文档介绍：硕士学位论文轻型客车车身有限元建模与动态仿真摘要汽车车身的结构振动是一个工程中的经典问题。本文应用有限元仿真与试验相结合的手段来尝试研究发动杌不同转速下车身结构的振动特性。本次研究以某种轻型客车的白车身为对象,分析了车身的结构特征, 提出了有限元动态分析模型的建模方法与简化原则。针对该型轻型客车具有坚固的蒙皮的特点,完全采用三维曲面建立了蒙皮与车梁相结合的白车身整体模型,并灵活运用混合分网的方法进行了单元划分,良好地解决了计算精度与计算成本之间的矛盾。继而分别进行了车身的有限元模态计算与实车车身的模态试验,通过对二者得到的振型和固有频率之间的对比, 检验了该车身有限元模型的可靠性。在此基础上,针对该型车发动机引起的激振力主要来自二阶惯性不平衡力矩与燃烧爆发力的机理,进行了相应频带内的车身谐波响应分析。以发动机悬架中间支承处为激励点,计算了布置在车身表面的14个点在发动机整个转速范围内的位移响应,并分别计算了车身在怠速、发动机最大输出转矩、发动机额定转速等几个常用转速下二阶不平衡力导致车身板件振动的响应,找到了发动机工作时车身板件中可能产生强烈振动的部分,为有效地减小因此产生的车身结构振动与噪声奠定了基础。关键词:有限元法,车身,模态分析,结构振动,仿真硕士学位论文轻型客车车身有限元建模与动态仿真 Abstract The study on structuralvibration character ofvehicle’Sbody is aclassicproblem inthe engineering paper studed thebody structural vibration parameters under different rotate speeds ofthe engine wim themethod integrating finiteelement simulation with experiment. Inthispaper,the structural characteristics of akindoflight bus body was detailedly analyzed and themodeling and simplification phnciples fordynamic analysis were brought thebushassolidpanels,a finiteelementmodel of thewhite body Wagbuiltby merging thepanelsand beams ofthebody which had pletely modeled by surfaces. The model was meshed by themixed meshing method and thecontradiction between the themodalofthebody Wasrespectively gotten through finiteelement andexperiment method,themodes and naturalfrequency results pared。The resultshowed that thebody’S finiteelementmodelWas this base,since the exciting forces weremainly origin from theengine’s second order inertia unbalance moment bustion force,the harmonic response tothebody Wasanlyzed. Inthisprocess,The point atthebearing ofthe engine‘s suspension was selected as the prompted place and thedisplacement responses offourteenpoints on thebody surface were calculated during allthe rotate speeds the body panels’vibration responses totheengine’S second order inertiaunbalance moment and eonbustion forcewere cal