工程力学专业外语.ppt

BASIC TYPES OF DEFORMATIONS OF ROD,Bear; Bearing stress,normal stress,Shear force,tensile force,compressive force,Shearing stress,Shear force,Bending moment,normal stress,Torque,Shearing stress,Shearing stress,EA -the axial rigidity of the rod in tension or compression,E -elastic modulus,G - the modulus of rigidity or shear modulus,IP Polar moment of inertia.,Wt section factor modulus in torsion,Iz Section moment of inertia.,Wz section modulus,1. Types of support,2. Types of load,couples forces,3. Shear forces and bending moments in a cantilever beam,Set of elements ( or members) x,y,z,intersection,union,There is a or there exists,function f of x,dee x, differential x,the first derivative of y with respect to x,the second derivative of y with respect to x,the first partial derivative of y with respect to x,nabla; vector differential operator,Gradient of f,Divergence of V,1. Stress and strain are related terms used to define the intensity of internal reactive forces in a deformed body and associated unit change of dimension, shape, or volume by externally applied forces.,2. Yielding strength is the stress accompanying a specified permanent plastic strain, which is considered as not having impaired useful elastic behavior and which represents the practical elastic strength for materials having a gradual knee in the stress- strain curve.,3. Ultimate strength defines the maximum resistance to tensile, compressive, or shearing forces, expressed either as a total load-producing fracture as in the case of a rope or cable, the maximum stress developed prior to fracture, or the stress accompanying some limiting deformation.,4. Ultimate tensile strength is the maximum nominal tensile stress developed during increasing-load application, calculated from maximum applied load and original unstrained sectional area.,5. Those materials developing large elongation reach maximum load resistance prior to fracture, which occurs at a locally reduced section.,6. The strain energy per unit volume stored in the material when fractured is represented by the total area under the stress-straincurve and it called the toughness.,Elastic Range: Linear elastic:, Nonlinear elastic:,Plastic Range: Yield point, Yield strength Ultimate strength,力学 mechanics 牛顿力学 Newtonian mechanics 经典力学 classical mechanics 静力学 statics 运动学 kinematics 动力学 dynamics 动理学 kinetics 宏观力学 macroscopic mechanics, macromechanics 细观力学 mesomechanics 微观力学 microscopic mechanics, micromechanics 一般力学 general mechanics 固体力学 solid mechanics 流体力学 fluid mechanics 理论力学 theoretical mechanics 应用力学 applied mechanics 工程力学 engineering mechanics 实验力学 experimental mechanics 计算力学 computational mechanics 理性力学 rational mechanics 物理力学 physical mechanics 地球动力学 geodynamics 分析力学 analytical 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,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 本构关系 constitutive relation,Acceleration， velocity (速度), speed (速率), vector,Assumption, hypothesis, postulate,Dynamics= kinematics (运动学) + kinetics（动力学）,Rectangular, square, parallelogram, rhombus（菱形），diamond（菱形）,Pentagon（五边形，五角形）hexagon（六边形）polygon（多边形）,Quadrangular 四棱柱，triangular prism（三棱柱）,cylinder（圆柱体）column-shaped things（柱状物） pillar; post; column（柱子）,cone（锥体），sphere; globe（球） triangular pyramid（三棱锥）rectangular pyramid（四棱锥）,oval; oval-shaped; ellipse; ellipsoid（椭圆）,trigonometry, algebra, and differential and integral calculus,Radius of curvature curvature (Greek kappa),neutral surface neutral axis, 0 elongation tension,Iz the MOMENT OF INERTIA of the cross-sectional area; the area MOMENT OF INERTIA; or second moment of area.,EI - the structural rigidity,boundary conditions.,NEWTONS LAW OF MOTION,Sir Isaac Newton, in his treatise the principia, announced three famous laws that describe the motion of a particles.,First Law: For every action, there is an equal and oppositely reaction, or the mutual forces exerted by two particles on each other are always equal and oppositely directed.,Second Law: Acceleration of a particle is proportional to the force that acts on the particle and inversely proportional to the mass of the particle. F (force) = m (mass) a (acceleration),Third Law Every force (action) is accompanied by an equal and opposite force (reaction) Action-reaction,Modal analysis 模态分析,1.Finite element modal analysis of ground driving system for progressing cavity pump; 螺杆泵井地面驱动系统的有限元模态分析 2.Fluid-solid coupling modal analysis on G70B train oil tank; G70B列车油罐液固耦合模态分析 3.Experimental Modal Analysis on Back Cover of Computer; 基于模态分析对电脑显示器后壳的研究,mode analysis 模态分析,1.Mode analysis of finite element on a crankshaft by using APDL language to set up Three-dimensional model; APDL参数化三维建模的曲轴有限元模态分析 2.Emulation and mode analysis of the long-span steel arch bridge; 大跨度钢拱桥的仿真与模态分析 3.Application of mode analysis in hydraulic turbine; 模态分析在水轮机中的应用,Modal analysis 模拟分析法,1.The Application of ANSYS in Model Analysis of CNC Lathe; ANSYS在数控机床模态分析中的应用 2.Finite element model analysis of slingshot substructure of ZJ70D drilling rig; ZJ70D型钻机双升式底座有限元模态分析 3.The finite element modeling and model analysis of the teleconsulting vehicle compartment; 远程会诊车车厢有限元建模与模态分析,modality analysis 模式分析,1.Finite element modality analysis of single cylinder crankshaft crack based on CAD modeling; 基于CAD建模的单缸曲轴裂纹的有限元模态分析 2.Restraint modality analysis on spatial mechanical arm; 空间机械臂约束模态分析 3.Treatment of hinge link in finite element modality analysis of flexible bodied mechanism; 柔体机构有限元模态分析中铰链联接的处理,mode shape analysis 阵型分析,1.On the basis of mode shape analysis, dynamic analysis, ANN, ANFIS and random vibration theory, vehicle frame can be dealt with by the dynamic analysis, manufacture performance parameters for the frame can be analyzed online, and the quality of the frame can be verified and forecasted.,本文以模态分析、动态分析、ANN（人工神经网络）、ANFIS（自适应模糊推理系统 ）理论及随机振动理论等作为基础,对汽车车架在试车场环境下进行动态分析以及汽车车架制造性能参数在线分析、质量检验、预测与控制,Intermolecular Cohesive Compactness Mechanical analysis Intermolecular cohesion Thermodynamics Elastic energy Surface tension Curvature Specific weight 比重（量） Specific volume 比容 Specific gravity 比重（力） Bulk modulus 体积模量,FLUID PROPERITES,FLUID PROPERITES,1.matter exists in two states - the solid and the fluid, the fluid state being commonly divided into the liquid and gaseous states.,物质有两种状态 - 固体和流体， 流体通常又分为液体和气体,2. Solids differ from liquids and liquids from gases in the spacing and latitude of motion of their molecules, these variables being large in a gas, smaller in a liquid, and extremely small in a solid.,在他们的分子间距与分子运动范围方面，固体不同于液体，液体又不同于气体，这些变量在气体较大，液体中较小而固体中最小。,FLUID PROPERITES,3.These fundamental facts account for the familiar compactness and rigidity of form possessed by solids, the ability of liquid molecules to move freely within a liquid mass, and the capacity of gases to fill completely the containers in which they are placed, while a liquid has a definite volume and a well defined surface.,这些基本事实说明固体具有熟知的紧密性和形状的刚性，液体分子在一液体团中的自由运动能力和气体完全充满所盛容器的能力，而液体有一一定的体积和一明确的表面。,4.All fluids can be compressed by the application of pressure, elastic energy being stored in the process; assuming perfect energy conversions, such as compressed volumes of fluids will expand to their original volumes when the applied pressure is released.,一切流体通过施加压强均可被压缩，在这过程中，弹性能被储存起来，假定能量转换是完全的，当所施压强移去后流体的这种被压体积会膨胀至它原来的体积。,FLUID PROPERITES,5.Thus fluids are elastic media, and it is customary in engineering to summarize this property by defining a modulus of elasticity as is done for solid elastic materials such as steel.,这样，流体是弹性介质，如同固体弹性材料所作那样，比如钢。通常在工程中通过定义一弹性模量来概括这一性质。,6.Also relevant to the use of equation(12) is the observed fact that the velocity at a solid boundary is zero, that is , there is no ”slip” between fluid and solid for all fluids that can be treated as a continuum.,在固体边界处速度为零 - 即在流体与固体之间， 一切可以当做连续介质看待的流体均不存在“滑动” - 这一观察到的事实与使用方程（12）有关。,FLUID PROPERITES,7.In gases， where intermolecular cohesion is usually negligible, the shear stress, , between moving layers of fluid results from an exchange of momentum between these layers brought about by molecular agitation normal to the general direction of motion.,8.In fact, treating the supporting tension is an analogy used widely in theoretical treatment of surface tension problems.,事实上，将表面当成一种承受张力的薄膜是理论处理表面张力问题是广泛使用的一种类比法。,在气体中，分子间的内聚力通常可以忽略，运动流体层之间的剪应力 来自这些层之间的动量交换， 这种交换是由于分子在垂直于总运动方向的扰动引起的。,The fluid enters the boundary layer and loses much of its kinetic energy, of which a small part is conduced away although most is converted into thermal energy. 流体进入边界层同时失去了它的许多功能，动能的一小部分被传导走了，虽然它的大部分被转换为热能。,Constrained by the duct walls into a no-gowth condition, the velocity profile settles into a fully developed shape which is independent of the streamwise coordinate. 速度轮廓线受通道壁的约束成为无法生长的情况，它演变成了与流向坐标无关的充分发展形状。,All solid surface interact with a viscous fluid flow because of a no-slip condition, a physical requirement that the fluid and solid have equal velocities at their interface. 由于物理上的无滑移条件要求，即在流体与固壁的界面处有相同的速度，一切固壁表面与粘性流体流动相互影响。,Boudinary-layer flow 边界层流动； inviscid 无粘性的； viscous 粘性； newtonian fluid 牛顿流体； constrained 被约束的；,Many terms may then be dropped from basic Navier-Stokes equations, and the resulting boundary-layer equations eliminate pressure as a variable and solve merely for u and v by extending downstream between the wall, where no-slip obtains, and the inviscid outer stream, where U(x) is assumed directly related to the pressure P(x) by the Bernoulli relation（3）. 省去了Navier-Stokes方程组中的许多项和所得到的边界层方程组不再把压强作为一变量；同时在下游的固壁与外部无粘性流之间的范围内仅对u和v求解。在固壁处有无滑移条件，而在外部无粘流处，假定速度U(x)与压强p(x)通过伯努利关系式（3）直接联系。,Anchor 锚 Dam 水坝； ramp， incline，slope斜坡 Placement 方位； supervisor; advisor; tutor导师 Computer-aid-design 计算机辅助设计； Structural engineering 结构工程； pipeline engineering 管道工程；,CIVIL ENGINEERING,CIVIL ENGINEERING,1.Enviormental specialists study the projects impact on the local area; the potential for air and groundwater pollution, the projects impact on local animal and plant life, and how the project can be designed to meet government requirements aimed at protecting the environment.,环境专家研究工程项目对本地区的冲击，即空气与地下水被污染的潜在可能性，工程项目对本地区动物与植物生命的冲击，和如何设计工程项目使其满足政府对保护环境的要求。,2. Supervising and coordinating the work of these civil engineer specialists, from beginning to end of the project, are the construction management specialists.,To impact on - 对的冲击； To meet the requirements of - 满足.的要求； To aim at doing - 目的在于,CIVIL ENGINEERING,3. Based on information supplied by the other specialists, construction management civil engineers estimate quantities and costs of materials and labor, schedule all work, order materials and equipment for the job, hire contractors and subcontractors, and perform other supervisory work to ensure the project is completed on time and as specified.,以其它专家所提供的信息为基础，施工管理土木工程师估计材料与劳力的数量和价格，安排一切工作计划，订购工作所需的材料与设备，雇佣承包商和进行其他监督工作以确保工程项目能按时按规定的完成。,4. Using computers, structural engineers determine the forces a structure must resist, its own weight, wine and hurricane forces, temperature changes that expand or contract construction materials, and earthquakes.,结构工程师使用计算机确定一结构所必需抵抗的力，即结构本身的重量，风力与飓风力，温度变化引起建筑材料的膨胀或收缩和地震。,CIVIL ENGINEERING,5. Their projects help prevent floods, supply water for cities and for irrigation, manage and control rivers and water runoff, and maintain beaches and other waterfront facilities.,Runoff - 径流，流走之物； Waterfront- 滨水区,6. They coordinate the activities of virtually everyone engaged in the work: the surveyors; workers who lay out and construct the temporary roads and ramps, excavate for the foundation, build the forms and pour the concrete; and workers who build the steel frame-work.,他们几乎协调每一参加工作人员的活动； 这包括测量员；设计与建造临时道路与斜坡，挖掘地基，建造外形与倾注水泥的工人；和建造钢筋骨架的工人。,他们的工程项目帮助防止洪水，供给城市和灌溉用水，管理与控制江河及水的流失，并维护海滩和其他沿岸设施。,CIVIL ENGINEERING,7. Radio signals from satellites, scanned by laser and sonic beams, are converted to maps to provide very accurate measurements for boring tunnels, building highways and dams, plotting flood control and irrigation projects, locating subsurface geologic formations that may affect a construction project and a host of other building uses.,通过激光束与声束，可把热早地球卫星来的无线电信号转变为图像，一边为开凿隧道建造公路与堤坝，为计划洪水控制与灌溉工程，为确定向施工计划的地下地质构造和为其他许多建筑用途提供很准确的测量结果。,To convert A to B - 把A转换成B； To provide A for B - 为B提供A；,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,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,模态叠加法 mode superposition method 平衡迭代 equilibrium iteration,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,岩石力学 rock mechanics 原始岩体应力 virgin rock stress 构造应力 tectonic stress 三轴压缩试验 three-axial compression test 三轴拉伸试验 three-axial tensile test 三轴试验 triaxial test 岩层静态应力 lithostatic stress 地压强 geostatic pressure 土力学 soil mechanics,弹性力学 elasticity,应力不变量 stress invariant 应变不变量 strain invariant 应变椭球 strain ellipsoid 应变协调方程 equation of strain compatibility 拉梅常量 Lame constants 各向同性弹性 isotropic elasticity 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,各向异性弹性 Anisotropic elasticity 热弹性 Thermoelasticity 超弹性 Hyperelasticity 粘弹性 Viscoelasticity,非线性弹性 Nonlinear elasticity 大挠度 Large deflection 简单加载 Simple loading 比例加载 Proportional loading 卸载 Unloading 本构方程 constitutive equation 等效应力 equivalent stress 等效应变 equivalent strain 各向同性强化 isotropic hardening 强化模量 strain-hardening modulus 理想弹塑性材料 elastic-perfectly plastic Material,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,节点 node, nodal point 节点号 node number 单元 Element 单元号 element number 角节点 corner node 边节点 mid-side node 内节点 internal node 无节点变量 nodeless variable,FDM-Finite Difference Methods(有限差分法),The domain of solution of the given PDE is first subdivided (细分) by a net with a finite number of mesh points (网格点). The derivative at each point is then replaced by a finite difference approximation. Alternatively, one can visualize this discretization (离散化) procedure as the replacement of the solution of the PDE with an interpolating (插入，插入值) polynomial (多项式) and differentiation of this polynomial.,FEM- Finite-element method FEM employs subdivision of the solution domain into many smaller shapes, such as triangles and quadrangles and use approximation theory（近似理论） to quantize (量化) behavior on each finite element（有限单元）. Using a variational principle（变分原理） or a weighted-residual method（加权残余法）, Those local equations are collected together to form a global system of ordinary differential（微分） or algebraic（代数） equations including a proper accounting of boundary conditions. The nodal values of the dependent variables are determined from solution of this matrix equation system.,BEMBoundary Element Method,The fundamental motivation behind boundary equation methods, BIEM ( boundary element method) is the reduction of the dimensionality (维度) of the problem. Thus we simplify a problem from one involving area integration to one involving line integration. In general, the number of equations derived from a formulation will be fewer than in the case of an interior method (内部法). In contrast to the sparse matrices (稀疏矩阵) encountered in other methods, however the BIEM-generated (边界积分方程所生成的) matrices are full.,Other methods,Various alternatives to the finite-difference approach are available, including integral approaches (积分方法) such as moment methods (力矩法), last square technique (最小二乘法), Galerkin techniques (伽辽金法), and Rayleigh-Ritz variational formulations (瑞利-瑞兹变分法). Each of them can be applied on a subdomain (子域) of a continuum (连续介质) or ever the entire region of interest. The subdomain approach may be a finite-element or spectral method (谱法) in the classical sense, depending on the function employed. A spectral method solves a problem only in spectral space (谱空间) or transformed space (变换空间).,Introduction to Finite Element Method There are two version of FEM 1.Flexibility Method or Force Method: 2.Stiffness Method or Displacement Method. The set of equations in the stiffness method are the equilibrium equations relating displacements of points. Rayleigh-Ritz is an approximate method based on energy principle by which we can obtain equilibrium equations in matrix form,Rayleigh-Ritz method is an approximate method of finding displacements that is based on the theorem of minimum potential energy. The method is restricted to conservative systems that may be linear or non-linear.,Minimum Potential Energy The theorem of minimum potential energy can be stated as: Of all the kinematically admissible displacement functions the actual displacement function is the one that minimizes the potential energy function at stable equilibrium.,Relative merits（相对优点）,Relative merit Parabolic problem Algorithm算法 Collocation theory Singularity Although the approximating algebraic equations arising from finite element pr