文档介绍：华中科技大学硕士学位论文重型自卸车车架的有限元分析及其早期断裂原因分析姓名:尹辉俊申请学位级别:硕士专业:机械电子工程指导教师:彭芳瑜 20061025 华中科技大学硕士学位论文摘要某汽车公司的重型自卸车在产品的开发、试验和用户的使用过程均发现有车架结构的早期断裂问题,主要位于车架折弯的变宽度的地方。为此,从理论和有限元分析、电测实验着手,研究车架出现应力集中的地方,找出了车架早期断裂的原因, 通过减小或消除该处的应力集中来解决早期断裂问题,并提出改进方案。本文建立了以壳单元为基本单元的车架有限元计算模型,在此模型的基础上首先进行车架静强度分析和静态电测实验,得到车架在典型工况下的应力分布情况: 其次对车架做模态分析,得到车架的各阶段固有频率和固有振型;最后做动态电测实验,得到车架在典型路面激励下的位移响应和应力响应。根据有限元分析结果和电测实验结果,分析出车架过早断裂的原因,提出改进方案,并对改进后的车架进行12000公里的坏路面的可靠性实验以验证改进方案。本文对该型自卸车车架的有限元分析方法和过程,适用于各类车架的设计与分析。关键词:车架有限元法模态分析自卸车断裂疲劳华中科技大学硕士学位论文 Abstract The early fractures orfailures ale usually located atthechangeable width offolding positions of the frame structBl'e fortheproducts of heavy dump truck during the development,testing and operation of the thesis focus on analyzing locatiOIlSof stress concentration,and causes of failure or early fracture ofthe franle structure based ontheoretical orfinite element analysis,as well asinstrumentation testing; proposing improvement ofthe flame structure byreducing or eliminating the effects of stressconcentration tosolve theproblems. Inthethesis,the shellelement isused insetting up acomputational modeling of finite element analysis forthe fl',the staticanalysis andinstrumentation testing were implemented based on themodeling toobtainthedistributions ofsnesses and deformations oftheflamestructure;second,modal analysis was implemented toobtain natural frequencies and shapes oftheframe structure ofdifferentseries;third,dynamic instrumentation testingWasconducted to obtaindisplacement and stressresponses;finally, the c,aasesfor early fracture of flame structure of the trailerWas analyzed and improvement oftheflame structureWasproposed andimplemented based on results of finiteelement analysisand 12000 km poor roadtesting or reliabilitytesting fortheimproved fl锄lle structure Wasimplemented toverify effectofthe fl'anle-structureimprovemenL Themethod,procedures end resultsoffiniteelement analysis forthe frame stru