基于热机械疲劳分析的排气歧管优化设计  

The optimization design of exhaust manifold based on thermo mechanical fatigue analysis

作　　者：张雪林[1] 路明[1] 朱凌云[1] 王军[1] 

机构地区：[1]安徽江淮汽车股份有限公司技术中心,安徽合肥230601

出　　处：《机械》2015年第2期33-35,55,共4页Machinery

摘　　要：联合AVL-Fire和ABAQUS软件,对某直喷汽油机进行排气歧管热机械疲劳分析。首先利用AVL-Fire软件得到排气歧管在全速全负荷工况、倒拖工况和怠速工况下的内外表面热边界条件,映射到有限元单元上进行耦合计算,得到相应工况下的温度场以及应力场分布,并通过热机械循环计算排气歧管的累积塑性应变,判断排气歧管是否会发生低周疲劳断裂,并根据分析结果对排气歧管进行优化设计。结果表明此方法可以很好的应用在排气歧管优化设计上。Combined with AVL-Fire and ABAQUS software, the thermo mechanical fatigue evaluation had been performed for the exhaust manifold of a direct injection gasoline engine. The thermal boundary conditions of the exhaust manifold＇s inner surface was got by using AVL-Fire software in full load, motored and low idle thermal loads. By mapping the thermal boundary conditions to the finite element, and coupling with the solid element of the exhaust manifold, the temperature and stress field were obtained. The total accumulated plastic strain was calculated through the thermo mechanical cycle to judge whether the low cycle fatigue fracture being occurred. And according to the results of the analysis the optimization design of exhaust manifold was carried out. The results showed that this method could be well applied in the exhaust manifold optimization design.

关 键 词：排气歧管 耦合 热机械疲劳 塑性应变 

分 类 号：U464.134.4[机械工程—车辆工程]