基于有限元的内燃机曲轴疲劳强度分析

摘要

内燃机曲轴轴颈的过渡圆角处是应力高度集中部位，是疲劳裂纹的最先形成位置，因此曲轴圆角是曲轴设计时需要重点关注的部位：，文章采用NASTRAN软件对某发动机缸体进行模态缩减，利用EXCITE—PU软件进行动力学分析，再通过N-son软件进行圆角的疲劳安全系数分析。结果表明，通过增加圆角半径的方式可以解决曲轴的断裂问题，%In an internal combustion engine, the transition fillet of crankshaft-necks easily creates stress concentration. It is also the place that brings fatigue, fillet of crankshaft is key problem when designing the crankshaft. In this paper, modal condense had been performed on a certain engine by using NASTRAN. And dynamic analysis had been done by using EXCITE-PU. At last, fatigue safety factor of fillet had been performed by using N-soft. The resuh shows that the problem of broken crankshaft can be solved by increasing the crankshaft fillet.