汽车滑动门焊点疲劳有限元分析方法及应用

Fatigue Finite Element Analysis Method and Application of Automobile Sliding Door Solder Joint

文章提出一种解决某样车滑动门在开闭耐久试验中出现焊点疲劳开裂问题的有限元仿真分析方法。该方法以考虑焊接熔核及焊接缺陷的精细有限元模型为研究对象,以超单元法对该模型进行简化,根据标记样件疲劳断裂试验结果,获得以精细超单元法评价焊点寿命的特殊S-N曲线。然后将该方法应用到汽车滑动门的疲劳耐久试验有限元仿真模型中,并根据Miner线性疲劳累计损伤理论,标定出评价滑动门耐久试验中焊点寿命的评价方法。最后利用该方法对试验中的疲劳问题进行了优化,并以试验手段验证了该方法的可行性。该方法能准确地预测滑动门开闭耐久试验中焊点寿命,提高计算效率,节省开发费用,具有一定的工程实用价值。

In this paper,a FEM is proposed to solve the fatigue crack problem of the sliding door in the durability test.In this method,the fine finite element model considering welding nugget and welding defects is taken as the research object,and the model is simplified by super element method.According to the fatigue fracture test results of standard samples,a special S-N curve for evaluating the service life of solder joints by fine super element method is obtained.Then,the method is applied to the FE model of sliding door for the fatigue durability test.According to Miner s linear fatigue cumulative damage theory,the evaluation method of fatigue life of weld in sliding door s durability test is calibrated.Finally,the method is used to optimize the fatigue problem,and the feasibility of the method is verified by the test method.This method can accurately predict the life of weld in the durability test of sliding door,and improve the calculation efficiency,as well as reduce the development cost,so as to have a good effect on engineering application.