王宝军1,2，孙晶晶1,2，李连升1,2，马庆镇1,2，李德华1,2，侯晓良1,2
1.内燃机可靠性国家重点实验室，山东潍坊261061;2.潍柴动力股份有限公司发动机研究院，山东潍坊261061
摘要：针对发动机排气管出现的裂纹问题，基于热机耦合方法，采用Abaqus软件对故障排气管进行温度场和应力场分析。结果表明：排气管区域应力较大，应力最大的区域与裂纹故障部位相吻合。基于分析结果对故障部位进行优化，将排气管结构由铸造单筋改为管体两侧铸造双筋。对优化方案进行仿真分析，结果表明优化后排气管所受最大应力比改进前降低了87 MPa。发动机装配优化后排气管进行3000 h耐久试验，无开裂故障发生。
关键词：排气管；裂纹；热应力；筋
Abstract:In order to solve the crack problem of engine exhaust pipe, the thermalmechanical coupling method is used to analyze the temperature and stress field of the engine exhaust pipe. The results show that the stress of the exhaust pipe is large and the region with the maximum stress value is consistent with the failure position in the test. The structure of exhaust pipe is then changed from casting single rib to casting double rib on both sides of the pipe body, and it is simulated and verified by test. The results show that the maximum stress of the optimized exhaust pipe is reduced by 87 MPa, and no cracking failure occurred in the 3000 h endurance test.
Keywords:exhaust pipe; crack; thermal stress; rib
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