基于模态叠加法的后背门焊点疲劳预测

Fatigue Prediction of the Tailgate Spot Based on Modal Superposition Method

传统的准静态方法不能覆盖开闭件动态响应造成的疲劳损伤,对车身进行基于模态叠加法的模态瞬态分析,同时考虑某车型后背门设计状态和实车状态的差异,分别对后背门焊点寿命进行仿真计算,复现了实车出现的焊点开裂现象,并对其造成的原因进行调查。通过此方法复现实车失效问题,说明了模态瞬态法在开闭件疲劳耐久分析中的准确性和必要性,同时可看出缓冲块对于后背门耐久性能的重大影响,对后背门开发过程有重要的指导意义。

The traditional quasi-static method does not cover fatigue damage caused by the dynamic response of opening and closing parts;in this paper,the modal transient analysis of the car body based on modal superposition method is carried out.At the same time,considering difference between the design state and the real state of the tailgate of a certain car,the spot life of the tailgate is simulated and calculated respectively.The spot cracking phenomenon of the real car is reproduced,and the causes are investigated.This method is used to solve the problem of vehicle failure,which illustrates the accuracy and necessity of modal transient method in fatigue endurance analysis of closure,and has important guiding significance for the development process of tailgate.