内燃机微动疲劳损伤的试验与仿真研究

本文针对内燃机机体隔板与主轴承盖螺栓紧固连接处的微动疲劳问题展开研究工作。通过对主轴承盖所受载荷模式的分析,设计了内燃机微动疲劳实验系统及相关实验方法,进行了内燃机典型紧固结构微动疲劳等效模型实验。结合对螺栓连接紧固面接触应力场分布的有限元分析结果,研究了主轴承盖与机体隔板紧固面微动疲劳失效机理。研究表明,螺栓预紧力和主轴承盖所承受的附加扭转力矩是影响机体隔板与主轴承盖紧固连接微动疲劳的主要因素,附加翻转力矩的波动使接触区的接触状态不断变化,导致接触区表面的损伤；通过增加螺栓预紧力有助于减缓机体隔板与主轴承盖紧固连接的微动疲劳损伤。

Numerical and Experimental Study on Fretting Fatigue Damage of IC Engine

This paper investigates the fretting fatigue problems of the bearing cap bolted joints of the IC engine. A fretting fatigue test system and experimental method was designed by analyze the load pattern of the main bearing cap of the IC engine. Correspondingly, a series of test was carried out. The fretting fatigue damage mechanism was discussed depending on the fretting fatigue test results and the FEM analysis of the bearing cap bolted joints of the IC engine. The result shows that the bolted pretention load and the additional torque of the main bearing cap are the two main factors which influence the fretting fatigue behavior of the bearing cap bolted joints of the IC engine. The fluctuation of the additional torque make the contact status changed time by time, resulting the damage of the contact interface; increasing the bolted pretention load will relieve the fretting fatigue damage of the bearing cap bolted joints of the IC engine.