利用有限元模型对钻机进行动态分析的研究外文文献翻译、中英文翻译

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摩擦系数和井底钻压的有限元分析

Calculation of friction coefficient and downhole weight on bit withfinite element analysis of drillstring摩擦系数和井底钻压的有限元分析摘要：通过实时计算钻柱与井壁之间的摩擦系数，可用于识别可能发生的井眼清洗问题，卡管，压差卡钻，地层变化和泥浆润滑等问题。

正确的计算和分析井底钻压(DWOB)对钻井作业和优化非常重要。

本文介绍了一种实用的有限元分析（FEA）模型和程序，在钻井作业期间，可以模拟钻柱的工作行为。

鉴于大钩载荷，井眼几何形状和其他一些钻井参数，有限元分析程序可以在后台自动计算钻柱和套管或地层之间的摩擦因子或系数。

本文开发的程序也可以被用来计算在不同的钻探工作模式如直井，定向井，水平井和任何复杂井眼轨迹中的实际井底钻压（DWOB）。

基于摩擦系数，使用有限元分析程序来获得实际井底钻压（DWOB）1 介绍扭矩和磨阻作为辅助钻井实时分析的一个重要的参数。

为了计算扭矩和摩阻，摩擦系数必须已知。

实时计算摩擦系数是用来确定可能发生的井眼清洗问题，卡管，压差卡钻，地层变化和泥浆润滑等问题。

下套管或裸眼井的摩擦系数通常是通过实际数据计算。

1983，Johancsik研制的一种定向井钻柱扭矩和磨阻模型。

该模型假定滑动摩擦力由井眼与钻柱接触引起的。

钻柱与井壁的接触力由钻柱的自重和张力决定。

摩擦系数的测定是该模型的基础。

现场数据进行重新计算滑动摩擦系数。

摩擦系数是扭矩和阻力模型的一个重要参数，因为它是表面相互作用模型的核心。

适用于任何情况下的摩擦系数是一个多因素的函数，包括流体类型，组成和润滑性，形成型，套管和钻杆接头材料和表面粗糙度。

当重要的部分，可能需要使用两个或两个以上的摩擦因素，一种用于套管钻柱和一个用于地层中钻柱。

一种新型的三维井筒摩阻扭矩模型在钻水平井和大位移井被提出。

钻头的性能直接影响到整个钻井性能。

英译汉-有限元方法的一般描述

General Description of the Finite Element Method In the finite element method, the actual continuum or body of matter like solid, liquid or gas is represented as an assemblage of subdivisions called finite elements.These elements are considered to be interconnected at specified joints which are called nodes or nodal points.The nodes usually lie on the element boundaries where adjacent elements are considered to be connected. Since the actual variation of the field variable (like displacement,stress,temperature,pressure or velocity) inside the continuum is not known, we assume that the variation of the field variable inside a finite element can be approximated by a simple function.These approximating functions (also called interpolation models) are defined in terms of the field variable. By solving the field variable will be known. Once these are known, the approximating functions define the field variable throughout the assemblage of elements.The solution of a general continuum problem by the finite element method always follows an orderly step-and-step process. With reference to static structural problems, the step-by-step procedure can be stated as follows:Step(i) : Discretization of the structureThe first step in the finite element method is to divide the structure or solution region into subdivisions or element. Hence the structure that is being analyzed has to be modeled with suitable finite elements. Thenumber, type, size and arrangement of the elements have to be decided.Step(ii) : Selection of a proper interpolation or displacement model Since the displacement solution of a complex structure under any specified load conditions cannot be predicted exactly, we assume some suitable solution within an element to approximate the unknown solution. The assumed solution must be simple from computational point of view, but it should satisfy certain convergence requirements. In general, the solution or the interpolation model is taken in the form of a polynomial.Step(iii) : Derivation of element stiffness matrices and load vectors From the assumed displacement model, the stiffness matrix [）（e K ]and the load vector (e)p , of element “e ” are to be derived by usingeither equilibrium conditions or a suitable variational principle.Step(iv) : Assemblage of element equations to obtain the overall equilibrium equationsSince the structure is composed of several finite elements, the individual elements, the individual element stiffness matrices and load vectors are to be assembled in a suitable manner and the overall equilibrium equations have to be formulated as[]P K =Φ For linear problems, the vector Φ can be solved very easily. But fornonlinear problems, the solution has to be obtained in a sequence of steps, each step involving the modification of the stiffness matrix [K] and/or theload vector P .From the known nodal displacements , if required, the element strainsand stresses can be computed by using the necessary equations of solid or structural mechanics.The terminology used in the above six steps has to be modified if we want to extend the concept to other fields. For example, we have to use the term continuum or domain in place of structure ，field variable in place of displacement, characteristic matrix in place of stiffness matrix, and element resultants in place of element strains.有限元方法的一般描述在有限元方法中，固体物质的实际连续体或主体如固体，液体或气体作为细分的组合称为有限元素。

有限元分析中英文对照资料

The finite element analysisFinite element method, the solving area is regarded as made up of many small in the node connected unit (a domain), the model gives the fundamental equation of sharding (sub-domain) approximation solution, due to the unit (a domain) can be divided into various shapes and sizes of different size, so it can well adapt to the complex geometry, complex material properties and complicated boundary conditionsFinite element model: is it real system idealized mathematical abstractions. Is composed of some simple shapes of unit, unit connection through the node, and under a certain load.Finite element analysis: is the use of mathematical approximation method for real physical systems (geometry and loading conditions were simulated. And by using simple and interacting elements, namely unit, can use a limited number of unknown variables to approaching infinite unknown quantity of the real system.Linear elastic finite element method is a ideal elastic body as the research object, considering the deformation based on small deformation assumption of. In this kind of problem, the stress and strain of the material is linear relationship, meet the generalized hooke's law; Stress and strain is linear, linear elastic problem boils down to solving linear equations, so only need less computation time. If the efficient method of solving algebraic equations can also help reduce the duration of finite element analysis.Linear elastic finite element generally includes linear elastic statics analysis and linear elastic dynamics analysis from two aspects. The difference between the nonlinear problem and linear elastic problems:1) nonlinear equation is nonlinear, and iteratively solving of general;2) the nonlinear problem can't use superposition principle;3) nonlinear problem is not there is always solution, sometimes even no solution. Finite element to solve the nonlinear problem can be divided into the following three categories:1) material nonlinear problems of stress and strain is nonlinear, but the stress and strain is very small, a linear relationship between strain and displacement at this time, this kind of problem belongs to the material nonlinear problems. Due to theoretically also cannot provide the constitutive relation can be accepted, so, general nonlinear relations between stress and strain of the material based on the test data, sometimes, to simulate the nonlinear material properties available mathematical model though these models always have their limitations. More important material nonlinear problems in engineering practice are: nonlinear elastic (including piecewise linear elastic, elastic-plastic and viscoplastic, creep, etc.2) geometric nonlinear geometric nonlinear problems are caused due to the nonlinear relationship between displacement. When the object the displacement is larger, the strain and displacement relationship is nonlinear relationship. Research on this kind of problemIs assumes that the material of stress and strain is linear relationship. It consistsof a large displacement problem of large strain and large displacement little strain. Such as the structure of the elastic buckling problem belongs to the large displacement little strain, rubber parts forming process for large strain.3) nonlinear boundary problem in the processing, problems such as sealing, the impact of the role of contact and friction can not be ignored, belongs to the highly nonlinear contact boundary. At ordinary times some contact problems, such as gear, stamping forming, rolling, rubber shock absorber, interference fit assembly, etc., when a structure and another structure or external boundary contact usually want to consider nonlinear boundary conditions. The actual nonlinear may appear at the same time these two or three kinds of nonlinear problems.Finite element theoretical basisFinite element method is based on variational principle and the weighted residual method, and the basic solving thought is the computational domain is divided into a finite number of non-overlapping unit, within each cell, select some appropriate nodes as solving the interpolation function, the differential equation of the variables in the rewritten by the variable or its derivative selected interpolation node value and the function of linear expression, with the aid of variational principle or weighted residual method, the discrete solution of differential equation. Using different forms of weight function and interpolation function, constitute different finite element methods. 1. The weighted residual method and the weighted residual method of weighted residual method of weighted residual method: refers to the weighted function is zero using make allowance for approximate solution of the differential equation method is called the weighted residual method. Is a kind of directly from the solution of differential equation and boundary conditions, to seek the approximate solution of boundary value problems of mathematical methods. Weighted residual method is to solve the differential equation of the approximate solution of a kind of effective method.Hybrid method for the trial function selected is the most convenient, but under the condition of the same precision, the workload is the largest. For internal method and the boundary method basis function must be made in advance to meet certain conditions, the analysis of complex structures tend to have certain difficulty, but the trial function is established, the workload is small. No matter what method is used, when set up trial function should be paid attention to are the following: (1) trial function should be composed of a subset of the complete function set. Have been using the trial function has the power series and trigonometric series, spline functions, beisaier, chebyshev, Legendre polynomial, and so on.(2) the trial function should have until than to eliminate surplus weighted integral expression of the highest derivative low first order derivative continuity. (3) the trial function should be special solution with analytical solution of the problem or problems associated with it. If computing problems with symmetry, should make full use of it. Obviously, any independent complete set of functions can be used as weight function. According to the weight function of the different optionsfor different weighted allowance calculation method, mainly include: collocation method, subdomain method, least square method, moment method and galerkin method. The galerkin method has the highest accuracy.Principle of virtual work: balance equations and geometric equations of the equivalent integral form of "weak" virtual work principles include principle of virtual displacement and virtual stress principle, is the floorboard of the principle of virtual displacement and virtual stress theory. They can be considered with some control equation of equivalent integral "weak" form. Principle of virtual work: get form any balanced force system in any state of deformation coordinate condition on the virtual work is equal to zero, namely the system of virtual work force and internal force of the sum of virtual work is equal to zero. The virtual displacement principle is the equilibrium equation and force boundary conditions of the equivalent integral form of "weak"; Virtual stress principle is geometric equation and displacement boundary condition of the equivalent integral form of "weak". Mechanical meaning of the virtual displacement principle: if the force system is balanced, they on the virtual displacement and virtual strain by the sum of the work is zero. On the other hand, if the force system in the virtual displacement (strain) and virtual and is equal to zero for the work, they must balance equation. Virtual displacement principle formulated the system of force balance, therefore, necessary and sufficient conditions. In general, the virtual displacement principle can not only suitable for linear elastic problems, and can be used in the nonlinear elastic and elastic-plastic nonlinear problem.Virtual mechanical meaning of stress principle: if the displacement is coordinated, the virtual stress and virtual boundary constraint counterforce in which they are the sum of the work is zero. On the other hand, if the virtual force system in which they are and is zero for the work, they must be meet the coordination. Virtual stress in principle, therefore, necessary and sufficient condition for the expression of displacement coordination. Virtual stress principle can be applied to different linear elastic and nonlinear elastic mechanics problem. But it must be pointed out that both principle of virtual displacement and virtual stress principle, rely on their geometric equation and equilibrium equation is based on the theory of small deformation, they cannot be directly applied to mechanical problems based on large deformation theory. 3,,,,, the minimum total potential energy method of minimum total potential energy method, the minimum strain energy method of minimum total potential energy method, the potential energy function in the object on the external load will cause deformation, the deformation force during the work done in the form of elastic energy stored in the object, is the strain energy.The convergence of the finite element method, the convergence of the finite element method refers to when the grid gradually encryption, the finite element solution sequence converges to the exact solution; Or when the cell size is fixed, the more freedom degree each unit, the finite element solutions tend to be more precise solution. Convergence condition of the convergence condition of the finite element finite element convergence condition of the convergence condition of the finite element finite element includes the following four aspects: 1) within the unit, thedisplacement function must be continuous. Polynomial is single-valued continuous function, so choose polynomial as displacement function, to ensure continuity within the unit. 2) within the unit, the displacement function must include often strain. Total can be broken down into each unit of the state of strain does not depend on different locations within the cell strain and strain is decided by the point location of variables. When the size of the units is enough hours, unit of each point in the strain tend to be equal, unit deformation is uniform, so often strain becomes the main part of the strain. To reflect the state of strain unit, the unit must include the displacement functions often strain. 3) within the unit, the displacement function must include the rigid body displacement. Under normal circumstances, the cell for a bit of deformation displacement and displacement of rigid body displacement including two parts. Deformation displacement is associated with the changes in the object shape and volume, thus producing strain; The rigid body displacement changing the object position, don't change the shape and volume of the object, namely the rigid body displacement is not deformation displacement. Spatial displacement of an object includes three translational and three rotational displacement, a total of six rigid body displacements. Due to a unit involved in the other unit, other units do rigid body displacement deformation occurs will drive unit, thus, to simulate real displacement of a unit, assume that the element displacement function must include the rigid body displacement. 4) the displacement function must be coordinated in public boundary of the adjacent cell. For general unit of coordination is refers to the adjacent cell in public node have the same displacement, but also have the same displacement along the edge of the unit, that is to say, to ensure that the unit does not occur from cracking and invade the overlap each other. To do this requires the function on the common boundary can be determined by the public node function value only. For general unit and coordination to ensure the continuity of the displacement of adjacent cell boundaries. However, between the plate and shell of the adjacent cell, also requires a displacement of the first derivative continuous, only in this way, to guarantee the strain energy of the structure is bounded. On the whole, coordination refers to the public on the border between neighboring units satisfy the continuity conditions. The first three, also called completeness conditions, meet the conditions of complete unit is complete unit; Article 4 is coordination requirements, meet the coordination unit coordination unit; Otherwise known as the coordinating units. Completeness requirement is necessary for convergence, all four meet, constitutes a necessary and sufficient condition for convergence. In practical application, to make the selected displacement functions all meet the requirements of completeness and harmony, it is difficult in some cases can relax the requirement for coordination. It should be pointed out that, sometimes the coordination unit than its corresponding coordination unit, its reason lies in the nature of the approximate solution. Assumed displacement function is equivalent to put the unit under constraint conditions, the unit deformation subject to the constraints, this just some alternative structure compared to the real structure. But the approximate structure due to allow cell separation, overlap, become soft, the stiffness of the unit or formed (suchas round degree between continuous plate unit in the unit, and corner is discontinuous, just to pin point) for the coordination unit, the error of these two effects have the possibility of cancellation, so sometimes use the coordination unit will get very good results. In engineering practice, the coordination of yuan must pass to use "small pieces after test". Average units or nodes average processing method of stress stress average units or nodes average processing method of stress average units or nodes average processing method of stress of the unit average or node average treatment method is the simplest method is to take stress results adjacent cell or surrounding nodes, the average value of stress.1. Take an average of 2 adjacent unit stress. Take around nodes, the average value of stressThe basic steps of finite element method to solve the problemThe structural discretization structure discretization structure discretization structure discretization to discretization of the whole structure, will be divided into several units, through the node connected to each other between the units; 2. The stiffness matrix of each unit and each element stiffness matrix and the element stiffness matrix and the stiffness matrix of each unit (3) integrated global stiffness matrix integrated total stiffness matrix integrated overall stiffness matrix integrated total stiffness matrix and write out the general balance equations and write out the general balance equations and write out the general balance equations and write a general equation 4. Introduction of supporting conditions, the displacement of each node 5. Calculate the stress and strain in the unit to get the stress and strain of each cell and the cell of the stress and strain and the stress and strain of each cell.For the finite element method, the basic ideas and steps can be summarized as: (1) to establish integral equation, according to the principle of variational allowance and the weight function or equation principle of orthogonalization, establishment and integral expression of differential equations is equivalent to the initial-boundary value problem, this is the starting point of the finite element method. Unit (2) the area subdivision, according to the solution of the shape of the area and the physical characteristics of practical problems, cut area is divided into a number of mutual connection, overlap of unit. Regional unit is divided into finite element method of the preparation, this part of the workload is bigger, in addition to the cell and node number and determine the relationship between each other, also said the node coordinates, at the same time also need to list the natural boundary and essential boundary node number and the corresponding boundary value.(3) determine the unit basis function, according to the unit and the approximate solution of node number in precision requirement, choose meet certain interpolation condition basis function interpolation function as a unit. Basis function in the finite element method is selected in the unit, due to the geometry of each unit has a rule in the selection of basis function can follow certain rules. (4) the unit will be analysis: to solve the function of each unit with unit basis functions toapproximate the linear combination of expression; Then approximate function generation into the integral equation, and the unit area integral, can be obtained with undetermined coefficient (i.e., cell parameter value) of each node in the algebraic equations, known as the finite element equation. (5) the overall synthesis: after the finite element equation, the area of all elements in the finite element equation according to certain principles of accumulation, the formation of general finite element equations. (6) boundary condition processing: general boundary conditions there are three kinds of form, divided into the essential boundary conditions (dirichlet boundary condition) and natural boundary conditions (Riemann boundary conditions) and mixed boundary conditions (cauchy boundary conditions). Often in the integral expression for natural boundary conditions, can be automatically satisfied. For essential boundary conditions and mixed boundary conditions, should be in a certain method to modify general finite element equations satisfies. Solving finite element equations (7) : based on the general finite element equations of boundary conditions are fixed, are all closed equations of the unknown quantity, and adopt appropriate numerical calculation method, the function value of each node can be obtained.有限元分析有限元法求解区域是由许多小的节点连接单元（域），该模型给出了切分的基本方程（子域名）的近似解，由于单位（域）可以分为不同的形状和大小不同的尺寸，所以它能很好的适应复杂的几何形状、材料特性和边界条件复杂，复杂有限元模型：它是真实系统的理想化的数学抽象。

利用有限元模型对钻机进行动态分析的研究

利用有限元模型对钻机进行动态分析的研究摘要现在的工作的目的是使用分析和实验的结果发展和改进钻机的有限元分析模型，这种有限元分析已经用在监测将钻机的工作特性修改后对钻机动态的结构的影响；对钻机将有两个研究就进行。

第一个研究是：使用工具对钻机进行冲击来观察这种冲击对钻机的影响的实验已经在进行，通过人们公认对模型的证明我门已经知道这种方法的可行性；为了这一个有限元模型分析的机器，一个计算机程序已经被设计出来。

有限元分析获得的结果是将通过实验得到模型的比较与测量和控制的价值联系起来。

有限元分析模型已经被改进，是由于一个已经使用的有限元分析模型程序的改进。

第二个研究是：模式上的测试已经完成，这种测试包括运用各种任意的声音和模式的刺激。

公认的模式的测试方法被用来作为这种有限元分析模型的证据。

利用I-DEAS软件已经对有限元分析模型的作了分析。

利用FEMtools软件已经对有限元分析模型和实验得到的结果的联系进行了分析，利用以上两种软件已经对有限元分析模型进行了间接的改进。

灵敏度基于对参数估量的技术。

通过以上两种研究，对这种分析模型进行结构和动态的修改。

我们对动态设计的结果和结构和动态的修改相当的满意。

目录1.绪论；2.模型的测试和结论；3.钻机的有限元分析元素的表达；4.有限元分析的结果和实验结果的比较；5.有限元分析的发展；6.利用有限元分析对动态设计的动态和结构的修正；7.结论。

参考文献1．绪论动态设计的目的在于获得想要的机器和构件的动态参数，这些动态参数包括震荡频率，想要得到的结构尺寸和震荡响应，而根本的目的是有一个安静和舒适的环境，高的可靠性和更好的产品质量。

常规的动态设计是通过很多的原形的分析和实验来获得自己想要的参数。

这个设计的缺点是：要进行这个实验和分析需要很多的时间和精力，所以根本就没有效率所言。

然而，新型的有限元分析节省了时间节省了有关的花费。

动态设计所用的各种方法是：实验的模型分析（形态测试和实验确认），模型改进和结构上的，形态上的修改。

ANSYS有限元分析外文文献翻译、中英文翻译

附录1：外文翻译CAE的技术种类有很多，其中包括有限元法,边界元法,有限差法等。

每一种方法各有其应用的领域，而其中有限元法应用的领域越来越广，现已应用于结构力学、结构动力学、热力学、流体力学、电路学、电磁学等。

ANSYS软件是融结构、流体、电场、磁场、声场分析于一体的大型通用有限元分析软件。

由世界上最大的有限元分析软件公司之一的美国ANSYS开发，它能与多数CAD软件接口，实现数据的共享和交换，如Pro/Engineer, NASTRAN, Alogor, I－DEAS, AutoCAD等，是现代产品设计中的高级CAE工具之一。

ANSYS有限元软件包是一个多用途的有限元法计算机设计程序，可以用来求解结构、流体、电力、电磁场及碰撞等问题。

因此它可应用于以下工业领域：航空航天、汽车工业、生物医学、桥梁、建筑、电子产品、重型机械、微机电系统、运动器械等。

有限元分析（FEA，Finite Element Analysis）的基本概念是用较简单的问题代替复杂问题后再求解。

它将求解域看成是由许多称为有限元的小的互连子域组成，对每一单元假定一个合适的(较简单的）近似解，然后推导求解这个域总的满足条件(如结构的平衡条件），从而得到问题的解。

这个解不是准确解，而是近似解，因为实际问题被较简单的问题所代替。

由于大多数实际问题难以得到准确解，而有限元不仅计算精度高，而且能适应各种复杂形状，因而成为行之有效的工程分析手段。

有限元是那些集合在一起能够表示实际连续域的离散单元。

有限元的概念早在几个世纪前就已产生并得到了应用，例如用多边形（有限个直线单元）逼近圆来求得圆的周长，但作为一种方法而被提出，则是最近的事。

有限元法最初被称为矩阵近似方法，应用于航空器的结构强度计算，并由于其方便性、实用性和有效性而引起从事力学研究的科学家的浓厚兴趣。

经过短短数十年的努力，随着计算机技术的快速发展和普及，有限元方法迅速从结构工程强度分析计算扩展到几乎所有的科学技术领域，成为一种丰富多彩、应用广泛并且实用高效的数值分析方法。

有限元分析报告报告材料英文文献

有限元分析报告报告材料英文文献The Basics of FEA Procedure有限元分析程序的基本知识2.1 IntroductionThis chapter discusses the spring element, especially for the purpose of introducing various concepts involved in use of the FEA technique.本章讨论了弹簧元件，特别是用于引入使用的有限元分析技术的各种概念的目的A spring element is not very useful in the analysis of real engineering structures; however, it represents a structure in an ideal form for an FEA analysis. Spring element doesn’t require discretization (division into smaller elements) and follows the basic equation F = ku.在分析实际工程结构时弹簧元件不是很有用的;然而,它代表了一个有限元分析结构在一个理想的形式分析。

弹簧元件不需要离散化(分裂成更小的元素)只遵循的基本方程F = ku We will use it solely for the purpose of developing an understanding of FEA concepts and procedure.我们将使用它的目的仅仅是为了对开发有限元分析的概念和过程的理解。

2.2 Overview概述Finite Element Analysis (FEA), also known as finite element method (FEM) is based on the concept that a structure can be simulated by the mechanicalbehavior of a spring in which the applied force is proportional to the displacement of the spring and the relationship F = ku is satisfied.有限元分析(FEA),也称为有限元法(FEM)，是基于一个结构可以由一个弹簧的力学行为模拟的应用力弹簧的位移成正比,F = ku切合的关系。

塔式起重机有限元分析外文翻译

FEM Optimization for Robot StructureWang Shijun, Zhao Jinjuan*Department of Mechanical Engineering, Xi'an University of TechnologyShaanxi Province, People's Republic of ChinaInstitute of Printing and Packing Engineering, Xi'an University of TechnologyAbstractIn optimal design for robot structures, design models need to he modified and computed repeatedly. Because modifying usually can not automatically be run, it consumes a lot of time. This paper gives a method that uses APDL language of ANSYS 5.5 software to generate an optimal control program, which mike optimal procedure run automatically and optimal efficiency be improved.1）IntroductionIndustrial robot is a kind of machine, which is controlled by computers. Because efficiency and maneuverability are higher than traditional machines, industrial robot is used extensively in industry. For the sake of efficiency and maneuverability, reducing mass and increasing stiffness is more important than traditional machines, in structure design of industrial robot.A lot of methods are used in optimization design of structure. Finite element method is a much effective method. In general, modeling and modifying are manual, which is feasible when model is simple. When model is complicated, optimization time is longer. In the longer optimization time, calculation time is usually very little, a majority of time is used for modeling and modifying. It is key of improving efficiency of structure optimization how to reduce modeling and modifying time.APDL language is an interactive development tool, which is based on ANSYS and is offered to program users. APDL language has typical function of some large computer languages. For example, parameter definition similar to constant and variable definition, branch and loop control, and macro call similar to function and subroutine call, etc. Besides these, it possesses powerful capability of mathematical calculation. The capability of mathematical calculation includes arithmetic calculation, comparison, rounding, and trigonometric function, exponentialfunction and hyperbola function of standard FORTRAN language, etc. By means of APDL language, the data can be read and then calculated, which is in database of ANSYS program, and running process of ANSYS program can be controlled.Fig. 1 shows the main framework of a parallel robot with three bars. When the length of three bars are changed, conjunct end of three bars can follow a given track, where robot hand is installed. Core of top beam is triangle, owing to three bars used in the design, which is showed in Fig.2. Use of three bars makes top beam nonsymmetrical along the plane that is defined by two columns. According to a qualitative analysis from Fig.1, Stiffness values along z-axis are different at three joint locations on the top beam and stiffness at the location between bar 1 and top beam is lowest, which is confirmed by computing results of finite element, too. According to design goal, stiffness difference at three joint locations must he within a given tolerance. In consistent of stiffness will have influence on the motion accuracy of the manipulator under high load, so it is necessary to find the accurate location of top beam along x-axis.To the questions presented above, the general solution is to change the location of the top beam many times, compare the results and eventually find a proper position, The model will be modified according to the last calculating result each time. It is difficult to avoid mistakes if the iterative process is controlled manually and the iterative time is too long. The outer wall and inner rib shapes of the top beam will be changed after the model is modified. To find the appropriate location of top beam, the model needs to be modified repetitiously.Fig. 1 Solution of Original DesignThis paper gives an optimization solution to the position optimization question of the top beam by APDL language of ANSYS program. After the analysis model first founded, the optimization control program can be formed by means of modeling instruction in the log file. The later iterative optimization process can be finished by the optimization control program and do not need manual control. The time spent in modifying the model can be decreased to the ignorable extent. The efficiency of the optimization process is greatly improved.2）Construction of model for analysisThe structure shown in Fig. 1 consists of three parts: two columns, one beam and threedriving bars. The columns and beam are joined by the bolts on the first horizontal rib located on top of the columns as shown in Fig.1. Because the driving bars are substituted by equivalent forces on the joint positions, their structure is ignored in the model.The core of the top beam is three joints and a hole with special purpose, which can not be changed. The other parts of the beam may be changed if needed. For the convenience of modeling, the core of the beam is formed into one component. In the process of optimization, only the core position of beam along x axis is changed, that is to say, shape of beam core is not changed. It should be noticed that, in the rest of beam, only shape is changed but the topology is not changed and which can automatically be performed by the control program.Fig.1, six bolts join the beam and two columns. The joint surface can not bear the pull stress in the non-bolt joint positions, in which it is better to set contact elements. When the model includes contact elements, nonlinear iterative calculation will be needed in the process of solution and the computing time will quickly increase. The trial computing result not including contact element shows that the outside of beam bears pulling stress and the inner of beam bears the press stress. Considering the primary analysis object is the joint position stiffness between the top beam and the three driving bars, contact elements may not used, hut constructs the geometry model of joint surface as Fig.2 showing. The upper surface and the undersurface share one key point in bolt-joint positions and the upper surface and the under surface separately possess own key points in no bolt positions. When meshed, one node will be created at shared key point, where columns and beam are joined, and two nodes will be created at non shared key point, where column and beam are separated. On right surface of left column and left surface of right column, according to trial computing result, the structure bears press stress. Therefore, the columns and beam will share all key points, not but at bolts. This can not only omit contact element but also show the characteristic of bolt joining. The joining between the bottoms of the columns and the base are treated as full constraint. Because the main aim of analysis is the stiffness of the top beam, it can be assumed that the joint positions hear the same as load between beam and the three driving bars. The structure is the thin wall cast and simulated by shell element . The thickness of the outside wall of the structure and the rib are not equal, so twogroups of real constant should he set. For the convenience of modeling, the two columns are also set into another component. The components can create an assembly. In this way, the joint positions between the beam core and columns could he easily selected, in the modifying the model and modifying process can automatically be performed. Analysis model is showed Fig.1. Because model and load are symmetric, computing model is only half. So the total of elements is decreased to 8927 and the total of nodes is decreased to 4341. All elements are triangle.3.）Optimization solutionThe optimization process is essentially a computing and modifying process. The original design is used as initial condition of the iterative process. The ending condition of the process is that stiffness differences of the joint locations between three driving bars and top beam are less than given tolerance or iterative times exceed expected value. Considering the speciality of the question, it is foreseen that the location is existent where stiffness values are equal. If iterative is not convergent, the cause cannot be otherwise than inappropriate displacement increment or deficient iterative times. In order to make the iterative process convergent quickly and efficiently, this paper uses the bisection searching method changing step length to modify the top beam displacement. This method is a little complex but the requirement on the initial condition is relatively mild.The flow chart of optimization as follows:1. Read the beam model data in initial position from backup file;2. Modify the position of beam;3. Solve;4. Read the deform of nodes where beam and three bars are joined;5. Check whether the convergent conditions are satisfied, if not, then continue to modify the beam displacement and return to 3, otherwise, exit the iteration procedure.6. Save the results and then exit.The program's primary control codes and their function commentaries are given in it, of which the detailed modeling instructions are omitted. For the convenience of comparing with the control flow, the necessary notes are added.the flag of the batch file in ANSYSBATCH RESUME, robbak.db, 0read original data from the backupfile robbak,.db/PREP7 enter preprocessordelete the joint part between beam core and columnsmove the core of the beam by one :step lengthapply load and constraint on the geometry meshing thejoint position between beam core and columns FINISH exit the preprocessorISOLU enter solverSOLVE solveFINISH exit the solverPOST1 enter the postprocessor*GET ,front,NODE,2013,U,Z read the deformation of first joint node on beam*GET,back,NODE, 1441 ,U,Z read the deformation of second joint node on beam intoparameter hacklastdif-1 the absolute of initial difference between front and hacklast timeflag=- 1 the feasibility flag of the optimizationstep=0.05 the initial displacement from initial position to the currentposition*D0,1,1,10,1 the iteration procedure begin, the cycle variable is I andits value range is 1-10 and step length is 1dif=abs(front-back) the absolute of the difference between front and hack inthe current result*IF,dif,LE,l .OE-6,THEN check whether the absolute difference dif satisfies therequest or noflag=l yes, set flag equal to 1*EXIT exit the iterative calculation*ELSEIF,dif,GE,lastdif,THEN check whether the dif value becomes great or not flag=2yes, set flag 2 modify step length by bisection methodperform the next iterative calculation, use the lastposition as the current position and modified last steplength as the current step lengthELSE if the absolute of difference value is not less thanexpected value and become small gradually, continue tomove top beam read the initial condition from back upfile enter the preprocessorMEN, ,P51X, , , step,, , ,1 move the core of the beam by one step length modify thejoint positions between beam core and column applyload and constraint meshingFINISH exit preprocessorISOLU enter solverSOLVE solveFINISH exit the solver/POST1 exit the postprocessor*GET,front,NODE,201 3,U,Z read the deformation of first joint node to parameter front *GET,back,NODE, 144 1,U,Z read the deformation of second joint node to parameter back lastdif-dif update the value of last dif*ENDIF the end of the if-else*ENDDO the end of the DO cycleMost of the control program above is copied from log file, which is long. The total of lines is up to about 1000 lines. Many codes such as modeling and post-process codes are used repeatedly. To make the program construct clear, these instructions can he made into macros, which are called by main program. This can efficiently reduce the length of the main program. In addition, modeling instructions from log file includes lots of special instructions that are only used under graphic mode but useless under hatch mode. Deleting and modifying these instructions when under batch mode in ANSYS can reduce the length of the file, too.In the program above, the deformation at given position is read from node deformation. In meshing, in order to avoid generating had elements, triangle mesh is used. In optimization, the shape of joint position between columns and beam continually is changed. This makes total of elements different after meshing each time and then element numbering different, too. Data read from database according to node numbering might not he data to want. Therefore, beam core first needs to he meshed, then saved. When read next time, its numbering is the same as last time.Evaluating whether the final result is a feasible result or not needs to check the flag value. Ifonly the flag value is I, the result is feasible, otherwise the most proper position is not found. The total displacement of top beam is saved in parameter step. If the result is feasible, the step value is the distance from initial position to the most proper position. The sum of iterative is saved in parameter 1. According to the final value of I, feasibility of analysis result and correctness of initial condition can he evaluated.4）Optimization resultsThe sum of iterative in optimization is seven, and it takes about 2 hour and 37 minutes to find optimal position. Fig.3 shows the deformation contour of the half-construct. In Fig.3, the deformations in three joints between beam and the three driving bars is the same as level, and the corresponding deformation range is between -0.133E-04 and -0.1 15E-O4m, the requirement of the same stiffness is reached. At this time, the position of beam core along x-axis as shown in Fig. 1 has moved -0.71E-01m compared with the original designed positionBecause the speed of computer reading instruction is much faster than modifying model manually, the time modifying model can be ignored. The time necessary foroptimization mostly depends on the time of solution. Compared with the optimization procedure manually modifying model, the efficiency is improved and mistake operating in modeling is avoided.5）ConclusionThe analyzing result reveals that the optimization method given in this paper is effective and reaches the expected goal. The first advantage of this method is that manual mistakes do not easily occur in optimization procedure. Secondly, it is pretty universal and the control codes given in this paper may he transplanted to use in similar structure optimization design without large modification. The disadvantage is that the topology structure of the optimization object can not be changed. The more the workload of modifying the model, the more the advantages of this method are shown. In addition, the topology optimization function provided in ANSYS is used to solve the optimization problem that needs to change the topology structure.The better optimization results can he achieved if the method in this paper combined with中文译文：机器人机构优化设计有限元分析王世军赵金娟西安大学机电工程系中国陕西西安大学出版社摘要机器人结构最优化设计，设计模型需要反复的修正和计算。

外文翻译对于有限元分析的介绍

本科生毕业设计 (论文)
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原文标题INTRODUCTION TO THE FINITE ELEMENT
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译文标题对于有限元分析的介绍
作者所在系别机械工程系
作者所在专业机械设计制造及其自动化
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注：1. 指导教师对译文进行评阅时应注意以下几个方面：①翻译的外文文献与毕业设计（论文）的主题是否高度相关，并作为外文参考文献列入毕业设计（论文）的参考文献；②翻译的外文文献字数是否达到规定数量（3 000字以上）；③译文语言是否准确、通顺、具有参考价值。

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外文翻译金属切削加工有限元模拟技术发展现状分析

中北大学信息商务学院外文翻译金属切削加工有限元模拟技术发展现状分析学生姓名：许丽莎学号：12020144X01系别：机械工程系专业：机械设计制造及其自动化指导教师：武文革职称：教授2016年6月2日Finite element analysis system development present situation and forecastAlong with modern science and technology development,the people unceasingly are making the faster transportation vehicle,the large-scale building,the greater span bridge,the high efficiency power set and the preciser mechanical device.All these request engineer to be able precisely to forecast in the design stage the product and the project technical performance, needs to be static,technical parameter and so on dynamic strength to the structure as well as temperature field,flow field,electromagnetic field and transfusion carries on the analysis computation.For example analysis computation high-rise construction and great span bridge when earthquake receives the influence,has a look whether can have the destructive accident; The analysis calculates the nuclear reactor the temperature field,the determination heat transfer and the cooling system are whether reasonable;Analyzes in the new leaf blade the hydrodynamics parameter,enhances its operating efficiency.The sell may sum up as the solution physics question control partial differential equations often is not impossible.In recent years the finite element analysis which develops in the computer technology and under the numerical analysis method support(FEA,Finite Element Analysis)the side principle for solves these complex project analysis estimation problems to provide the effective way. Our country in"95"Plan period vigorously promotes the CAD technology,mechanical profession large and middle scalene terries CAD popular rate from"85"End20%enhances that present70%.With enterprise application of CAD,engineering and technical personnel has gradually get rid drawing board,and will join the main energy how to optimize the design, engineering and improving the quality of products,computer-aided engineering analysis (puter Aided Engineering)method and software will be the key technical elements.ln engineering practice,finite element analysis software and CAD system integration design standards should be a qualitative leap,mainly in the following aspects:The increase design function,reduces the design cost;Reduces design and the analysis cycle period;Increase product and project reliability;Uses the optimized design,reduces the material the consumption or the cost;Discovers the latent question in advance before the product facture or the project construction; Simulates each kind of experimental plan,reduces the experimental time and the funds; Carries on the machine accident to analyze,search accident cause factor.In vigorously promotes the CAD technology today,from the bicycle to the aerospace craft,all designs manufacture all will not be able to leave the finite element analysis computation,FEA obtains the more and more widespread value in the engineering design and the analysis.The next chart is the American San Francisco bay bridge earthquake responds the computation the finite element analysis model.The development direction and on significant progress international early20th century in the end of the50's,at the beginning of the60's has the formidable function on the investment massive manpower and the physical resource development the finite element analysis procedure.What is most famous was (NASA)entrusts US by American country Space Agency in1965to calculate the NASTRAN finite element analysis system which the scientific company and the Bell aerospace system company developed.This system development until now had several dozens editions,is in the present world the scale is biggest,the function strongest finite element analysis system.From at that time to the present,the world each place development facility and the university also developed one batch of scales smaller but to use nimble,the price is lower special-purpose or general finite element analysis software,mainly had German ASKA,England's PAFEC,France's company's the and so on SYSTUS,US'S ABQUS,ADINA,ANSYS,BERSAFE,BOSOR,COSMOS, ELAS,MARC and STARDYNE product.Now on the international FEA method and the software development presents below some tendency characteristics:1.develops from the pure structure mechanics computation to solves many physical fieldsquestion finite element analysis method most early is comes from the structure matrix analysis development,gradually promotes to the board,the shell and the entity and so on the continual body solid mechanics analysis,the practice proved this is one extremelyeffective numerical analysis method.Moreover the or etically also already proved,so long as uses in to be separated solution object the unit enough to be small,the obtained solution may enough approach to the precise value.Therefore the recent years finite element method has developed question the and so on hydromechanics,temperature field,electricity conduction,magnetic field,transfusion and sound field solution computation,recently developed solves several inter disciplinary studies. the questions.For example when the air current flows a very high iron tower to have the distortion,but the tower distortion in turn affects to the air current flows.This needs to use the solid mechanics and the hydrodynamics finite element analysis finally overlapping iteration solves,namely so-called"Flows solid coupling"Question.2Progresses from the solution linear project question to the analysis non-linear problem along with the science and technology development,the linear theory already by far could not satisfy the design there quest.For example in construction profession high-rise construction and great span hanging bridge appearance,request consideration geometry non-linear problem and so on structure big displacement and big strain;Astronautics and power engineering high temperature part existence thermal deformation and thermal load,also must consider the material the non-linear problem;Such as the plastic,the rubber and the compound material and so on each kind of new material appearance,only depends on the question which the linear computation theory is insufficient to solve meets,only has uses the non-linear finite element algorithm to be able to solve.It is well known,the non-linear value computation is very complex,it involves to the very many special mathematics question and the operation skill,thanks the general engineering technical personnel to grasp very much.Has spent massive specialty and so on manpower and investment development such as MARC,ABQUS and ADINA for this recent years overseas some companies to solution non-linear problem finite element analysis software,and widely applies to the project practice.These software common characteristics are have the highly effective non-linear solution as well as rich and the practical non-linear material.Definitely.3The enhancement visible pretag e modelling and the post positioned data processing function early time finite element analysis software research key lies in infers new highefficiency solution method and the high accuracy unit.Along with the numerical analysis method gradually consummation,the computer operating speed rapid development,the entire computing system uses in to solve the operation in particular the time more and more few,but the data preparation and the operation result performance question day by day is actually prominent.On the present project workstation,solves to contain100,000equations the finite lement models only to need to use several dozens minutes.But if establishes this model with the manual way,then the rehandling massive computed result must use several week-long time.May not exaggerate said,engineer calculates a project question when the analysis has 80%above the energy all to spend in the data preparation and the result analysis. Therefore the present nearly all shangye finite element software all has the function very strong pretage modeling and the post positioned data processing module.Is emphasizing" Visible"Today,very many procedures have all established to user extremely friendly GUI (Graphics User Interface),enables the user direct-viewing fast to carry on the grid automatic division by the visible graphic mode,the production finite element analysis needs the data, and the massive computed result will reorganize the distortion chart,the equivalentd is tribution cloud chart according to the request,will be advantageous for the extreme value search and needs the data to tabulate the output.4With the CAD software seamless integration now the finite element analysis system another characteristic is and the general CAD software integrated use namely,after uses CAD software to complete the part and the components modeling design,automatically produces the finite element grid and carries on the computation,if analyzes the result does not conform to the design requirement then recarries on the modeling and the computation,until satisfaction,thus enormously raised the design level and the efficiency.The complex project analysis question today,which engineer may quickly solves in integrated CAD and in the FEA software environment in before is unable to deal with. Therefore now all shangye finite element system business all has developed and famous CAD software(for example Pro/ENGINEER,Unigraphics,SolidEdge,SolidWorks,IDEAS, Bentley and AutoCAD and so on)connection.5Basically in Wintel platform development early time finite element analysis software all is in the large and middle scale computers(mainly is Mainframe)on the development and the movement,after wards also developed take the project workstation(EWS,Engineering WorkStation)as the platform,their common characteristic all uses the UNIX operating system..The PC machine appearance caused the computer the application to have he fundamental change,engineer had longed for completed the complex project analysis on the desk the dream to become the reality.But early PC machine uses16CPU and the DOS operating system,in the memory public block data is restricted,at that time there fore calculated the model the scale not to be able to surpass10,000steps equations.Microsoft the Windows operating system and32Intel Pentium processor promoting for used in the finite element analysis PC machine to provide essential software and the hardware supports the platform.Therefore on the current international famous finite element procedure research and the development organization all in abundance move theirs software the value to the Wintel platform in.Next cava logged version environment and the SGI workstation simultaneously calculates the solution time with ADINA the V7.3in PC machine Windows on the NT which 4projects examples needed.May see the newest upscale PC machine solution ability already and center low-grade EWS is equally matched.In order to will develop on the large and middle scale computers and EWS the finite element procedure will move the value to PE machine on,frequently will need to use Hummingbird Corporation simulation software Exceed.Does this the result quite is troublesome,moreover cannot fully use the PC machine software and hardware resources. Therefore recently some companies,for example IDEAS,ADINA and R&D starts in the Windows platform to develop the finite element procedure,is called as"Native Windows" The edition,meanwhile has the finite element routine package which in on Linux operating system environment develops in PC machine.The domestic development situation and the prospect in1979US'S SAP5linear structure was static,the mechanical analysis procedure transplants successfully to the domestic introduction,raised the application general finite element procedure to analyze the computation project question the high tide.This high tide continuously continued to1981theADINA non-linear structure analysis procedure introduction,many continuously was unable the project difficult problem which solved all to be easily solved for a while.Everybody also starts to realize indeed is engineer carries on then is computation to the finite element analysis procedure using the computer the important tool。

有限元大论文

浅议钻机变速箱齿轮在有限元中的分析摘要：本文通过直接在ANSYS软件中直接建立模型，并在ANSYS中用有限元进行应力分析，计算出齿轮的最大应力和最大应变。

结果表明，通过ANSYS软件分析的结果与真实情况很接近。

关键词：钻机；变速箱；直齿圆柱齿轮；应力分析；ANSYS；失效ANSYS analysis on Change Speed Gear Box of Drilling machine Abstract：In the article ，the model of the cylinder gear is established by ANSYS directly. Maximum stress and strain of the gear are calculated by stress analysis with finite element．It shows that the Result from ANSYS software analysis is quite close to the reality．Key words：drifting fig；change speed box；straight—cylinder gear；stress analysis；ANSYS；lose efficacy变速箱齿轮是钻探设备工作的核心部件之一，齿轮失效会很大程度影响工作效率。

因为钻机的工况有时非常恶劣，为了保证重要零件有较高的安全系数,钻机变速箱的设计除了考虑结构优化、加工经济，同时还需考虑使用工况。

齿轮失效的形式有很多种，常见的有轮齿的折断、工作齿面磨损、点蚀、胶合以及塑性变形等。

轮齿在传动过程中承受的是分布线载荷，如果用静力等效的集中载荷代替，计算出的结果与真实情况是有区别的。

经典的齿轮强度校核理论有着一定的局限性，用有限元法则没有限制。

目前，工程技术领域内的数值模拟方法，主要是有限元法。

本文采用ANSYS有限元分析软件，对直齿圆柱齿轮加载求解，计算出轮齿传动过程中所受的最大应力、应变等。

外文翻译---利用有限元法预测夹具系统的工件变形（有word版）.pdf

Prediction of workpiece deformation in aﬁxture systemusing theﬁnite element methodShane P.Siebenaler,Shreyes N.Melkote*The George W.Woodruff School of Mechanical Engineering,Georgia Institute of Technology,Atlanta,GA30332-0405,USAReceived25August2004;accepted7April2005Available online23May2005AbstractKnowledge of workpiece deformations induced by loading in aﬁxture–workpiece system is important to ensure quality part production. Suitable methods for accurately predicting such deformations are essential to the design and operation ofﬁxtures.In this regard,ﬁnite element modeling has been widely applied by researchers and practitioners.However,these studies generally neglect the role of compliance of theﬁxture body on workpiece deformation.Also lacking is knowledge of the effects of differentﬁnite element model parameters on workpiece deformation.This study usesﬁnite element analysis(FEA)to model aﬁxture–workpiece system and to explore the inﬂuence of compliance of theﬁxture body on workpiece deformation.In addition,the effects of certainﬁnite element model parameters on the prediction accuracy are also examined.Experimental veriﬁcation of the workpiece deformations and locator reaction forces predicted by the FEA model shows agreement within5%of the experimental data.For theﬁxture–workpiece system analyzed in this study,it was found that98%of all system compliance is captured by modeling just the workpiece andﬁxture contact tips.The remainder of deformation occurred in the other ﬁxture components.The accuracy and computational time tradeoffs are given for variousﬁxture models.q2005Elsevier Ltd.All rights reserved.Keywords:Fixture-work piece system;Finite element analysis;Deformation1.IntroductionMethods for analyzingﬁxtures are essential to the practice and economics of machining.In particular,the ability to model and accurately predict workpiece deformation induced by ﬁxturing loads and/or predict the unknownﬁxture–workpiece contact forces are crucial for designing functionalﬁxtures.The most common modeling and analysis approaches used for ﬁxture–workpiece systems include the rigid body approach,the contact mechanics based approach and theﬁnite element modeling approach.Of these approaches,the rigid body modeling approach[1–3]is by deﬁnition incapable of predicting workpiece deformations and is therefore unsuitable for analysis of the impact ofﬁxturing on part quality.The contact mechanics approach,although attractive from a standpoint of computational effort,is limited to parts that can be approximated as elastic half-spaces.Models derived from this approach are capable of accurately predicting unknown locator reaction forces and localized contact deformations[4–6].However,they are not applicable for thin,compliant parts. Finite element models on the other hand are very powerful and are capable of accounting for all compliances and non-linearities present in the system.Although use ofﬁnite element models has been widely reported in the literature and employed in practice,a clear understanding of the role of the different ﬁxture compliances on the prediction accuracy of workpiece deformation is lacking.Also knowledge of the effects of differentﬁnite element model parameters on workpiece deformation is lacking.A common assumption in application of Finite Element Analysis(FEA)to analyze aﬁxture–workpiece system is that theﬁxture is completely rigid since it is much stiffer than the workpiece in many applications.In most such cases,the workpiece is modeled and nodes at the location ofﬁxture contact are completely restrained.This formulation is com-monly referred to as a single-point contact[7–12].Omitting ﬁxture elements does not allow for the model to account for compliance in theﬁxture and neglects frictional contact effects between theﬁxture and workpiece.Other researchers[13–16] have utilized linear springs to approximate the stiffness oftheInternational Journal of Machine Tools&Manufacture46(2006)51–58/locate/ijmactool0890-6955/$-see front matter q2005Elsevier Ltd.All rights reserved.doi:10.1016/j.ijmachtools.2005.04.007*Corresponding author.Tel.:C14048948499;fax:C14048949342.E-mail address:*************************.edu(S.N.Melkote).ﬁxture components.However,such an approach requires the stiffness to be measured or approximated,adding time and introducing potential error into the analysis.Recent work [17–19]has explored the use of surface-to-surface contact elements.Such an approach allows frictional effects to be modeled.This methodology was used for the work reported in this paper.Liao et al.[17]used FEA with contact elements to model a multiple-contact ﬁxture system.They,however,did not investigate the effects of friction and meshing parameters on the results.Satyanarayana’s [18,19]work was limited to a single ﬁxture–workpiece contact.More importantly,these studies did not analyze the contribution of ﬁxture body compliance to the overall deformation.This paper investigates the effects of various ﬁnite element modeling parameters,such as friction and mesh density,on workpiece deformation.In addition to modeling the workpiece and ﬁxture tips,as is common,the effect of compliance of other ﬁxture components such as support blocks,base plate,etc.on workpiece deformation is also examined.The FEA predictions of workpiece deformation and locator reactions are experimentally veriﬁed.2.Fixture–workpiece systemThe ﬁxture–workpiece system used in this study consisted of a hollow block of rectangular section anduniform wall thickness restrained in a 3-2-1ﬁxture layout as shown in Fig.1.The aluminum 6061-T6(E Z 70GPa,n Z 0.334)workpiece measured 153mm !127mm !76mm and had a ﬁxed wall thickness (t in Fig.1)ranging from 6to 10mm.Two clamps were used to press the workpiece against six locators:three on the primary plane,two on the secondary plane,and one on the tertiary plane.Spherical and planar hardened AISI 1144steel (E Z 206GPa,n Z 0.296)ﬁxture tips with black oxide ﬁnish were used to locate and clamp the workpiece.The global coordinates of each tip are given in Table 1.3.Model developmentFinite element models were constructed using ANSYS w Version 5.7.Solid models were assembled of the prismatic block and ﬁxture tips.All components in the system were modeled as isotropic elastic bodies.The ﬁxture tips,shown in Fig.2,were modeled as cylinders with either planar (clamp and locator circular contact areas 60and 127mm 2,respectively)or spherical (35mm radius of curvature)end caps.The axial lengths of the planar and spherical tips were 6.4and 10.2mm,respectively.The 10-node tetrahedral element Solid92was used to mesh all solid bodies.Contact between the workpiece and ﬁxture was simu-lated using the quadratic surface-to-surface contact elements Targe170and Conta174.A constant static coefﬁcient of friction was used to establish contact proper-ties at the interfaces.To simulate the locators beingrigidlyZyout of 3-2-1ﬁxture.Table 1Coordinates of locator tipsPlanar Spherical X (mm)Y (mm)Z (mm)X (mm)Y (mm)Z (mm)L130.80.041.927.00.038.1L2132.40.041.9128.60.038.1L30.080.041.90.076.238.1L410.524.80.0 6.721.00.0L510.5112.00.0 6.7108.20.0L6154.066.60.0150.262.70.0C179.1127.041.375.3127.037.5C2153.067.341.3153.063.537.5S.P.Siebenaler,S.N.Melkote /International Journal of Machine Tools &Manufacture 46(2006)51–5852ﬁxed in place,the surface of each locator tip opposite to the contact was restrained in all three translational degrees of freedom.A uniformly distributed pressure was applied over the surface of both clamps in opposite contact to simulate the desired clamping force.The deformation of the workpiece,analyzed in the subsequent sections,was found at two points on the workpiece.The positive directions of these two points,d C1and d C2,are shown in Fig.3.The selection of points was based upon locations on the workpiece that underwent the most deformation due to clamping.3.1.Sensitivity to friction coefﬁcientLaboratory tests conducted by Satyanarayana [18]on the same ﬁxture–workpiece system found an average static coefﬁcient of friction (m )of 0.18between the workpiece and ﬁxture tips.The average was in a range of experimental values from 0.15to 0.25.To test the effect of friction of workpiece deformation prediction,FEA models were constructed for workpiece wall thicknesses of 6–10mm restrained in the ﬁxture previously described.A spectrum of m from 0.15to 0.30was tested in combination with the various wall thicknesses.A summary of the deformation results is given in Table 2.An average difference of 3.1%in deformation prediction was found for a change in m of 0.05.These results show that the effect of small variations in the friction coefﬁcient on the workpiece deformation is quite small.3.2.Treatment of primary plane locatorsA series of models were constructed to determine the inﬂuence of the primary plane locators.For a properly designed 3-2-1layout in which workpiece rotation is prevented,the only normal load taken by the three primary plane locators is the weight of the workpiece.The frictional force produced by such a small load is often dwarfed by the much larger clamping loads.An analysis was performed to determine if the frictional effects at these locators must be accounted for in a modeling approach.Two sets of boundary conditions were applied to blocks with wall thicknesses of 7,8,and 9mm.The ﬁrst set,Case A,included all three primary plane locators subjected to the previously described surface-to-surface contact bound-ary conditions.A value of 0.18was speciﬁed for m .The second conﬁguration,Case B,removed all three of the primary plane locators and simply restrained the bottom surface of the workpiece from translating in the z -direction.A summary of the results is given in Table 3.The FEA showed that the predicted deformations differed between the two boundary condition sets by an average of only 1.31%.This small impact of the bottom locators allows the FEA models to be constructed without the primary plane locators,thus saving considerable computational time.This (Case B)boundary condition set used only 77and 69%of the complete model computational time for the planar and spherical tips,respectively.The omission of the three primary plane locators coupled with restraining the bottom surface of the workpiece was the conﬁguration used for subsequent models.It should be pointed out that this approximation may not be valid when machining loads are also taken intoaccount.Fig.2.Fixture tip geometry.Table 2Effect of variation in friction coefﬁcient w (mm)m d C1(m m)d C2(m m)100.1515.018.00.2015.016.50.2515.015.60.3015.114.790.1520.022.60.2020.021.10.2519.918.90.3020.118.980.1528.030.10.2027.828.60.2527.827.20.3028.225.770.1541.042.20.2040.640.40.2540.738.50.3041.336.360.1564.965.90.2064.463.30.2564.960.2Fig.3.Workpiece deformation points.S.P.Siebenaler,S.N.Melkote /International Journal of Machine Tools &Manufacture 46(2006)51–58534.Effect of mesh densityWhile some published literature uses FEA to analyze workpiece deformation,a rigorous study of the inﬂuence of mesh density on the modeling of ﬁxture–workpiece compliance is lacking.A key factor in determining an appropriate FEA model for this investigation is to select the ideal mesh density.A coarse mesh might yield inaccurate results.However,too ﬁne a mesh might be unnecessary as well as computationally expensive.For this study,the SMRT smart-meshing function of ANSYS w was utilized to construct the solid mesh.Discrete values ranging from 1(most dense mesh)to 10(least dense mesh)were assigned to the various solid parts.A wide spectrum of combinations of ﬁxture and workpiece mesh sizes was used to determine the optimal mesh size.To test the accuracy of the results,the deformation of the workpiece,d C1and d C2,at the location of the two clamps was computed.Experimental results were used as a benchmark for assessing the validity of the simulated results.A test ﬁxture with dimensions identical to the models was constructed.The workpiece for this study had a uniform wall thickness of 7mm.The ﬁxture elements were fastened to a 15mm thick steel base plate.The threaded ﬁxture tips on the primary plane were screwed directly into the base plate.The other locators were screwed into steel support blocks that were in turn each fastened to the base plate via four bolts and two press-ﬁt dowel pins.A picture of the ﬁxture is given in Fig.4.The two clamps,which were similarly fastened to the base plate via steel support blocks,were actuated by a hydraulic hand pump.The order of clamp actuation can inﬂuence workpiece deﬂection as shown by otherresearchers [20,21]and in previous work by the authors [22].However,in the current study,the two clamps were actuated simultaneously by a single hydraulic pump.The difference in actuation times for the two clamps was deemed to be negligible.The deformation at each point was measured using an eddy current proximity probe.The change in magnetic ﬂux of a target patch detected by the sensor was converted to a displacement value by the data acquisition system.Average deformation results over ﬁve trials for each tip and load pair are given in Table 4.The standard deviation for the measurements was 0.43m m.Figs.5and 6show the percentage error between the experimentally measured values and the FEA results for the planar and spherical tip cases,respectively.Plots of the 250N load case at Clamp 1for both spherical and planar tips are given for each wall thickness tested.A similar trend was found for the deformation at Clamp 2as well as for a load of 350N.As depicted in the plots,the workpiece mesh density has the dominant effect on model accuracy.A coarse mesh density can produce results with as much as 20%error.However,as can be observed in Fig.6,the inﬂuence of ﬁxture tip mesh density on the accuracy of the results is much less.The workpiece and ﬁxture SMRT density levels for the planar case,which provided the most accurate results,were ﬁve and two,respectively.No ﬁnite element meshes denser than this combination altered the predicted deformations.For the spherical tip case,a SMRT mesh density level of six for the workpiece and two for the ﬁxture components wasTable 3Effect of primary plane locators w (mm)md C1(m m)d C2(m m)AB %Diff.A B %Diff.100.1515.014.6 2.7618.017.8 1.020.2015.014.6 2.9216.516.40.740.2515.014.5 3.0615.615.50.540.3015.114.6 3.2114.714.60.1690.1520.019.4 2.8922.622.50.810.2020.019.5 2.6321.120.9 1.160.2519.919.4 2.5820.119.9 1.120.3020.119.6 2.6318.918.80.8180.1528.027.4 2.2330.130.00.060.2027.827.3 1.8328.628.50.490.2527.827.2 2.0027.227.20.110.3028.227.6 1.9825.725.70.0770.1541.040.3 1.5842.242.20.110.2040.639.9 1.8040.440.60.610.2540.740.0 1.5238.538.80.690.3041.340.6 1.5736.336.70.9960.1564.964.30.9265.965.50.640.2064.463.7 1.1563.363.20.120.2564.964.30.9160.260.10.23Table 4Experimental datad C1(m m)d C2(m m)250N Planar 26.520.5Spherical 29.428.3350NPlanar 36.228.9Spherical41.338.5Fig.4.Experimental 3-2-1ﬁxture.S.P.Siebenaler,S.N.Melkote /International Journal of Machine Tools &Manufacture 46(2006)51–5854chosen.Table 5summarizes these results.As the table shows,the ﬁnite element model provides solutions with less than 5%error for the designated mesh density levels.The selected mesh densities were used in all subsequent analyses.A summary of the element properties corresponding to the selected mesh density levels is presented in Table 6.5.Validation of selected mesh parametersThe general validity of the ﬁnite element mesh parameters obtained above for the ﬁxture–workpiece system was established by applying the same mesh guidelines to a different load–wall thickness combination.An identical experimental set-up was used as in Section 4.The wallthickness of the block was 8mm and a 375N clamping load was utilized.Table 7presents the corresponding exper-imental and FEA results.As the table shows,there is less than 5%error between the FEA and experimental values,–20.00%–18.00%–16.00%–14.00%–12.00%–10.00%–8.00%–6.00%–4.00%–2.00%0.00%1234567SMRT Size (Fixture)% E r r o r i n d C 1Fig.5.Percentage error for various workpiece density levels (planar tips).12345678SMRT Size (Fixture)–30.00%–25.00%–20.00%–15.00%–10.00%–5.00%0.00%% E r r o r i n d C 1Fig.6.Percentage error for various workpiece density levels (spherical tips).Table 5Predicted vs.measured results for selected mesh density levels250N 350N d C1(m m)d C2(m m)d C1(m m)d C2(m m)Planar Measured 26.520.536.228.9FEA 25.320.335.428.5%Error K 4.55K 0.91K 2.19K 1.55Spherical Measured 29.428.341.338.5FEA 28.727.739.438.8%ErrorK 2.34K 2.17K 4.530.71S.P.Siebenaler,S.N.Melkote /International Journal of Machine Tools &Manufacture 46(2006)51–5855thus establishing the adequacy of the selected mesh parameters for the given ﬁxture–workpiece system.6.Reaction force predictionAnother point of interest was the reaction forces between the locators and workpiece.Knowledge of reaction forces is important to ensure stability and equilibrium in the system.A series of experiments were run using the set-up shown in Fig.4to determine the reaction forces at Locators 1–3.Pressure-sensitive (Fuji Pre-scale)ﬁlm was used at each of the three locator–workpiece contacts to produce a color intensity map.The individual images were mapped into a density array via a regression analysis to determine the contact pressure [23].The area of the imprint was found using a photo-editing program,leading to the determination of the reaction forces.The mesh parameters that were established in Section 5and a coefﬁcient of friction of 0.18were used to predict reaction forces at the same locations.Table 8gives the results of the analysis.As can be seen from the table,FEA predictions are within 5%of the experimen-tal values thereby further validating the model.7.Effect of ﬁxture body complianceThe models described in the previous sections only took into account the workpiece and the ﬁxture tips.Most published analyses of ﬁxtures assume that the ﬁxture is rigid due to its considerably higher stiffness compared to that of the workpiece.Thus,these studies do not model the ﬁxture itself and cannot account for any deformation effects of the ﬁxture components.This paper,however,sought to investigate the contribution of ﬁxture compliance to the overall predicted workpiece deformation by modeling various ﬁxture elements.The components that were modeled in addition to the contact tips were the ﬁxture support blocks,base plate,and clamp supports as shown in Fig.7.A series of models were constructed incorporating various combinations of these components.The support blocks and base plate were constructed to be solid prismatic blocks with dimensions matching those in the physical set-up.The support blocks had dimensions 63.5mm !50.8mm !73.8mm.The steel base plate had dimensions of 305mm !305mm !15mm.The planar and spherical tip ﬁxture element dimensions were the same as those mentioned earlier in the paper.The ﬁxture tips were modeled as fastened to the support blocks via the vglue command of ANSYS w .The support blocks were similarly afﬁxed to the base plate and the bolt and dowel holes wereTable 6Mesh density parametersPlanarSpherical No.of WP elements 43807343WP element size (mm 3)65.2738.93No.of ﬁxture elements 539423,408Fixture element size (mm 3)0.540.32Contact element size (mm 3)1.500.12Table 7Model validation resultsd C1(m m)d C2(m m)PlanarFEA26.321.4Measured 27.322.3%Error K 3.56K 4.14SphericalFEA32.826.4Measured 33.927.7%ErrorK 3.17K 4.71Table 8Comparison of measured and predicted locator reaction forcesMeasured (N)FEA (N)%Diff.F L1(N)Spherical 2508986K 2.9350126121K 3.9Planar2508481K 4.0350117113K 3.8F L2(N)Spherical 2509895K 2.9350138133K 3.6Planar25010299K 3.1350145139K 4.5F L3(N)Spherical 250170177 4.1350250248K 0.9Planar250177173K 2.1350244243K0.6Fig.7.Fixture components.S.P.Siebenaler,S.N.Melkote /International Journal of Machine Tools &Manufacture 46(2006)51–5856not modeled.Models that included the base plate used the vglue command to afﬁx primary plane locating elements to the plate.For the models including the support blocks but not the base plate,the bottom surface of the blocks was constrained in all three translational degrees of freedom to simulate the blocks being fastened ﬁrmly to the base plate.The cylindrical clamp supports were modeled as solid cylinders that could only translate along the axis of the clamping force.The clamping pressure produced by the hydraulic pump was modeled as a uniformly distributed pressure across the area on the back surface of the clamp.FEA models of workpiece wall thicknesses of 7,8,and 9mm were used for the analysis.The loading conditions used are the same as those in Table 5.Workpiece deformation was also evaluated at the same locations as in the mesh density study.Results for the planar tip case are given in Table 9.The percent prediction error,averaged over both loading conditions and deformation locations,is given for FEA models including various ﬁxture com-ponents.Also given in the table are computational times relative to the model containing only the ﬁxture tips and workpiece.It is evident that modeling the additional individual ﬁxture elements improved the accuracy of the FEA only slightly.The complete ﬁxture model showed signiﬁcant improvement in the simulated results,yielding results within 1%of the experimental values.However,the complete model required 653%of the computational time needed by the model consisting of just the workpiece and ﬁxture tips.For the ﬁxture with spherical tips,modeling of ﬁxture components did not improve the accuracy of the results.The modeling of additional ﬁxture components gave a more accurate representation of the ﬁxture–workpiece interaction for the planar contact case.The deformation of the ﬁxture itself,while small in comparison with that of the workpiece,inﬂuenced the overall system compliance.The FEA showed that 2.4%of the measured deformation is actually deformation in the ﬁxture.The simulations showed that 22.7%of the ﬁxture compliance occurs in the tips and the remaining 77.3%in the support system.Thus,the original model only containing the workpiece and ﬁxture tips captured 98.1%of the overall system compliance.7.1.Signiﬁcance of support block complianceAn analysis was performed to see how changes in the ﬁxture compliance altered the overall system compliance.Complete ﬁxture models of the initial conﬁguration as well as cases for which the support blocks had different depths,D ,were run.The initial depth,D 0,is shown in Fig.8.Fig.9plots the percentage of system deformation occurring in the ﬁxture itself for various normalized values of D .It would be expected that thinner blocks would deﬂect more than larger ones,shifting more deformation to the ﬁxture.This assumption is conﬁrmed in the plot.8.ConclusionsThis paper focused on the factors inﬂuencing the prediction of workpiece deformation when using the ﬁnite element method.Speciﬁcally,it analyzed the effects of different ﬁnite element modeling parameters such as contact friction,mesh density and ﬁxture body compliance on the prediction of workpiece deformation.Predicted workpieceTable 9Effect of ﬁxture compliance:planar tip caseAvg.error (%)Time (%)Fixture tips 2.30100Support blocks 1.76153Clamp supports 1.52305Blocks and supports 1.69346Complete ﬁxture0.93653Fig.8.Support blockdepth.0.000.020.040.060.080.100.120.140.160.180.250.500.751D/D o d F /d T O TFig.9.Effect of support block compliance.S.P.Siebenaler,S.N.Melkote /International Journal of Machine Tools &Manufacture 46(2006)51–5857deformations and locator reaction forces were then experimentally veriﬁed.The simulation studies showed that models of the workpiece andﬁxture contacts based on surface-to-surface contact elements could predict workpiece deformations and reaction forces to within5%of the experimental values.The mesh density of the workpiece was found to be more vital to model accuracy than theﬁxture tip density.For theﬁxture–workpiece system analyzed in this paper,over98%of all system deformation could be captured by models containing only the workpiece andﬁxture tips.The remainder of system deformation is present in theﬁxture itself.The capturing of such compliance is possible by modeling the entireﬁxture body.However,a completeﬁxture model requires over six-fold computational time. AcknowledgementsThis work was funded in part by the Caterpillar Technical Center and a matching grant from the Georgia Research Alliance.References[1]Y.C.Chou,V.Chandru,M.M.Barash,A mathematical approach toautomatic conﬁguration of machiningﬁxtures:analysis and synthesis, ASME Journal of Engineering for Industry111(4)(1989)299–306.[2]E.C.DeMeter,Restraint analysis ofﬁxtures which rely on surfacecontact,ASME Journal of Engineering for Industry116(1993)207–215.[3]M.Y.Wang,D.M.Pelinescu,Contact force prediction and forceclosure analysis of aﬁxtured workpiece with friction,ASME Journal of Manufacturing Science and Engineering125(2)(2003)325–332.[4]R.P.Sinha,J.M.Abel,A contact stress model for multi-ﬁngeredgrasps of rough objects,Proceedings of the IEEE Conference on Robotics and Automation1990;1040–1045.[5]G.Xiuwen,J.Y.H.Fuh,A.Y.C.Nee,Modeling of frictional elasticﬁxture–workpiece system for improving location accuracy,IIE Transactions28(1996)821–827.[6]J.F.Hurtado,S.N.Melkote,A model for the prediction of reactionforces in a3-2-1machiningﬁxture,Transactions of NAMRI/SME26 (1998)335–340.[7]J.D.Lee,L.S.Haynes,Finite element analysis ofﬂexibleﬁxturingsystem,ASME Journal of Engineering for Industry109(2)(1987) 124–139.[8]R.J.Menassa,W.R.DeVries,Optimization methods appliedto selecting support positions inﬁxture design,Transactions of ASME,Journal of Engineering for Industry113(1991)412–418.[9]M.R.Rearick,S.Hu,S.Wu,Optimalﬁxture design for deformablesheet metalﬁxtures,Transactions of NAMRI/SME21(1993)407–412.[10]E.DeMeter,Fast support layout optimization,International Journal ofMachine Tools and Manufacture38(1998)1221–1239.[11]Y.J.Liao,S.J.Hu,D.A.Stephenson,Fixture layout optimizationconsidering workpiece–ﬁxture contact interaction:simulation results, Transactions of NAMRI/SME26(1998)341–346.[12]S.L.Xie,S.J.Hu,W.Li,A.Sudjianto,Fixture conﬁguration designusing a computer experiment,Proceedings of the ASME,Manufac-turing Science and Engineering11(2000)133–140.[13]J.Abou-Hanna,K.Okamura,Finite element approach to modelingparticulate bedﬁxtures,Journal of Manufacturing Systems11(1992) 1–12.[14]P.C.Pong,R.R.Barton,P.H.Cohen,Optimumﬁxture design,Proceedings of the Second Industrial Engineering Research Con-ference,1993pp.6–10.[15]P.Chandra,S.M.Athavale,S.G.Kapoor,R.E.DeVor,Finite elementbasedﬁxture analysis model for surface error prediction due to clamping and machining forces,Proceedings of ASME,Manufactur-ing Science and Technology,MED6.2(1997)245–252.[16]J.H.Yeh,F.W.Liou,Contact condition modeling for machiningﬁxture setup processes,International Journal of Machine tools and Manufacture39(1998)787–803.[17]Y.G.Liao,R.Khetan,R.Stevenson,An experimental investigationinto the deﬂection of aﬁxture–workpiece system,Transactions of NAMRI/SME28(2000)413–418.[18]S.Satyanarayana,Fixture–workpiece contact modeling for a com-pliant workpiece,MS Thesis,Mechanical Engineering,Georgia Institute of Technology,2001.[19]S.Satyanarayana,S.N.Melkote,Finite element modeling ofﬁxture–workpiece contacts:single contact modeling and experimental veriﬁcation,International Journal of Machine Tools and Manufacture 44(2004)903–913.[20]B.M.Bazrov,A.I.Sorokin,The effect of clamping sequence onworkpiece mounting accuracy,Soviet Engineering Research2(10) (1982)539–543.[21]P.Chandra,S.M.Athavale,R.E.DeVor,S.G.Kapoor,Effect ofpreloads on the surfaceﬂatness duringﬁxturing ofﬂexible work-pieces,Proceedings of the First S.M.Wu Symposium,vol.2,1996pp.146–152.[22]A.Raghu,S.N.Melkote,Analysis of the effects ofﬁxture clampingsequence on part location errors,Journal of Machine Tools and Manufacture44(2004)373–382.[23]S.Siebenaler,Finite element approach to modeling deformation in aﬁxture–workpiece system,MS Thesis,Mechanical Engineering, Georgia Institute of Technology,2003.S.P.Siebenaler,S.N.Melkote/International Journal of Machine Tools&Manufacture46(2006)51–58 58。

有限元外文翻译

DEVELOPMENT OF A METHODOLOGY FOR DETERMINATION AND ANALYSIS OF THERMAL DISPLACEMENTS OF MACHINE TOOLS USING ELEMENTS METHOD FINITE AND ARTIFICIAL NEURAL NETWORKSRomualdo Figueiredo de Sousa, Instituto Federal da Paraíba, Av. Primeiro de maio, 720, Bairro: Jaguaribe. João Pessoa, CEP 58015-430, Campus Cajazeiras-PB, Brasil. engfsousa@.brFrancisco Augusto Vieira da Silva, Universidade Federal da Paraíba, Centro de Tecnologia, Bloco “F” Campus I – CEP 58.059-900 – João Pessoa – PB, Brasil. francisco.avs@João Bosco de Aquino Silva, Universidade Federal da Paraíba, Centro de Tecnologia, Bloco “F” Campus I –CEP 58.059-900 – João Pessoa – PB, Brasil. jbosco@ct.ufpb.brJosé Carlos de Lima Júnior, Universid ade Federal da Paraíba, Centro de Tecnologia, Bloco “F” Campus I –CEP 58.059-900 – João Pessoa – PB, Brasil. limajr@ct.ufpb.br利用有限元法和人工神经网络技术测定和分析机床热位移的方法一種方法的測定的和機床熱利用移動分析單元法有限和神經網絡分析發展菲格雷多羅穆阿爾德索薩，聯邦研究所DA帕拉伊巴，大道。

车辆专业外文文献翻译基于有限元方法的陀螺仪的盘型

基于有限元方法的陀螺仪的盘型制动系统的尖叫分析作者：Jaeyoung Kang【摘要】本文对一辆车的制动系统中旋转阀瓣接触两个固定垫的动力失稳性进行了研究。

在现行的近似几何中，盘被有限元分析法以帽盘型结构为模型。

从参考坐标系和移动坐标系见的坐标变换，对盘和垫之间的接触运动学进行了阐述。

通过引入统一的二维网的方法来构造阀瓣相应的陀螺矩阵。

陀螺仪的非保守性制动系统的动力不稳定性是对系统参数的数值预测。

结果表明, 尖叫声倾向于转速，转速取决于参与尖叫声模式下的振动模式。

而且,它强调摩擦系数的负斜率对在盘的面内扭转模式下产生尖叫声起着至关重要的作用。

【关键词】陀螺仪；盘型制动；制动尖叫；耦合模式1.介绍盘式制动尖叫已经被许多学者研究了数十年。

通过对尖叫机械的研究积累了许多有价值的信息。

Kinkaid等[1]提供了关于各种盘型制动尖叫研究的概述。

Ouyang 等[2]发行了以汽车盘型制动尖叫的数值分析为集中研究的评论性文章。

他们显示一个主要研究制动尖叫的方法，是线性稳定分析。

从线性化的运动微分方程来看,真正的部分特征值被计算出来，用于决定均衡的稳定性。

在文献中，有两个关于线性尖叫分析的主要方向：静态平稳的复杂特征值分析——滑动平稳[3–8]和旋转制动系统的稳定性分析[9–12,14]。

固定盘和垫的静态的滑动稳定的稳定性分析提供尖叫原理作为频繁摩擦领域里的合并模式的特性。

Huang等[6]使用本征值摄动法发展必要的条件没有直接的本征结果。

Kang等[7]推导了盘对之间的合并模式的封闭解。

由于固定盘假设,有限元(FE)方法被容易地应用于上面提到的评论性文章[2]. 同样的，Cao 等[13]从一个有移动垫和固定盘的FE盘型制动模型模型研究了移动荷载效应，因此,陀螺仪的影响被忽视了。

Giannini等[15,16]验证其合并模式行为,通过使用实验尖叫频率作为尖叫开始。

另一方面，旋转盘型制动的稳定性已经调查了分析的方法。

麻花钻的建模和有限元分析毕业设计论文精品

麻花钻的建模及强度分析[摘要]：采用三维建模软件建立麻花钻的三维模型，分析刀具在工作时的受力情况。

应用有限元软件对麻花钻进行模态分析，研究其结构的震动特性。

利用de fo r m软件对麻花钻的工作过程进行模拟仿真。

[关键词]：麻花钻；三维建模；an s ys分析；de fo rm仿真Twist drill modeling and the analysis of its intensionJunbing Wu（Grade07,Class 3，Major mechanical design and manufacturing automation ，school of Mechanical Engineering Dept.，Shaanxi University of Technology，Hanzhong 723003，Shaanxi）tutor: Hongling HouAbstract:This artical introduced the 3D modeling method of twist drill and the anal ysis of t wist drill when it behaves. Finite element software for modal analysis Twist. Deform software using process simulation work.Key Words: twist drill；ansys；deform；simulation毕业设计（论文）原创性声明和使用授权说明原创性声明本人郑重承诺：所呈交的毕业设计（论文），是我个人在指导教师的指导下进行的研究工作及取得的成果。

尽我所知，除文中特别加以标注和致谢的地方外，不包含其他人或组织已经发表或公布过的研究成果，也不包含我为获得及其它教育机构的学位或学历而使用过的材料。

对本研究提供过帮助和做出过贡献的个人或集体，均已在文中作了明确的说明并表示了谢意。

有限元分析软件外文翻译

南京林业大学本科毕业设计（论文）外文资料翻译翻译资料名称(外文)Stress analysis of heavy duty truck chassis as apreliminary data for its fatigue life predictionusing FEM翻译资料名称(中文)利用重型载货汽车的有限元应力分析的初步数据预测其疲劳寿命院（系）：汽车与交通工程学院专业：机械制造及其自动化（汽车设计方向）姓名：学号：指导教师：完成日期： 2012/5/31利用重型载货汽车的有限元应力分析的初步数据预测其疲劳寿命Roslan Abd Rahman, Mohd Nasir Tamin, Ojo Kurdi马来西亚工程大学机械工程系81310 UTM, Skudai,Johor Bahru摘要本文对一重型货车底盘做了应力分析。

应力分析能够确定零件的最大受力点，是分析零部件疲劳研究和寿命预测的重要手段。

前人已有用商用有限元软件ABAQUS软件对底盘模型进行分析的。

本次研究的底盘长12.35米，宽2.45米，材料是ASTM低合金钢710（3级），屈服极限552MPa，抗拉强度620MPa。

分析结果显示，最大应力点出现在底盘与螺栓连接的空缺处，最大应力为386.9MPa，底盘的疲劳破坏将会从最大应力点开始向车架各部位蔓延。

关键字：应力分析，疲劳寿命预测，货车底盘1.0简介在马来西亚，很多货车的车架寿命都有20多年，20多年架就会有使用安全的问题。

因此，为了确保底盘在工作期间的安全性能，就有必要对底盘作疲劳研究和寿命预测。

利用有限元法作应力分析能够确定受最大应力的关键点，这个关键点是导致底盘疲劳损伤的因素之一。

应力的大小能够预测底盘的寿命，所以可以根据应力分析的结果精确地预测底盘的寿命，应力分析越精确，底盘寿命预测的越合理。

本文是用商用有限元软件ABAQUS 软件完成底盘应力分析的。

汽车工业（汽车总成及各部件）在马来西亚的工业中占据非常重要的地位。

地下工程有限元分析流程

地下工程有限元分析流程Finite element analysis is a powerful tool in the field of underground engineering. It allows engineers to simulate and analyze complex interactions between soil, structures, and groundwater. By breaking down a complex system into smaller, more manageable elements, finite element analysis can provide valuable insights into how a structure will behave under various conditions. This analysis process involves several key steps, each of which is critical to ensuring the accuracy and reliability of the results.有限元分析是地下工程领域中一种强大的工具。

它能够使工程师模拟和分析土壤、结构和地下水之间复杂的相互作用。

通过将复杂系统分解为更小、更易管理的元素，有限元分析可以为工程师提供有价值的见解，让他们了解结构在各种条件下的行为。

这个分析过程包括几个关键步骤，每个步骤对确保结果的准确性和可靠性至关重要。

The first step in the finite element analysis process is to create a mesh. This involves dividing the structure and surrounding soil into a finite number of elements or nodes. The size and shape of these elements play a crucial role in determining the accuracy of theanalysis. A finer mesh can provide more detailed information but requires more computational resources, while a coarser mesh may lead to less accurate results. Engineers must strike a balance between mesh density and computational efficiency to ensure the analysis is both accurate and manageable.有限元分析过程中的第一步是创建网格。

钻孔法检测残余应力的有限元分析

钻孔法检测残余应力的有限元分析陈聪【期刊名称】《吉首大学学报（自然科学版）》【年(卷),期】2012(033)001【摘要】释放系数是钻孔法测量残余应力的重要指标之一.采用有限元分析软件abaqus研究了释放系数与钻孔位置和钻孔深度之间的关系,并得到了对应的拟合曲线.通过与已有的研究结果进行对比分析,表明了该研究方法和研究结果是可以满足工程需要的.%Releasing coefficient is one of the most important index when applying hole-drilling method to measure residual stress.In this paper,the effect of the position of strain gages and the depth of drilled hole on the releasing coefficient are studied by using the finite element method （FEM）,and the corresponding fitted curves are pared with the previous research results,the method and results discussed in this paper is valid.【总页数】5页(P56-60)【作者】陈聪【作者单位】湖南省特种设备检验研究院湘西分院,湖南吉首416000【正文语种】中文【中图分类】TG404【相关文献】1.钻孔法检测残余应力技术中有关参数的数值计算分析 [J], 赵冲久;邓雷飞;田双珠2.基于钻孔法检测预应力混凝土梁有效应力的有限元分析 [J], 徐满意;林高杰;孙熙平3.基于逐层钻孔法的闪光焊钢轨轨底残余应力分析 [J], 罗雁云;唐吉意;朱茜;陆可人;张天琦4.反向钻孔法应用于工件内表面残余应力测量的研究 [J], 马小明;欧清扬5.钻孔法测量焊接残余应力误差因素分析 [J], 甘世明;韩永全;陈芙蓉因版权原因，仅展示原文概要，查看原文内容请购买。

基于风载、地震载荷下的钻机底盘有限元分析

Internal Combustion Engine&Parts0引言GF-MX50锚固旋喷钻机（以下简称钻机）适用于水利、铁路、公路边坡及工、民建筑等软地基加固、防渗防漏旋喷桩施工工艺等。

由于该钻机作业时属于野外作业，工况比较恶劣，也会有突发事件包括大风、地震的发生，为了应对突发事件的结构设计的合理性，就有必要对钻机的主要部件之一的底盘进行在大风、地震状态下的应力分析。

因此，分析与掌握钻机主要承载部件的底盘特性是解决钻机恶劣环境下工作的首要任务。

进入21世纪后，我国相继研发了多款新型岩心钻机，但是在地质钻杆的拧卸、移送和摆放等自动化发展上始终没有实质性突破[1-2]。

TSJ-2000水源钻机主要用于井矿盐钻井施工，由于自带底座结构简单低矮，已不能满足施工工艺要求，于是重新设计底座，底座设计除满足基本的受力分析和承载力校核之外[3-4]，还需要对钻机底座的固有频率和振动形态进行分析，因为钻机工作过程中，底座上部设备运动激励使其产生共振，会削弱钻机整体的结构强度，影响结构安全以及人员的工作环境[5]。

上述文献虽然研究较全面，但是没有涉及到风载、地震载荷下的钻机底盘的仿真分析和钻机底盘普通载荷下的疲劳分析，因而存在一定问题。

钻机底盘主要是由槽钢焊接而成，在作业的时候由于环境的恶劣会产生变形，对钻机的正常作业造成破坏性的影响。

本文将从风力8级、地震7级恶劣环境下两个方面对钻机底盘进行有限元分析。

分析出钻机底盘的最大应力、最大挠度。

并对钻机底盘进行疲劳分析得出钻机的寿命。

该论文对工程机械强度提高的结构改进和材料的改进提供了重要的参考价值。

1钻机底盘的数学模型的建立与受力分析钻机的实体模型图如图1所示，主要由主梁、升举装置、底盘、底座等组件构成。

钻机的底盘的受力主要来自于主梁工作时的反力、以及底盘4个支腿上承受的重力、风载荷、地震载荷。

受力图如图2所示，F1为反力、F2为风载荷、F3（1-4）为地震载荷在每个支腿的分力，G（1-4）为钻机底盘所承受的重力在每个支腿的分力。

外文翻译用有限元方法分析齿轮传动旋耕机应力中文版

用有限元方法分析旋耕机传动齿轮应力[摘要]旋耕机是由拖拉机动力输出轴带动其回转运动的为了混合土壤一种耕地工具。

通过使用旋耕机混合土壤，土壤压实度在很大程度上减少了。

由于它的众多好处，如今旋耕机在我国应用的越来越广泛。

旋耕机的结构组成包括一个能够90度的改变来自拖拉机输出轴方向的齿轮箱，几个传动齿轮，和一个水平放置从而能够混合土壤转子轴。

转子轴上面有能够破碎并混合土壤的刀片。

特别是由为一些强烈震动、大量输出的无用功、一些地区土壤质量、设计制造误差和错误使用条件的影响，使得刀具刀片和传输齿轮容易发生变形。

对建设和传动部件，为了能更好的了解这些部分失效的原因，应该要更精确的确定应力分布情况。

此次研究的旋耕机由本地制造商设计和制造，其中应用了三维制图软件对旋耕机传动齿轮进行了三维实体造型,并根据旋耕机的工作条件，运用有限元分析软件对其结构进行应力仿真。

仿真结果评估显示，根据齿轮的屈服压力，得出齿轮无故障工作。

并且，齿轮的工作安全系数也参照仿真结果计算得出。

关键词：旋耕机；应力分析；有限元分析方法1．介绍旋耕机是一种用于耕地领域和水果农业园的耕作机。

它具有很强的切割，混合表层土壤和直接准备苗床的功能。

此外旋耕机的混合性功能是犁的7倍。

旋耕机与拖拉机的三点联动装置相连，依靠拖拉机的动力输出轴驱动。

它的横向放置的轴能够将从动力输出轴传递到第二个齿轮箱的方向改变90度，同时转子轴随着第二个齿轮箱运动。

旋耕机齿轮箱至少包括箱体、输入轴、输出轴、主动锥齿轮、从动锥齿轮。

输入轴和输出轴均架设在箱体上，主动锥齿轮固定在输入轴的顶端，其特征在于：从动锥齿轮有两只，相对设置并分别套接在输出轴上，从动锥齿轮与输出轴轴向固定但径向不固定，主动锥齿轮与两只从动锥齿轮常啮合，牙嵌离合器键联接在两只从动锥齿轮之间的输出轴上，拨档杆架设在箱体上，它的拨头插设在牙嵌离合器中，牙嵌离合器在拨档杆的拨动下与左侧从动锥齿轮啮合或与右侧从动锥齿轮啮合。

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Studies in dynamic design of drilling machine using updated finite element modelsAbstractThe aim of the present work is to develop updated FE models of a drilling machine using analytical and experimental results. These updated FE models have been used to predict the effect of structural dynamic modifications on vibration characteristics of the drilling machine. Two studies have been carried out on the machine. In the first study, modal tests have been carried out on a drilling machine using instrumented impact hammer. Modal identification has been done using global method of modal identification. For analytical FE modeling of the machine, a computer program has been developed. The results obtained using FEM, have been correlated with the experimental ones using mode shape comparison and MAC values. Analytical FE model has been updated, with the help of a program, which has been developed using direct methods of model updating. In the second study, modal testing has been carried out using random noise generator and modal exciter. Global method has been used for modal identification. Analytical FE modeling has been done using I-DEAS software. Correlation of FE results with the experimental ones has been carried out using FEMtools software. Updating of the analytical FE model has also been done using the above software, based on an indirect technique viz. sensitivity based parameter estimation technique. The updated FE models, obtained from both the studies have been used for structural dynamic modifications (SDM), for the purpose of dynamic design and the results of SDM predictions are seen to be reasonably satisfactory.Article Outline1. Introduction2. Modal testing and identification3. Finite element formulation of drilling machine4. Comparison of analytical FE and experimental results (model correlation)5. Finite element model updating6. SDM studies using updated models for dynamic design7. ConclusionsReferences1. IntroductionDynamic design aims at obtaining desired dynamic characteristics in machines and structures, which may include shifting of natural frequencies, desired mode shapes and vibratory response. The ultimate objectives are to have a quieter and more comfortable environment, higher reliability and better quality of product. The conventional dynamic design is basically hit and trial method in which we try to achieve desired dynamic characteristics by making several prototypes. The disadvantage of this technique is that actual design cycle takes a lot of time and therefore it is not cost effective. However, model updating based dynamic design saves design cycle time as well as reduces the cost involved. Various tools used for updating based dynamic design are: experimental modal analysis (EMA) including modal testing and modal identification, model updating and structural dynamic modification.Ewins [1]and Maia and Silva [2]have explained the basic concepts of modal testing, which is an experimental approach to obtain mathematical model of a structure. In a modal test, the structure under test is excited either by an impact hammer or by a modal exciter, and the response of the structure is recorded at several experimental points, in the form of frequency response functions (FRFs), using a dual channel FFT analyzer. The experimental modal model gives information about the natural frequencies, corresponding mode shapes and modal damping factor and is useful for model updating. The model updating techniques helps us to bring analytical finite element models closer to real systems. In model updating an initial analytical FE model constructed for analyzing the dynamics of a structure is refined or updated using test data measured on actual structure such that the updated model describes the dynamic properties of the structure more correctly. The inaccuracies in FEM, when applied to dynamic problems are due to uncertainties in boundary conditions and structural damping etc.Friswell and Mottershead [3] have discussed the finite element model updating in structural dynamics. Baruch and Bar-Itzhack and Baruch [4] and [5] considered analytical mass matrix to be exact and developed a direct method for updating using test data. Berman and Nagy [6]developed a method of model updating, which uses measured modes and natural frequencies to improve analytical mass and stiffness matrices. Structural dynamic modification (SDM) techniques [7]and [8]are the methods by whichdynamic behaviour of the structure is improved by predicting the modified behaviour brought about by adding modifications like those of lumped masses, rigid links, dampers etc. Thus the dynamic design using updated model is expected to be helpful in order to predict accurately and quickly, the effect of possible modifications on the dynamic characteristics of the structure at computer level itself, thus saving time and cost.Sestieri [7]has discussed SDM application to machine tools and engines. Kundra [8]gave the method of structural dynamic modification via models. Modak [9] has discussed SDM predictions using updated FE model for an F-structure. He used constrained nonlinear optimization method for updating of a machine tool using stiffness parameters at the boundary [10]. The present paper deals with the FE model updating using direct as well as indirect method, and to use this updated FE model for dynamic design based on SDM predictions of a machine tool viz. a drilling machine. Two different studies are reported using different techniques for analytical and experimental analysis and for updating. Various objectives with which the present research work has been carried out are• To develop updated FE models of a complex structure like that of a drilling machine and to use these updated models to predict the effect of various modifications on modal properties of the machine.• To see whether hammer excitation yields good results for fairly complex structures like drilling machine or not, and to compare these results with those obtained from modal exciter.• To analyze the results of SDM predictions obtained using the updated models derived in the studies.2. Modal testing and identificationIn the two studies mentioned earlier, different techniques have been used, for modal testing and identification. In the first study, impact hammer is used to excite the drilling machine structure, at various points as shown in Fig. 1 and Fig. 2. Response is taken at a fixed point with the help of an accelerometer.(12K)Fig. 1. Experimental setup (Study 1).(4K)Fig. 2. Hammer excitation locations.In the present study, the drilling machine is excited at 30 locations and therefore, 30 FRFs are obtained. These FRFs are recorded in the form of inertance. The experimental FRFs, thus obtained are transferred to computer. Modal identification or modal parameter extraction consists of curve fitting a theoretical expression for an individual FRF to the actual measured data obtained. The experimental FRFs are analyzed by GRF-M method using modal analysis software ICATS [11] to obtain modal parameters of the drilling machine. In the second study, the machine tool structure has been excited at the base at point 28, referring to Fig. 2, using modal exciter and response has been measured at various points using piezoelectric accelerometers. The modal identification of the FRFs, thus measured has been carried out using global method GRF-M method in ICATS software.Table 1compares the experimental natural frequencies obtained from both the methods, which shows minor differences in the two modal frequenciesTable 1.Mode110.29 Hz8.67 HZ0.95311.20 Hz8.79 Hz0.946Mode 265.14 Hz47.34 HZ0.90163.37 Hz44.40 Hz0.9063. Finite element formulation of drilling machineSeveral books have given the basic concepts of finite element analysis, some of them are: Zienkiewicz [12] and Bathe [13].The drilling machine structure is very complicated with different mountings and accessories. Therefore exact modeling and analysis of the actual structure is difficult and it takes more computational effort. However for analytical FE analysis, simplified model of drilling machines has been considered. In study 1, the finite element modelling has been done using a program developed in MATLAB. Beam elements have been used for the analysis. The joints and boundary conditions are considered to be rigid and influence of structural damping on modal model parameters, is ignored. The relevant data used for the drilling machine is given below:25 mm pillar type, height = 1.655 m, mass density = 7800 kg/m3, Young’s modulus= 200 Gpa, number of nodes = 30, number of elements = 29, number of nodes per element = 2, degrees of freedom per node = 3.Fig. 3shows the structure of the drilling machine with the node numbers given for study 1.(7K)Fig. 3. Drilling machine structure for FE analysis.The eigenvalues and eigenvectors have been calculated. The analytical FE model of the structure consists of 90 ×90-size mass and stiffness matrices (30 ×3, 30 nodes and 3 d.o.f. per node). But by experiment only 30 coordinates can be measured. Therefore FE model has been reduced using Guyan [14] reduction method with the help of a program developed in MATLAB.In study 2, the finite element modelling has been done using I-DEAS software. The model has been made using beam mesh. Although the FE model has been simplified but the beam elements has rotational degree of freedom, which cannot be measured experimentally. Therefore the FE model needs to be reduced. The FE model has been reduced using model reduction utilityin FEMtools software. Fig. 4 and Fig. 5 shows the mode shape animation for the first and second mode respectively, using I-DEAS software.(31K)Fig. 4. Mode shape animation (first mode).(23K)Fig. 5. Mode shape animation (second mode).4. Comparison of analytical FE and experimental results (model correlation)The first stage of any reconciliation exercise is to determine how closely the experimental and analytical models correspond. If we are unable to obtain a satisfactory degree of correlation between the initial analytical FE model and the test data, then it is extremely unlikely that any form of model updating will succeed. Thus, a successful correlation is crucial for the success of model updating. Table 1gives the comparison between experimental and analytical natural frequencies. There are differences between analytical FE model predictions and experimental results. Thus the FE models need to be updated. However, the differences between the corresponding results of both studies are minor.Apart from natural frequency comparison (as given in Table 1), another method of model correlation is mode shape comparison. To compare the mode shapes, we plot the deformed shapes of the structure for a particular mode, using experimental as well as analytical model. These mode shapes are plotted side-by-side for quick comparison. Mode shape corresponding to second mode is shown in Fig. 6, using ICATS software. It shows a fairlygood level of correlation between the experimental and analytical FE model.(87K)Fig. 6. Mode shape comparison.Several researchers have developed techniques for quantifying the comparison between measured and predicted mode shapes. As an alternative to the graphical approach, Model Assurance Criterion i.e. MAC, [15]) is a widely used technique to estimate the degree of correlation between mode shape vectors. This provides a measure of the least squares deviation or ‘scatter’ of the points from the straight-line correlation. The MAC between a measured and analytical mode is:(1)wherem andarepresents measured or experimental and analytical modeshapes respectively. MAC is a scalar quantity whose value is between 0 and 1. A value of MAC close to 1 shows a good degree of correlation between experimental and analytical FE model. We can see in Table 1 that the MAC numbers are close to 1, though somewhat lower for the second mode. Table 1 also shows that the results obtained from both the studies are quite close to each other.5. Finite element model updatingModel updating can be defined as “the process of correcting the numerical values of individual parameters in a analytical FE model using data obtained from an associated experimental model such that the updated model correctly describes the dynamic properties of the subject structure”.Various model updating methods can be classified into two major groups: • Direct matrix methods• Indirect or iterative methodsDirect methods are capable of reproducing measured data exactly, but they provide no opportunity for the user to select parameters for updating. Here parameter means any physically realizable quantity like Young’s modulus, Poisson’s ratio, mass density etc. When using the direct methods, the entire stiffness and mass matrices are updated in a single(non-iterative) solution step. Consequently any physical meaning, which the initial finite element model might have possessed, is lost in the updating process.Techniques like the indirect methods, allow the updating parameters to be selected. So, considerable physical insight is required if the model is to be improved, not only in its ability to reproduce test results, but also in interpreting the parameters physically. Methods in this second group are iterative and, as such, considerably more expensive of computer effort.Two studies have been carried out for model updating and computer programs for the same were developed in the present work using MATLAB. In the first study, two direct methods are applied to update the analytical FE model of the drilling machine structure.Baruch and Bar-ltzhack [4] and Baruch [5] considered the mass matrix of the analytical model to be exact. The measured eigenvectors are corrected by using the relation:(2)The stiffness matrices of the analytical FE model after updating is given as:K=K a-K a T M a+M a T K a+M a T K a T M a+M aΛT M a(3)uBerman and Nagy [6] used a method similar to that of Baruch. They update mass and stiffness matrices while the mass matrix is updated to ensure the orthogonality of the exact FE model modes. The mass matrix is updated as:(4)(5) The stiffness matrix is updated using following equation:(6) The updated mass matrix obtained will be symmetric and stiffness matrix will be close to that of exact stiffness matrix. Results obtained fromBaruch and Berman–Nagy model updating methods are tabulatedin Table 2. It is clear from Table 2, that the updated model reproduces the measured frequencies. After updating, MAC values have been calculated again using Eq. It can be observed that updated MAC values show some improvement over the initial MAC values.Table 2.Comparison of experimental and updated FE frequencies and MAC valuesModenumberStudy 1Study 2Measured frequency Baruch method Berman method MeasuredfrequencySensitivitymethodUpdatedfrequencyMACUpdatedfrequencyMACUpdatedfrequencyMACMod e 18.67 Hz8.67 Hz0.9258.67 Hz0.9348.79 Hz8.79 Hz0.947Mod e 247.34 Hz47.34 Hz0.96647.34 Hz0.94744.40 Hz44.43 Hz0.913The results after updating have been tabulated in Table 2. It clearly shows that after updating, the updated FE model closely represents the actual machine tool structure. It also shows that MAC values have also been improved after updating.6. SDM studies using updated models for dynamic designStructural dynamic modification (SDM) techniques are methods by which dynamic characteristics of the structure can be improved by adding the modifications like changing mass, spring, damping etc. The mass modification has been considered here for predicting dynamic characteristics using updated FE model.A mass modification on drilling machine is introduced in the form of a lumped mass of 14.3 kg at the top of the vertical pillar, i.e. node 20 as in Fig. 3. The modal test for the mass modified machine is carried out by Modak [10], using impact hammer for excitation. The FRFs are analyzed in ICATS in order to obtain an experimental estimate of the altered dynamic characteristics of the drilling machine, as given in Table 3.Table 3.Comparison of measured and predicted frequencies, after mass modification, using updated FE modelMode no.MeasuredfrequenciesSDM prediction using updated FE modelBaruch’s method Berman and Nagy’s method Sensitivity method18.37 Hz8.34 Hz8.17 Hz8.40 Hz246.05 Hz47.15 Hz46.96 Hz43.20 HzThe effect of the same mass modification on the dynamic characteristics of the drilling machine has also been predicted by updated FE model. Table 3 gives a comparison of the predictions based on the updated FE models obtained by direct methods of Baruch, Berman and Nagy and by indirectmethod based on sensitivity analysis, with that of the measured modified characteristics.It is seen from the Table 3 that the updated FE model predictions of the natural frequencies are quite close to the measured value of natural frequencies. This shows the capability of the updated FE model to accurately predict the effect of structural modifications on the dynamic properties of the structure. Now, this updated FE model has been further used to predict, at computer level, the effect of various mass modifications on the structural dynamics of the drilling machine, for the purpose of dynamic design.The mass modification can bring about significant changes in the natural frequencies of a structure. For predicting the effect of modifications using updated FE model, modification at node 20 and node 25, on the drilling machine has been considered. The effects on FRFs due to these modifications have been shown in Fig. 8and Fig. 9respectively. The values of the first two natural frequencies have been predicted using updated FE models and MODIFY module of ICATS software and are shown in Table 4and Table 5.(33K)Fig. 8. Regenerated FRF due to mass modification at node 20.(29K)Fig. 9. Regenerated FRF due to mass modification at node 25.Table 4.Predicted natural frequencies after mass modification using 20 kg at node 20 (PanelA), predicted natural frequencies after mass modification using 40 kg at node 20 (PanelB)Comparisons of SDM predictions using updated FE modelBaruch method Berman method Sensitivity method ICATS MODIFY Measured Frequencies Panel AMass modification of 20 kg8.22 Hz7.99 Hz8.3 Hz8.2 Hz8.3 Hz47.08 Hz46.83 Hz42.87 Hz47.1 Hz42.8 HzPanel BMass modification of 40 kg7.83 Hz7.45 Hz7.76 Hz7.75 Hz7.8 Hz46.86 Hz46.44 Hz41.27 Hz46.6 Hz41.3 HzTable 5.Predicted natural frequencies after mass modification using 20 kg at node 25 (PanelA), predicted natural frequencies after mass modification using 40 kg at node 25 (PanelB)Comparisons of SDM predictions using updated FE modelBaruch method Berman method Sensitivity method ICATS MODIFY Measured frequenciesPanel AMass modification of 20kg8.34 Hz8.44 Hz8.41 Hz8.35 Hz8.4 Hz 42.24 Hz43.74 Hz41.67 Hz42.2 Hz41.6 HzComparisons of SDM predictions using updated FE modelBaruch method Berman method Sensitivity method ICATS MODIFY Measured frequenciesPanel BMass modification of 40kg8.03 Hz8.21 Hz8.04 Hz8.1 Hz8.1 Hz38.89 Hz41.02 Hz39.67 Hz39.15 Hz39.5 Hz7. ConclusionsComparison of results obtained from experimental modal analysis and FE models of a drilling machine, indicate that its finite element models need to be updated. This is necessary in order to predict dynamic behavior of the complex structure with an acceptable accuracy.An experimentation involving modal testing has been carried out on the drilling machine using impact hammer as well as modal exciter. It has been observed that both impact hammer and modal exciter yield good results for fairly complex structures like drilling machine.Analytical FE model has been updated in the light of experimental data using direct as well as indirect methods. Both the methods give results, which are fairly close when used for predicting results of SDM attaching additional mass on the machine at different locations. The predicted results have been validated by comparison with measured results and are seen to be fairly accurate in particular for the indirect method using sensitivity analysis.References[1]D.J. Ewins, Modal Testing: Theory and Practice, John Willey and Sons, New York (2000).[2] N.M.M. Maia and J.M.M. Silva, Theoretical and Experimental Modal Analysis, John Willey and Sons, New York (1997).[3]M.I. Friswell and J.E. Mottershead, Finite Element Model Updating in Structural Dynamics, Kluwer Academic Publishers, Dordrecht (1995).[4] M. Baruch and I.Y. Bar-ltzhack, Optimal weighted orthogonalization of measured modes, AIAA Journal16 (1978), pp. 346–351.[5] M. Baruch, Optimisation procedure to correct stiffness and flexibility matrices using vibration test data, AIAA Journal16 (1978), pp. 1208–1210.[6]A. Berman and E.J. Nagy, Improvement of a large analytical model using test data, AIAA Journal21 (1983), pp. 1168–1173.[7] A. Sestieri, SDM application to machine tools and engines, Sadhana 25 (2000), pp. 305–317.[8] T.K. Kundra, Structural dynamic modification via model, Sadhana25 (2000), pp. 261–276.[9]S.V. Modak, Studies in Finite Element Model Updating and Application to Dynamic Design, Ph.D. Thesis, Department of Mechanical Engineering, IIT Delhi, 2001.[10]S.V. Modak, T.K. Kundra, B.C. Nakra, Dynamic design of machine tool structures using an updated model Pro. IMAC- XX, 2002, pp. 1489–1494.[11] ICATS Reference Manual, Imperial College, London, 1996.[12]O.C. Zienkiewicz, The Finite Element Method in Engineering Science, McGraw-Hill Publishing Company, London (1977).[13] K.J. Bathe and E.J. Wilson, Numerical Methods in Finite Element Analysis, Prentice-Hall, Englewood Cliffs, NJ (1982).[14] R.J. Guyan, Reduction of stiffness and mass matrices, AIAA Journal 3 (1965), p. 380.[15]R.L. Allemang, BD.L. Rown. A correlation coefficient for modal vector analysis, Proc. 1st IMAC, 1982, pp. 110–116.[16] FEMtools Manual Version 2.0, Dynamic design solutions, 2000.Corresponding author. Steam Turbine Engineering, TCGT Division, Bharat Heavy Electricals Limited, Hyderabad-502032, India译文利用有限元模型对钻机进行动态分析的研究摘要现在的工作的目的是使用分析和实验的结果发展和改进钻机的有限元分析模型，这种有限元分析已经用在监测将钻机的工作特性修改后对钻机动态的结构的影响；对钻机将有两个研究就进行。