毕业设计（论文）-汽车排气系统结构设计.docx

Ⅰ 汽车排气系统结构设计 摘要 汽车排气系统是汽车的重要组成部分，是影响NVH的重要因素之一。一个合格的发动机排气系统可以使排出的废气污染和噪声减小，实现汽车燃油经济性，动力性等重要性能。 本文以某汽车的排气系统为研究对象，首先查阅了大量资料，了解了海内外一些学者相关设计和研究现状，并选取了一些结构参数例如：悬置刚度参数以及波纹管参数等等；之后利用CATIA三维设计软件完成排气系统的三维实体模型的基本设计；然后以Hypermesh为辅助工具建立了排气系统、主消声器以及挂钩的网格模型，之后对整个排气系统进行模态分析。 然后，基于上述模态分析结果，比较该排气系统的优劣之处，之后针对主消声器进行优化。同时比较了优化前后的具体差异，并且绘制出了模态分析图等。 最后对挂钩和主消声器等零部件进行了仿真分析，可以看到优化之后挂钩和主消声器的振动能和振动峰值有显著的降低。 关键词：挂钩应力分析，汽车排气系统，模态分析 全套图纸加扣 3346389411或3012250582 Ⅱ Abstract Automobile?exhaust?system?is?an?important?component?of?automobile?and?one?of?the?important?factors?affecting?NVH.?A?qualified?engine?exhaust?system?requires?us?to?carry?out?repeated?research?and?design,?which?is?also?the?only?way?to?achieve?the?vehicle?fuel?economy,?power?performance?and?other?important?performance. Taking?the?exhaust?system?of?a?certain?automobile?as?the?research?object,?this?paper?first?consulted?a?large?number?of?materials,?learned?about?the?design?and?research?process?of?some?scholars?at?home?and?abroad,?and?selected?some?basic?parameters?based?on?the?knowledge,?common?sense?and?some?necessary?skills?accumulated?and?learned?in?the?four?years?of?undergraduate?study,?as?well?as?the?help?of?seniors?and?mentors.?For?example:?suspension?stiffness?parameters?and?bellows?parameters?and?so?on.?After?the?basic?work?is?completed,?the?basic?design?of?the?3d?model?is?completed?with?the?help?of?the?tutor.?Then?the?main?muffler?of?the?exhaust?system?was?built?with?HyperMesh?as?an?auxiliary?tool.?Then?it?is?modal?analyzed,?and?then?the?results?are?analyzed?and?integrated,?and?then?the?whole?exhaust?system?is?modal?analyzed. After?the?game?analysis,?I?started?to?optimize?the?system,?mainly?the?hook?and?the?main?muffler.?At?the?same?time,?the?concrete?differences?before?and?after?optimization?are?compared,?and?the?stress?analysis?cloud?map?is?drawn. Finally,?the?static?stress?and?vibration?of?the?hook?and?the?main?muffler?are?analyzed,?and?it?can?be?seen?that?the?vibration?energy?and?peak?vibration?of?the?hook?and?the?ma