温度场分布下汽车排气系统振动疲劳寿命分析  

RESEARCH ON VIBRATION FATIGUE LIFE OF VEHICLE EXHAUST SYSTEM UNDER TEMPERATURE FIELD DISTRIBUTION

作　　者：舒爱梅 翁建生[1] 韩强[2] 余文杰[2] 孙鹏飞 李继伟 SHU AiMei;WENG JianSheng;HAN Qiang;YU WenJie;SUN PengFei;LI JiWei(College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Suzhou Automotive Research Institute of Tsinghua University,Suzhou 215134,China)

机构地区：[1]南京航空航天大学能源与动力学院,南京210016 [2]清华大学苏州汽车研究院,苏州215134

出　　处：《机械强度》2020年第3期667-674,共8页Journal of Mechanical Strength

基　　金：国家自然科学基金项目(51775269);江西省汽车噪声与振动重点实验室2018年度开放基金(JXNVHKB-KFKT-201801)资助。

摘　　要：为了研究温度场分布对排气系统振动固有特性与振动疲劳寿命的影响,应用试验和双向流固耦合等数值计算方法分析排气系统固体温度场分布,研究温度场分布对排气系统热模态影响,并采用频域振动疲劳寿命Dirlik估计法对某国六排气系统在温度场分布下的振动疲劳寿命进行分析估算。结果表明,在温度场作用下结构模态频率降低,并且考虑温度分布的疲劳寿命相对室温振动疲劳寿命降低90.8%。因此温度场分布对排气系统的振动固有特性和疲劳寿命影响显著,在产品开发阶段不可忽视。Aiming at analyzing the influence of thermal load and mechanical load on the vibration characteristics and fatigue life of the exhaust system,the finite element model and modal test were conducted by modal analysis.The temperature field distribution of the exhaust system was obtained via CFD analysis.Finally,a frequency-domain called Dirlik was applied to analyze the vibration thermal fatigue life of this exhaust system.The results show that the structural modal frequency decreases under the temperature field distribution,and the fatigue life of the exhaust system considering temperature field distribution is 90.8%lower than that not considering temperature distribution.Therefore,the temperature field distribution has significant effects on the fatigue life of the exhaust system,and it can’t be ignored during the development process.

关 键 词：排气系统 振动疲劳 流固耦合 模态分析 温度场分布 振动固有特性 

分 类 号：TH114[机械工程—机械设计及理论]