Abstract: In this paper the finite element model of the exhaust system of a vehicle is established for modal analysis simulation, the natural frequencies and modal shapes of first several orders are obtained . Based on modal analysis and the results of vibration test of the exhaust system , vibration characteristics of the exhaust system at different engine speed are analyzed and the suggestions to improve the structure are given for reference to enhance operational reliability and service life of the exhaust system.

Key words: vibration and wave , vehicle exhaust system , finite element model；modal analysis , vibration analysis

摘要： 建立某汽车排气系统的有限元模型，对其进行模态分析仿真，得到排气系统的前若干阶的固有频率及其振型。基于模态分析和排气系统的振动测试结果，对排气系统在发动机不同转速下的激励引起的振动进行分析，研究排气系统的振动特性，提出结构的改进意见，为提高排气系统的工作可靠性和使用寿命提供参考。

关键词: 振动与波, 汽车排气系统, 有限元模型, 模态分析, 振动分析