点焊连接的有限元建模方法研究及案例应用

Study and application on finite element modeling of spot welding connection

建立一种高精度和高效率的点焊连接有限元模型可以提高点焊结构的有限元分析精度。通过焊接钢板的试验模态与计算模态的对比分析,探讨并评价了4类焊点模型的模拟精度、建模优劣和建模时间,确定了ACM2模型和CWELD/ELPAT模型为薄板点焊连接有限元分析中的较优选择。利用HyperMesh、Nastran软件联合仿真,对某电动汽车电池包进行了模态分析和台架定频振动试验工况的模拟,结合试验结果,进一步评估了两种焊点模型的模拟精度和模型计算速度。结果表明,CWELD/ELPAT模型能准确模拟焊点位置、模拟精度高、建模时间短且模型计算速度快,适用于模拟电池包的点焊连接,为解决电池包因焊点数量多、焊点附近局部网格不协调、结点不对齐导致的点焊建模难点提供了参考,为电池包的有限元分析提供了有力支持,具有较好的工程意义。

Four elements and six solder joint models were discussed and evaluated in the aspects of coupling stiffness, simulation accuracy, strengths and weaknesses of modeling and modeling time by using finite element modal analysis method and combing with the free modal test of welded steel plate. It provided that ACM2 and CWELD/ELPAT are better for finite element analysis of sheet welding connection. The modal of the battery pack was analyzed and the working condition of the fixed frequency vibration test of the platform was simulated by the joint simulation of Hyperworks and Nastran. The result shows that CWELD/ELPAT has high simulation accuracy, short modeling time and accurate simulation of the locations of solder joints. It can be used for simulating the spot welding connection of battery pack to solve the grid discordance, node misalignment and some other difficulties in spot welding modeling and it gives strong supports for structure optimization and fatigue analysis of battery pack, which has a certain engineering significance.