车辆工程毕业设计40基于有限元分析的汽车车架优化设计

I摘要车架是汽车上重要的承载部件，车辆所受到的各种载荷最终都传递给车架，因此，车架结构性能的好坏直接关系到整车设计的成败。通过有限元法对车架结构进行性能分析，在设计时考虑车架结构的优化，对提高整车的各种性能，降低设计与制造成本，增强市场竞争力等都具有十分重要的意义。大型通用有限元软件ANSYS凭借其强大的分析功能和高度可靠性，在结构静力分析和动力分析以及优化设计等方面具有无可比拟的优越性。本文以CA1040货车车架结构为研究对象，通过对Pro／E和ANSYS软件的消化与吸收，采用实体单元，对车架结构的有限元建模、车架结构的静、动态特性分析问题进行了研究。以实体单元为基础创建了车架结构的简单的尺寸优化模型，以车架的纵梁截面尺寸为设计变量，以车架结构的总体积最小为优化目标，对车架纵梁的截面尺寸进行优化并分析了优化结果。阐述了应用ANSYS进行结构优化设计的基本指导思想及方法，推广到解决以板壳单元为基础的车架优化问题，根据实际需要调整优化的设计变量、状态变量以及目标函数。通过对CA1040型货车车架结构的有限元仿真及优化，得到了一些有益的结论，为车架的设计提供了指导作用。关键词：车架；载荷；轻量化；有限元分析；三维建模；ANSYSIIABSTRACTFrameisasanimportantassemblybearingloadsofanautomobile，whichallkindsof10adswillpassto，andasaresulttheperformanceofframestructureaffectswhethertheautomobiledesignissuccessfulornot．Usingfiniteelementmethodtoanalyzeautomobileframestructureandtotakeframestructureoptimizationintoaccountmakessenseinimprovingautomobileperformance，reducingthecostofdesignandautomotivemanufactureandincreasingcapabilityofmarketcompetition．ANSYSsoftwaretakesonunexampledadvantagesinstaticanalysis，dynamicanalysisandoptimizationdesignetcbyrightofitspowerfulanalysisfunctionandhighreliability．ThroughstudyingPro／EandANSYSsoftwaretheFEAmodelofaCA1040truckwithsolidelementsWasbuilt．Basedonthemodelthestaticanddynamicperformanceofthetruck’Sframestructurewasstudied．Atopologicaloptimizationmodelandasimpleoptimizationmodelwasbuiltbasedonsolidelements．Withtheobjectionthatthevolumeoftheframeisminimal，thecarlingsectiondimensionswasoptimizedandtheresultsofoptimizationWasanalyzed．Thispaperanalyzestheprinciplesandmethodsofoptimizationdesign，whichCanbegeneralizedtoshellelementmodel．Thedesignvariables，stateVadablesandobjectivefunctionscanbeadjustedtomeettheactualneeds．ThroughthefiniteelementsimulationandoptimizationofaCA1040truckframestructuresomeusefulconclusionshasbeengotforthedesignoftheframe．Keywords：Frame;loads;Lightweight;Finiteelementanalysis;Three-dimensionalmodeling;ANSYS目录摘要······································································································IAbstract·······························································································II第1章绪论·························································································11.1研究目的和意义···········································································11.2研究背景····················································································11.3有限元法在国内外车架结构设计中的研究现状····································21.4主要研究内容及技术路线·······························································4第2章有限元结构的基础理论·····························································62.1有限元法的基本理论·····································································62.1.1有限元法的基本概念·····························································62.1.2有限元法的基本思路·····························································62.2ANSYS软件的简介·········································································72.2.1ANSYS的主要特点·································································72.2.2ANSYS的主要功能·································································82.2.3ANSYS的结构分析文件···························································92.2.4ANSYS提供的分析类型···························································92.3本章小结···················································································10第3章车架有限元模型的建立····························································123.1模型的建立原则··········································································123.1.1几何建模的注意事项····························································123.1.2几何建模的简化··································································133.2建立车架模型·············································································143.2.1建模时的简化处理·······························································143.2.2车架模型的建立··································································143.2.3应用ANSYS对车架模型进行网格划分·······································143.2.4对实体单元Sold92的简要介绍·············································153.3本章小结···················································································16第4章车架结构的有限元静态分析·····················································174.1车辆载荷分析·············································································174.1.1行驶载荷···········································································174.1.2操作载荷···········································································174.1.3特殊载荷···········································································184.2车架受力情况·············································································184.2.1静载荷··············································································184.2.2动载荷··············································································194.3车架结构的静力性能分析······························································194.3.1静力分析的基本概念及流程···················································194.3.2车架结构静力分析工况及约束处理··········································204.3.3车架结构静力分