李义，杨晶，刘永进

山河智能装备股份有限公司国家企业技术中心，湖南 长沙 410100

摘要：以某车用发动机机体为研究对象，利用有限元分析软件建立机体三维模型，采用转矩-转角法过屈服条件计算机体内各零部件的应力分布与接触正应力，利用增广型拉格朗日法仿真分析不同螺栓的接触应力，并在专用拧紧机上对机体主轴承盖螺栓进行拧紧试验。结果表明：M10×1.5-10.9螺栓在屈服拧紧条件下，机体零部件各部位未出现任何失效，符合发动机对螺栓性能的需求；M10×1.5-12.9螺栓在屈服拧紧条件下，主轴承盖一侧出现轻微压溃现象，需要对机体相关零部件进行结构或者材料优化才能满足发动机要求；仿真分析与经验计算和试验结果基本一致。该分析方法可为发动机机体零部件结构和材料优化提供参考。

关键词：机体；螺栓；轴向力；有限元分析；接触应力；拧紧试验

Abstract：A vehicle engine block model is established by using the finite element analysis software, the stress distribution and contact normal stress of various parts in the body are calculated by using the torque angle method over yield condition, the contact stress of bolts is simulated by using the augmented Lagrange method, and the tightening test of the main bearing cap bolt of the block is carried out on a special tightening machine. The results show that under the condition of yield tightening of M10×1.5-10.9 bolts, there is no failure in all parts of the engine body, which meets the requirements of the engine for bolts. Under the condition of yield tightening of M10×1.5-12.9 bolts, there is a slight crushing phenomenon on one side of the main bearing cap. It is necessary to optimize the structure or materials of relevant parts of the engine block. The simulation analysis is basically consistent with the empirical calculation and test results. The analysis method can provide a reference for the structural and material optimization of engine block parts.

Keywords:body; bolt;axial force; finite element analysis;contact stress; tightening test