中厚板GMAW近缝区焊接传热的边界元计算

Computation of GMAW Welding Heat Transfer in the Vicinityof Weld Zones on Plates of Medium Thickness With Boundary Element Method

依据焊接准稳态传热的边界元计算模型,编制了计算机程序。对中厚板熔化极气体保护焊(GMAW)条件下常见的指状熔深的近缝区传热问题进行了计算,计算结果与实测符合较好。说明用边界元法分析焊接热过程是有效的,为焊接热过程的计算机模拟提供了新的数值分析手段。在进行焊接近缝区传热计算时,如果以熔池边界直接作为热源,则忽略材料热物理参数的非线性对计算精度没有明显的影响,因此焊接近缝区传热计算的关键是熔池形状的确定问题。

Based on the computation model for quasi-static heat transfer problems of welding with boundary element method , a computer program is developed and used for the computation of heat transfer in the vicinity of weld zones with gas shielded metal arc (GMAW) welding on a plate of medium thickness , in which the finger-typed penetration is often the case. The computed results are in good agreement with those from experiments showing the capabilities of boundary element method to deal with the simulation of welding thermal process. The computed results also show that little effect on the accuracy of computation occurs when the non-linearities of material parameters are neglected as the weld pool being taken directly as the heat source . Therefore the main point is the determination of the shape of the vicinity of the weld zone in heat transfer problems.