量是忽略的,如我们讨论图1的杆一样。
轴向力使杆产生的全部伸长量,用希腊字母δ表示【如图1(a)】,单位长度的伸长量,或者应变,可以用等式来决定。
L是杆的总长。
注意应变ε是一个无量纲的量。
只要应变是在杆的长度方向均匀的,应变就可以从等式(2)中准确获得。
如果杆处于拉伸状态,应变就是拉应变,代表材料的伸长或者延长 如果杆处于受压状态,那么应变就是压应变,这也就意味着杆上临近的横截面是互相靠近的。
当材料的应力和应变显示的是线性关系时,也就是线弹性。
这对多数固体材料来说是极其重要的性质,包括多数金属,塑料,木材,混凝土和陶瓷。
处于拉伸状态下,杆的应力和应变间的线性关系可以用简单的等式来表示。
E是比例常数,叫做材料的弹性模量。
注意E和应力有同样的单位。
在英国科学家托马斯·杨(1773 ~ 1829)研究杆的弹性行为之后,弹性模量有时也叫做杨氏模量。
对大多数材料来说,压缩状态下的弹性模量与处于拉伸时的弹性模量的一样的。
2、拉伸应力应变行为一个特殊材料中应力和应变的关系是通过拉伸测试来决定的。
材料的试样通常是圆棒的形式,被安置在测试机上,承受拉力。
当载荷增加时,测量棒上的力和棒的伸长量。
力除以横截面积可以得出棒的应力,伸长量除以伸长发生方向的长度可以得出应变。
通过这种方式,材料的完整应力应变图就可以得到。
图1所示的是结构钢的应力应变图的典型形状,轴向应变显示在水平轴,对应的应力以纵坐标表示为曲线OABCDE。
从O点到A点,应力和应变之间是直接成比例的,图形也是线性的。
过了A点,应力应变间的线性关系就不存在了,因此A点处的应力叫做比例极限。
随着荷载的增加,应变比应力增加的更快,直到在B点,在拉应力没有明显增大的情况下,物体也发生了相当大的伸长。
这种现象叫做材料的屈服,点B处的应力叫做屈服点或者屈服应力。
在区域BC 材料开始具有塑性,棒也开始塑性伸长,伸长量是在比例极限处伸长量的10或者15倍。
在C点,材料开始应变硬化,并且进一步的阻力,阻止载荷的增加。
这样,随着进一步的伸长,应变增加,并且在D点达到最大值,或者极限应变。
过了这一点,棒的拉伸伴随着载荷的减少,试样最后在图上E点断裂。
在棒伸长期间,发生了侧面的收缩,导致棒的横截面积减小。
这个现象在C点之前,对应力应变图没有影响,但是过了这一点,面积的减小对应力的计算值有明显的影响。
棒就会发生明显的颈缩(如图2所示),并且如果颈处狭窄部分的实际横截面积被用于计算ζ,将会发现真实的应力应变曲线是虚线CE。
尽管在极限应力达到之后,棒上的总荷载有实际的减小,这个减小是由于面积的减少,而不是材料强度的减小。
在失效点之前,材料实际经受了应力的增加。
然而,为了多数实用目的,常规的应力应变曲线OABCDE是基于试样最初的横截面积,为设计目的提供了令人满意的信息。
图1的图形,画出来是为了表示应力应变曲线的一般特性。
在应力应变曲线的最初区域,材料表现的既有弹性又有线性。
钢材的应力应变图上的从O到A的区域就是很好的例子。
紧接着大的塑性应变,明显屈服点的出现,对于在今天是很普通的结构化金属——钢材来说稍微有点独特。
铝合金从线性到非线性区域是更渐渐的转变。
在失效之前,钢和许多铝合金承受了更大的应变,所以被归类为易延展的。
另一方面,脆性材料在很低的应变时就失效了。
实例包括陶瓷,铸铁,混凝土,某些金属合金,和玻璃。
3、圆棒的扭转让我们设想一下,一个具有圆形横截面的棒被作用在其末端的力偶扭转(如图1)。
以这种方式加载的棒据称是处于纯扭转。
从考虑对称性可以看出,圆棒的横截面在纵轴方向是作为刚体扭转的,半径依然是直的,横截面是圆形的。
并且,如果棒扭转的总角度比较小的话,棒的长度和半径r都不会改变。
在扭转期间,对应于棒的一端,棒的另一端绕着纵轴会发生扭转。
例如,如果我们把棒的左端看做固定的,那么对应于棒的左端,棒的右端会旋转一个角度。
同时,棒表面的纵向线例如nn,会旋转一个小的角度到位置。
因为扭转,棒表面的矩形单元,例如图中所示的在两个横截面之间相距的单元,被扭转成长菱形。
当一个杆状物承受纯扭转时,扭转角的变化率沿着棒的长度方向是恒定不变的。
这个常数代表单位长度的扭转角,用符合 表示。
这样,我们得出,L是轴的长度。
然后,我们可以得到切应变。
作用在单元边线处的切应力有图1所示的方向。
对于线弹性材料,切应力大小是。
等式(1)(2)把杆状物的应变和应力与单位长度的扭转角联系起来。
杆状物内部的应力表述用的方式类似于用于杆状物表面的表述方式。
因为棒横截面的半径依然是直的,在扭转时没有扭曲,我们看到位于半径为ρ的圆柱体表面的内部单元,是纯剪切并伴随着对应的切应变,应力可以从下述的表达式得出。
这些等式表明,从轴心处切应力和切应变随着径向距离是线性变化的,并且在外表面达到最大值。
作用在横截面的切应力,由等式(3b)给出,伴随着作用在杆状物纵向平面的相等的切应力。
这个结果是从这样一个事实得到的,就是相等的切应力总是存在于相互垂直的平面。
如果材料纵向受剪弱于侧向受剪(例如,木材),受扭杆状物的第一次断裂将会出现在它的纵向表面。
杆状物表面的纯剪切应力的表述等效于,对于杆状物轴扭转45。
的单元上的拉应力和压应力。
如果一种受拉比受剪弱的材料受扭,那么材料将会沿着与轴成45。
的螺旋线处以收缩的方式失效。
通过扭转一支粉笔的方式就可以很容易的演示这种失效。
可以建立施加的扭矩T和产生的扭转角间的关系。
切应力的合力必须静定的等于合扭矩。
作用在单元面积dA上的剪切力是,这个力对于棒轴的力矩是。
在等式(3b)中,力矩等于。
合力矩T是整个横截面上的单元力矩的总和,因此,总和,因此,是圆截面的极惯性矩。
从等式(4)我们可以得到,是单位长度的扭转角,与扭矩T成正比,与乘积,是相反的,是杆的扭转刚度。
4、梁的挠曲一根承受轴横向力的棒叫做梁。
图1中的梁,一端是针状支撑,另一端的滚动支撑,叫做简支梁或者简单的梁。
简支梁的本质特征是在弯曲时梁的两端可以自由转动,但是它不能够横向移动。
另外,梁的一端可以沿轴向自由移动。
一端是嵌入式或者固定,另一端的自由的梁,叫做悬臂梁。
梁的固定端既不可以转动也不可以移动,自由端则可以转动和移动。
梁上的荷载可以分为集中力,例如图1中的力 ,或者分布载荷,可以表述为沿着梁轴单位距离作用单位力。
轴向力 作用于横截面的法向,通过横截面的质心。
剪力??平行于横截面,弯矩 作用于平面梁,被叫做合应力。
剪力、弯矩 和梁上荷载的关系可以表述为。
这个等式表示,在分布载荷(或者没有载荷)作用于梁上时,弯矩的变化率等于剪力的代数值。
如果梁上作用有集中力,那么在集中力作用点剪力处,将会有突变,或者不连续。
作用在梁侧面的载荷将会引起梁的挠曲。
如图 所示,在力 作用前,梁的纵轴是直的。
在弯曲后,梁的轴变成了曲线,表现为曲线,让我们假设xy平面是对称与梁的平面,并且所有的载荷都作用在平面内。
那么曲线,叫做梁的挠曲线,也会在平面内。
从图形的几何形状可以看出,是曲率,等于曲率的半径的倒数。
这样,曲率等于角度在沿着挠曲线测量的长度方面的变换率。
梁挠曲线的基本微分方程可以表述为,是梁从初始位置的挠度。
必须在每个事例中求积分来获得挠度。
这个步骤包括方程的连续积分,作为结果的积分常数从梁的边界条件获得。
应该明白,只有在材料适用于胡克定律并且挠曲线的斜率是很小的时候,方程才是有效。
另一种获得梁挠度的方法是力矩面积法。
这个方法得名于它利用了弯矩图的面积。
当想得到挠度或者梁上一点处的斜率,而不是获得挠曲线的整个方程,这个方法是特别有用的。
作用在横截面上任意一点处的正应力和切应力,可以使用方程,其中 是在横截面中性轴方面的第二力矩(或者惯性矩),Q是梁平面面积的第一力矩(或者静态矩)。
可以看出梁外缘处正应力是最大的,在中性轴处为零,在外缘处切应力为零,在中性轴处经常达到最大。
梁上的剪力V和弯矩M经常随着距离变化,距离规定是从它们作用在梁上的横截面处开始的。
当设计一个梁时,非常想知道梁上所以横截面处和的值,提供这方面信息的一个很简便的方法是画一个表达它们沿着梁轴变化的图。
为了画出图,我们把横截面的位置作为横坐标,把对应的剪力或者弯矩的值作为纵坐标。
这样的图像叫做剪力图或者弯矩图。
图1中的简支梁是静定梁中的一种。
这种梁的特征的它所有的反作用力都是由静力平衡方程决定的。
反作用力的数目多于静力平衡方程数目的梁叫做超静定梁。
对于静定梁,我们可以通过求解静力平衡方程快速获得梁的反作用力。
然而,当梁是超静定时,我们不能仅从静力方面求解解决。
取而代之的是,我们必须考虑梁的挠度,并且获得相容方程作为静力方程的补充。
6、刚体的平衡静力学的主要目标是建立一个基本理论,来管理作用在处于平衡状态的物体上的力。
描述阻止物体移动的力的一个手段是自由体受力图,它使物体从周围的事物中隔离出来。
在受力图中,我们展示了施加在物体上的所有力,记住牛顿第三定律告诉我们的,力是物体之间相互作用的结果。
构建受力图的过程帮助我们理解系统的参数是很重要的。
构建自由体受力图的部分任务的为了检查支撑结构,以便我们可以推导出应用在物体上的什么类型的力。
这些力有时叫做约束力,因为它们代表支撑结构约束物体移动的方式。
对这些力的另一个术语是反作用力,因为它们代表支撑结构对物体移动趋势做出反应的方式。