摘要
为解决排气歧管隔热罩在发动机台架耐久试验中开裂的问题,对隔热罩进行了FEA分析,包括模态分析和动响应分析。结果显示其一阶模态低于发动机最高点火频率,最大振动响应力超过设计要求,位置与实际开裂位置相吻合,开裂根本原因为共振导致应力过大。根据分析结果对隔热罩进行优化改进,新方案隔热罩模态得到提高,振动响应力下降,满足设计要求,并通过了台架耐久试验考核,验证了优化改进方案的可靠性。
In order to solve the crack issue of exhaust manifold heat shield in the engine bench durability test, the FEA analysis including modal analysis and dynamic response analysis is carried out. The results show that the 1 st frequency is lower than the max engine ignition frequency, the maximum stress is higher than the requirements, and the position of the max stress is the same as the actual crack. The root cause of the crack is the too high stress because of the resonance. Based on the results, the heat shield is optimized, including changing the rib, adding another mounting, changing the mounting position and the bolts. After optimization, the model is improved and the maximum response stress is reduced, which can meet the requirements. The new proposal is validated in the engine bench durability test.
出处
《上海汽车》
2018年第10期40-43,共4页
Shanghai Auto
