车身接附点FREE-FREE静刚度分析规范

Q/SZJ191001-2017车身接附点FREE-FREE静刚度分析SpecificationofFree-FreeStaticStiffnessAnalysisatBodytoChassis,PowertrainAttachmentPoints20XX20XX-06-30实施20XX-05-29发布XXXX汽车工程技术有限公司发布Q/SZXX-X-2017车身接附点FREE-FREE静刚度分析范围本标准规定了术语和定义、车身接附点FREE-FREE静刚度分析方法及结果处理方法。本标准适用于CAE部门车身接附点FREE-FREE静刚度分析。规范性引用文件无。术语和定义无。摘要Abstract本文档旨在说明车身与底盘的安装接附点的X,Y,Z三个方向的静刚度计算的仿真分析过程。ThisdocumentdescribesacommonprocedureforthestaticstiffnessanalyticalsimulationalongX,Y,Zdirectionsofattachedpointsbetweenbodyandchassis,powertrainsystems.流程图ProcessFlowDiagram建模建模BuildFEmodel设置边界条件Defineconstraints/boundaryconditions设置加载条件Defineloads计算SubmittoNastranorOptistruct处理输出文件Dealwiththeoutputfiletogettheresults结果是否满足要求Istheresultsok?整备车身CAD模型TrimmedBodyCADmodel结束EndYES优化OptimizationNO图1流程图Fig1ProcessFlowDiagram工具描述ToolDescription仿真分析过程中需要用到的如下软件:Thefollowingsoftwarefacilitatestheanalyticalsimulationprocess:前处理(Preprocessors):Hypermesh求解器(AnalysisCode):MSC.NastranorOptistruct后处理(Postprocessors):Hyperview建模和分析过程Modeling/AnalysisProcedure单位Units分析中所用单位制如下所示:Theunitsusedintheanalysisareasfollows:力(Force) 牛顿(N)质量(Mass) 吨(Ton)长度(Length) 毫米(mm)时间(Time) 秒(Second)内容Contents分析模型为TrimmedBody，具体的建模细则参考TrimmedBody的建模规范，如图2。Themodelcontainstrimmedbody,andthemodelbuildingdetailscanrefertoTrimmedBodyModelingguidelines,asshowninFigure2.图2TrimmedBody模型Figure2TrimmedBodyModel坐标系CoordinateSystems全局坐标系Thestandardglobalcoordinatesystem.建模技巧ModelingTechniques网格质量要求，平均单元尺寸3-8mm，翘曲小于12°，雅克比大于0.6，三角形单元数量小于10%。局部应力区域没有三角形单元，关键安装点周围没有三角形单元。增加一圈washer在螺栓孔上。螺栓用Rbe2+Cbar单元或Rbe2+Rbe2单元模拟。焊缝用Penta焊缝类型模拟。简化结构用Rbe3+Mass模拟。Meshqualityrequirements:Averageelementsizeis3to8mm,Warpage<12,Jacobin>0.6，Triangleselementproportion<10%.Notrianglesinlocalstressconcentratedarea.Notriangularelementsaroundkeyfixpoints.Addonewasherattheboltholes.UseRbe2+CbarelementsorRbe2+Rbe2elementstosimulatebolts.UsePenta-typedweldtosimulatewelds.Rbe3+Masselementisusedtomodelsimplifiedparts.假设和限制Assumptions/Limitations假设Assumptions与物理试验相比较，对于焊点焊缝失效和材料局部撕裂的地方，分析模型假设没有焊点焊缝失效和材料撕裂。对于螺纹连接处，假设分析模型没有螺纹失效。Assumptions:Incomparisonwiththephysicaltest,wherespotweldsmailfailandmaterialmaylocallytear,theanalyticalmodelassumesnoweldsfailureandnomaterialtear.Astothescrewingconnection,theanalyticalmodelassumesnoscrewingfailure.限制ConstraintsN/A.载荷和边界条件Loads/BoundaryConditions约束和边界条件Constraints/BoundaryConditions无约束条件。求解器NASTRAN中采用惯性释放，使用参数param,inrel,-2.NoSPCconstraintsinthemodel.UsetheinertiareliefinNASTRAN,withparam,inrel,-2card.载荷Loads在各接附点分别作用沿X、Y和Z向的单位力。如图3所示，为车身与前副车架的左侧接附点，分别作用沿X、Y和Z向的单位力。ApplyunitloadsattheattachmentpointsinX,YandZdirectionsontheseparatesubcases.UnitloadsappliedattheleftattachmentpointbetweenfrontsubframeandbodyinX,YandZdirectionsisshowedinFigure3.图3沿X、Y和Z向的单位力载荷Fig3UnitloadsintheX,YandZdirection结果Results结果格式ResultsFormats输出各工况加载点对应的X、Y或Z方向的位移，其静刚度为位移的倒数。OutputdisplacementsatalltheloadingpointsinX,YandZdirections.Stiffnessisreciprocalofdisplacementateachpointoncorrespondingsubcases.相关测试CorrelationTestsN/A性能要求PerformanceRequirements接附点的刚度要求与项目相关，应参考该项目的《整车CAE性能目标与方案》所设定的目标。Stiffnessatattachmentpointsisprogramspecific,whichreferstoprogram《整车CAE性能目标与方案》fortargets.分析要求AnalysisRequirements时间历程结点TimeHistoryNodesN/A输出文件OutputFiles输出文件为op2文件或H3D文件，用以记