中型卡車驅(qū)動(dòng)橋殼設(shè)計(jì)及有限元分析含開題報(bào)告及文獻(xiàn)綜述、任務(wù)書
中型卡車驅(qū)動(dòng)橋殼設(shè)計(jì)及有限元分析含開題報(bào)告及文獻(xiàn)綜述、任務(wù)書,中型,卡車,驅(qū)動(dòng),設(shè)計(jì),有限元分析,開題,報(bào)告,講演,呈文,文獻(xiàn),綜述,任務(wù)書
附錄1：外文翻譯
CAE的技術(shù)種類有很多，其中包括有限元法,邊界元法,有限差法等。每一種方法各有其應(yīng)用的領(lǐng)域，而其中有限元法應(yīng)用的領(lǐng)域越來越廣，現(xiàn)已應(yīng)用于結(jié)構(gòu)力學(xué)、結(jié)構(gòu)動(dòng)力學(xué)、熱力學(xué)、流體力學(xué)、電路學(xué)、電磁學(xué)等。
ANSYS軟件是融結(jié)構(gòu)、流體、電場、磁場、聲場分析于一體的大型通用有限元分析軟件。由世界上最大的有限元分析軟件公司之一的美國ANSYS開發(fā)，它能與多數(shù)CAD軟件接口，實(shí)現(xiàn)數(shù)據(jù)的共享和交換，如Pro/Engineer, NASTRAN, Alogor, I－DEAS, AutoCAD等，是現(xiàn)代產(chǎn)品設(shè)計(jì)中的高級(jí)CAE工具之一。
ANSYS有限元軟件包是一個(gè)多用途的有限元法計(jì)算機(jī)設(shè)計(jì)程序，可以用來求解結(jié)構(gòu)、流體、電力、電磁場及碰撞等問題。因此它可應(yīng)用于以下工業(yè)領(lǐng)域：航空航天、汽車工業(yè)、生物醫(yī)學(xué)、橋梁、建筑、電子產(chǎn)品、重型機(jī)械、微機(jī)電系統(tǒng)、運(yùn)動(dòng)器械等。
有限元分析（FEA，F(xiàn)inite Element Analysis）的基本概念是用較簡單的問題代替復(fù)雜問題后再求解。它將求解域看成是由許多稱為有限元的小的互連子域組成，對每一單元假定一個(gè)合適的(較簡單的）近似解，然后推導(dǎo)求解這個(gè)域總的滿足條件(如結(jié)構(gòu)的平衡條件），從而得到問題的解。這個(gè)解不是準(zhǔn)確解，而是近似解，因?yàn)閷?shí)際問題被較簡單的問題所代替。由于大多數(shù)實(shí)際問題難以得到準(zhǔn)確解，而有限元不僅計(jì)算精度高，而且能適應(yīng)各種復(fù)雜形狀，因而成為行之有效的工程分析手段。
有限元是那些集合在一起能夠表示實(shí)際連續(xù)域的離散單元。有限元的概念早在幾個(gè)世紀(jì)前就已產(chǎn)生并得到了應(yīng)用，例如用多邊形（有限個(gè)直線單元）逼近圓來求得圓的周長，但作為一種方法而被提出，則是最近的事。有限元法最初被稱為矩陣近似方法，應(yīng)用于航空器的結(jié)構(gòu)強(qiáng)度計(jì)算，并由于其方便性、實(shí)用性和有效性而引起從事力學(xué)研究的科學(xué)家的濃厚興趣。經(jīng)過短短數(shù)十年的努力，隨著計(jì)算機(jī)技術(shù)的快速發(fā)展和普及，有限元方法迅速從結(jié)構(gòu)工程強(qiáng)度分析計(jì)算擴(kuò)展到幾乎所有的科學(xué)技術(shù)領(lǐng)域，成為一種豐富多彩、應(yīng)用廣泛并且實(shí)用高效的數(shù)值分析方法。
有限元方法與其他求解邊值問題近似方法的根本區(qū)別在于它的近似性僅限于相對小的子域中。20世紀(jì)60年代初首次提出結(jié)構(gòu)力學(xué)計(jì)算有限元概念的克拉夫（Clough）教授形象地將其描繪為：“有限元法=Rayleigh Ritz法＋分片函數(shù)”，即有限元法是Rayleigh Ritz法的一種局部化情況。不同于求解（往往是困難的）滿足整個(gè)定義域邊界條件的允許函數(shù)的Rayleigh Ritz法，有限元法將函數(shù)定義在簡單幾何形狀（如二維問題中的三角形或任意四邊形）的單元域上（分片函數(shù)），且不考慮整個(gè)定義域的復(fù)雜邊界條件，這是有限元法優(yōu)于其他近似方法的原因之一。
對于不同物理性質(zhì)和數(shù)學(xué)模型的問題，有限元求解法的基本步驟是相同的，只是具體公式推導(dǎo)和運(yùn)算求解不同。有限元求解問題的基本步驟通常為：
第一步：問題及求解域定義：根據(jù)實(shí)際問題近似確定求解域的物理性質(zhì)和幾何區(qū)域。
第二步：求解域離散化：將求解域近似為具有不同有限大小和形狀且彼此相連的有限個(gè)單元組成的離散域，習(xí)慣上稱為有限元網(wǎng)絡(luò)劃分。顯然單元越?。ňW(wǎng)絡(luò)越細(xì)）則離散域的近似程度越好，計(jì)算結(jié)果也越精確，但計(jì)算量及誤差都將增大，因此求解域的離散化是有限元法的核心技術(shù)之一。
第三步：確定狀態(tài)變量及控制方法：一個(gè)具體的物理問題通?？梢杂靡唤M包含問題狀態(tài)變量邊界條件的微分方程式表示，為適合有限元求解，通常將微分方程化為等價(jià)的泛函形式。
第四步：單元推導(dǎo)：對單元構(gòu)造一個(gè)適合的近似解，即推導(dǎo)有限單元的列式，其中包括選擇合理的單元坐標(biāo)系，建立單元試函數(shù)，以某種方法給出單元各狀態(tài)變量的離散關(guān)系，從而形成單元矩陣（結(jié)構(gòu)力學(xué)中稱剛度陣或柔度陣）。
為保證問題求解的收斂性，單元推導(dǎo)有許多原則要遵循。 對工程應(yīng)用而言，重要的是應(yīng)注意每一種單元的解題性能與約束。例如，單元形狀應(yīng)以規(guī)則為好，畸形時(shí)不僅精度低，而且有缺秩的危險(xiǎn)，將導(dǎo)致無法求解。
第五步：總裝求解：將單元總裝形成離散域的總矩陣方程（聯(lián)合方程組），反映對近似求解域的離散域的要求，即單元函數(shù)的連續(xù)性要滿足一定的連續(xù)條件?？傃b是在相鄰單元結(jié)點(diǎn)進(jìn)行，狀態(tài)變量及其導(dǎo)數(shù)（可能的話）連續(xù)性建立在結(jié)點(diǎn)處。
第六步：聯(lián)立方程組求解和結(jié)果解釋：有限元法最終導(dǎo)致聯(lián)立方程組。聯(lián)立方程組的求解可用直接法、選代法和隨機(jī)法。求解結(jié)果是單元結(jié)點(diǎn)處狀態(tài)變量的近似值。對于計(jì)算結(jié)果的質(zhì)量，將通過與設(shè)計(jì)準(zhǔn)則提供的允許值比較來評價(jià)并確定是否需要重復(fù)計(jì)算。
簡言之，有限元分析可分成三個(gè)階段，前處理、處理和后處理。前處理是建立有限元模型，完成單元網(wǎng)格劃分；后處理則是采集處理分析結(jié)果，使用戶能簡便提取信息，了解計(jì)算結(jié)果。
實(shí)踐中，有限元分析法通常由三個(gè)主要步驟組成：
1、預(yù)處理：用戶需建立物體待分析部分的模型，在此模型中，該部分的幾何形狀被分割成若干個(gè)離散的子區(qū)域——或稱為“單元”。各單元在一些稱為“結(jié)點(diǎn)”的離散點(diǎn)上相互連接。這些結(jié)點(diǎn)中有的有固定的位移，而其余的有給定的載荷。準(zhǔn)備這樣的模型可能極其耗費(fèi)時(shí)間，所以商用程序之間的相互競爭就在于：如何用最友好的圖形化界面的“預(yù)處理模塊”，來幫助用戶完成這項(xiàng)繁瑣乏味的工作。有些預(yù)處理模塊作為計(jì)算機(jī)化的畫圖和設(shè)計(jì)過程的組成部分，可在先前存在的CAD文件中覆蓋網(wǎng)格，因而可以方便地完成有限元分析。
2、分析：把預(yù)處理模塊準(zhǔn)備好的數(shù)據(jù)輸入到有限元程序中，從而構(gòu)成并求解用線性或非線性代數(shù)方程表示的系統(tǒng)。Kij*Uj=Fi式中，u 和 f 分別為各結(jié)點(diǎn)的位移和作用的外力。矩陣 K 的形式取決于求解問題的類型，本模塊將概述桁架與線彈性體應(yīng)力分析的方法。商用程序可能帶有非常大的單元庫，不同類型的單元適用于范圍廣泛的各類問題。有限元法的主要優(yōu)點(diǎn)之一就是：許多不同類型的問題都可用相同的程序來處理，區(qū)別僅在于從單元庫中指定適合于不同問題的單元類型。
3、后處理：在有限元分析的早期，用戶需仔細(xì)地研讀程序運(yùn)算后產(chǎn)生的大量數(shù)字，即列出的模型內(nèi)各離散位置處的位移和應(yīng)力。這種方法容易漏掉重要的趨向與熱點(diǎn)，而最新的程序則利用圖形顯示來幫助用戶直接觀察運(yùn)算結(jié)果。典型的后處理模塊能顯示遍布于模型上的彩色等應(yīng)力線圖，以表示不同的應(yīng)力水平，顯示的整個(gè)應(yīng)力場的圖像類似于光彈性法或云紋法的實(shí)驗(yàn)結(jié)果。
附錄2：外文原文
出處：Finite element overview
There are many types of CAE technology, including the finite element method, boundary element method, finite difference method. Each method has its own application areas, of which the application of finite element method more and more areas, has been used in structural mechanics, structural dynamics, thermodynamics, fluid mechanics, circuit theory, electromagnetism and so on.
??? ANSYS software is the financial structure, fluid, electric field, magnetic field, acoustic field analysis in one large-scale finite element analysis software. By the world's largest finite element analysis software ANSYS, one of the United States developed it with most CAD software interface for data sharing and exchange, such as Pro / Engineer, NASTRAN, Alogor, I-DEAS, AutoCAD, are modern Advanced CAE product design tools.
??? ANSYS finite element package is a multi-purpose finite element method for computer design program, can be used to solve the structure, fluid, electricity, electromagnetic fields and collision issues. So it can be applied to the following industries: aerospace, automotive, biomedical, bridges, construction, electronics, heavy machinery, micro-electromechanical systems, sports equipment, etc..
Finite Element Analysis (FEA， Finite Element Analysis) of the basic concept is to re-place the relatively simple problem to solve complex problems later. As it will solve the do-main is composed of many small-called finite element subdomain interconnection compone-nts，assuming that each unit of an appropriate (relatively simple) approximate solution， and then derived the general solution of the domain satisfy the conditions (such as balanced con-ditions)， thus the solution of the problem. This solution is not exact solutions，but appro-ximate solution， since the actual problem is relatively simple to replace the problem. Since most practical problems it is difficult to be accurate solution， while finite element is not only high accuracy but also to adapt to a variety of complex shapes， thereby becoming an effective means of engineering analysis.
???? FEM together those who are able to express the actual domain for the discrete element. The concept of the finite element as early as several centuries ago and have been applied， for example， polygon (a finite number of straight-line unit) to get close to circle the cir-cumference of a circle， but as a way to be made， it is the most recent matter. Finite ele-ment method was originally known as the matrix approximation method， the structural strength of aircraft used in the calculation， and because of its convenience， practicality and effectiveness arising from research scientists to engage in mechanical interest. Through the efforts of just a few decades， with the rapid development of computer technology and the popularity of the finite element method in structural engineering from the intensity of the rapid analysis extended to almost all areas of science and technology， become a rich and colorful， practical and efficient application of a wide range of numerical analysis.
???? Finite element method with other methods of solving the boundary value problem simil-ar to the fundamental difference is that the approximation of it is limited to relatively small sub-domain. 60 In the early 20th century structure was first proposed the concept of the finite element calculation of Clough (Clough)， Professor vividly describes as: "The finite element method + = Rayleigh Ritz method piecewise function"， that is， the finite element method is the Rayleigh Ritz method a localized situation. Different from the solution of (often difficult) to satisfy the boundary conditions of the definition of domain function to allow the Rayleigh Ritz method， finite element method will be defined in a simple function of geometry (such as two-dimensional problem of arbitrary quadrilateral or triangle) on the unit domain ( piecewise function)， the definition does not consider the whole domain of the complex boundary conditions， this is the finite element method is superior to other similar methods of one of the reasons why.
???? Different physical properties and mathematical models of the problem， finite element method to solve the basic steps are the same， only the specific formula to solve a different derivation and computation. Finite Element Analysis of the basic steps are as follows:
???? The first step: the definition of the problem and solution domain: In accordance with the actual problem solving domain approximation to determine the physical properties and geometry of the region.
???? The second step: Solving domain discretization: The approximate solution of the domain with different size and shape of a limited and linked to each other unit， composed of a fin-ite number of discrete domains， the habit of division as the finite element network. Obvio-usly the smaller the unit (the finer t he network) is similar to the level of discrete domain， the better，the more accurate results， but the calculation of the volume and error will be larger，so to solve the discrete domain is the finite element method，one of the core tech-nology.
???? The third step: to determine the state variables and control method: a specific physical problem can usually be handled by a group of state variables include the issue of boundary conditions that the differential equations for the finite element for solving differential equa-tions are usually translated into the functional equivalent forms of .
???? Step four: unit derived: on the unit to construct a suitable approximate solution， that is derived out of the finite element type， including a reasonable choice of coordinate system units， the establishment of unit test function， to one way or another unit of the state va-riables given the discrete relations to form the unit matrix (the structure of said mechani-cal stiffness or flexibility matrix array).
???? In order to ensure the convergence of problem solving， there are many principles de-rived units to follow. In terms of engineering applications， it is important to pay atten-tion to each unit of problem-solving performance and constraints. For example， the unit should be based on the rules for shape， and deformed not only low-precision， but also the risk of missing rank， will result in failure to solve.
???? Step five: Solution assembly: assembly to form a discrete unit of the total domain matrix equation (Joint equations)， reflecting the approximate solution of the discrete domain the request domain， that is， the continuity of function modules to meet the conditions for cer-tain. Assembly unit in the adjacent node， the state variables and their derivatives (if possib-le) to establish continuity in the junction point.
???? Sixth step: solving simultaneous equations and the results of the interpretation: the finite element method eventually lead to simultaneous equations. Simultaneous equations can be used to solve the direct method， the election law and the random generation method. Solv-ing a result， the state Department unit node approximation variables. The results for the quality and design guidelines will be provided to allow values to evaluate and determine the need for double-counting.
???? In short， the finite element analysis can be divided into three stages， pre-treatment， processing and post-processing. Pre-processing finite element model is built to complete the unit mesh; post-processing is the acquisition and processing the results of the analysis， a-lows users to extract information easy to understand results.
???? In practice， the finite element method is usually composed of three main steps:
???? 1， pre-processing: the user object to be analyzed to establish part of the model， in this model， the geometry of the part being cut into several discrete sub-region - otherwise known as "modules." In some of the modules referred to as "nodes" of the discrete points connected with each other. Some of these nodes are fixed displacement， while the remaining loads are given. Prepare such a model could be extremely time-consuming process is why the commercial competition between the lies: how to use the most friendly graphical inter-face of the "pre-processing module"， to help users complete the tedious work of boring. Some pre-processing module as a computerized drawing and an integral part of the de-ign process， can be pre-existing CAD file grid coverage， which can be easily completed by Finite Element Analysis.
???? 2， Analysis: the pre-processing module prepared data into finite element program,and thus constitutes a solution of linear or nonlinear system of algebraic equations that
Kij * Uj = Fi
??? Where u and f，respectively，for each node of the displacement and the role of external forces. Matrix form of K depend on the type of problem solving， the module will outline the truss with the linear elastic stress analysis. Business procedures may carry a very large library， the different types of unit s applicable to a wide range of various problems. Finite element method is one of the main advantages of: Many different types of problems are available to deal with the same procedure， the difference is only specified from the cell library for the problem in different cell types.
???? 3， post-processing: In the early finite element analysis， users need to carefully study the procedures for computing a large number of figures after， that is， the model set out in the discrete position of the displacement and stress. This method is easy to miss important trends and hot spots， and the latest graphics processing to be use to help the user com-puting the results of direct observation. Typical post-processing module can display the model across the color line graph of stress for different stress levels， indicating the entire stress field is similar to the images or Photoelasticity moire results.
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