1.宁波吉利罗佑发动机零部件有限公司，浙江 宁波 315336；2.浙江大学工程师学院，浙江 杭州 310058
Abstract：In order to solve the cracking fault of the hot end support of the exhaust system during the durability development of a engine, the method of combining fluid-structure coupling and low cycle fatigue analysis is used. It is found that under the condition of alternating cold and heat, the turbocharger volute expands and contracts repeatedly, and constantly pulls and squeezes the supercharger support. Thus the thermal strain is concentrated and accumulated until it reaches the low cycle fatigue life limit and cracks appear. The optimization is carried out to reduce the temperature gradient and uniform stiffness transition of the support at the crack. After optimization, the equivalent plastic strain of the support corresponding to the original crack is reduced to 0.001, the thermal strain is eliminated, and finally verified by the durability test.
Keywords:hot end bracket; crack; low cycle fatigue; plastic strain