基于有限元的发动机连杆可靠性分析

摘要

For one engine connecting rod, using the finite element method combining with basic theory of modal analysis, the fatigue life of connecting rod, modal vibration mode and the resonance area are obtained thought the reliability analysis was carried out on the connecting rod. The analysis results show that the point closing to small head position is the weakest points and the fatigue life is minimum. The graphs which the big end hole location X, Z direction displacement changes as excitation frequency and the regions where easy to produce resonance are obtained during connecting rod working process through harmonic anslysis, allowing designers to predict the continuous dynamic characteristics of connecting rod and providing a theoretical basis of the structural design and the future design optimization of the connecting rod .%以某发动机连杆为研究对象，基于有限元方法结合模态分析基本理论，对连杆进行了可靠性分析，得到了连杆的疲劳寿命、模态振型和共振区域。分析结果表明，连杆在发动机工作过程中承受复杂的载荷，连杆小头与杆身过渡部位疲劳寿命最小，也是连杆设计的薄弱环节。最后对连杆进行了谐响应分析，得到了连杆大头孔位置处X、Z方向位移与激励频率的关系曲线，找到易发生共振区域，从而使设计人员能够预测连杆的持续动力特性，为连杆的结构设计或者进一步的优化设计提供理论依据。