某连杆强度和疲劳有限元优化分析计算

Finite Element Optimization Analysis and Calculation of Strength and Fatigue of a Connecting Rod

连杆作为内燃机的重要零部件之一,受到交变的拉伸负荷和压缩负荷的作用,可能会导致连杆螺栓、大头盖或者连杆杆身的断裂等。针对该种情况,本文通过有限元方法进行仿真分析,对极限工况下的应力分布和疲劳强度进行了计算分析。计算结果表明,该型连杆用料偏多,在强度上过于安全。因此,本文在计算结果的基础上,根据对连杆设计的轻量化需求,对连杆几何结构进行了优化,使得连杆体积较少了9.54%。优化后的连杆虽然安全系数略小于原模型,但仍在安全范围内,满足了设计要求,为优化设计连杆提供了方案参考。

As one of the important parts of internal combustion engines, connecting rod is sub- ject to alternating tension and compression loads, which may lead to the failure of bolt, big head cap or connecting rod. In this paper, the stress distribution and fatigue strength were calculated and ana- lyzed in the limited condition by the finite element analysis. The calculation results showed that this particular type of connecting rod was over engineered which resulted in excessive weight. Based on the calculated results, the connecting rod was light-weighted and its geometry was optimized to re- duce the volume by 9.54%. Despite the marginally lower safety factor of the optimized connecting rod, it was still in the safe range and met the design requirements. This project provided a reference for the design of the connecting rod.