随机载荷下燃油泵托架疲劳寿命仿真分析

针对一类含橡胶减振垫燃油泵托架出现疲劳断裂的现象,研究利用数值仿真技术预测结构疲劳寿命的方法。应用有限元法和随机振动理论计算结构随机振动响应的各种统计参数,采用Miner累积损伤理论预测疲劳寿命。重点讨论了有限元模型中系统阻尼和橡胶垫刚度等关键参数的确定方法,并利用优化技术实现有限元模型修正的自动化。计算结果表明动态随机激励环境下存在严重的局部应力集中是造成托架损坏的主要原因。仿真结果和随机振动试验结果吻合,证明利用数值仿真技术预测此类产品的疲劳寿命是可行的。

Simulation Analysis of Fatigue Life of Fuel Pump Bracket Under Random Load

Using numerical simulation technology,we study a method for predicting the structural fatigue life of a fuel pump bracket(FPB) that contains rubber cushion for vibration reduction.Finite element analysis and random vibration theory were applied to calculating the various statistical parameters of its random vibration responses.Based on the responses,its fatigue life was predicted using the Miner cumulative fatigue damage theory.Its damping,the stiffness of its rubber cushion and other key parameters were determined.An optimization technique was employed to achieve the automatic correction of the finite element(FE) model.Calculation results show that the stress concentration under random excitation is the main cause for the damage of the FPB.The numerical simulation results demonstrate the feasibility of the proposed method.