汽车车身结构点焊的数值模拟与试验

Numerical Simulation and Research on Vehicle-body Welding

采用试验和有限元数值模拟的方法,对汽车车身低碳钢电阻点焊的过程进行了研究。利用电、热、力有限元法对电阻点焊的过程进行了模拟,得到了焊接电流、电极压力等工艺参数及焊件厚度对熔核尺寸的影响关系,从而确定了其与接头质量的关系。模型初步实现了热、电、力三者的耦合,得到的工艺参数对焊接接头质量影响的模拟结果与试验结果表明车身的试验模态模型以及计算模态模型能较好地吻合。

The resistance spot welding process of mild steel was studied by experimental and finite element methods. The results indicated that the relationship between process parameters（such as welding current, electrode force and plate thickness） and nugget size, from which the relationship between process parameters and the quality of joints has been derived. The results also showed the reason for expulsion through theoretical and FEM （finite element method） analysis by taking account of the effect of the contact state on thermal and electrode process. Electromagnetic thermal and structural fields have been carried out to verify the models established for analyzing spot welding, and the results showed that numerical simulation of spot welding is practicable.