对接焊残余应力的有限元分析

Finite element analysis of butt-welding residual stresses

针对应用有限元方法进行焊接残余应力数值预报时模拟普遍存在的三维模拟过程复杂、计算时间冗长、计算费用较高的问题,通过引入焊接热循环过程的加热和冷却时间比,提出了以线热源代替点热源的简化数值预报方法,使三维问题简化为二维问题进行数值模拟,大大节省了计算时间。数值计算结果表明:文中提出的焊接残余应力的数值预报方法能满足焊接力学分析的精度要求,节省了大量的计算时间,可以应用于工程实际。

A simplified method is developed to overcome the shortcomings in ordinary finite element methods for welding process simulation and welding residual stress prediction,such as complicated process, long running time and high cost. The method adopts the liner heat source instead of point heat source by introducing a time ratio of heating and cooling during the welding process,so that the 3-D problems are transformed into 2-D problems and save the running time a lot.The numerical results show that the present method is capable of predict welding residual stress in practical engineering and a large amount of running time and computer resources are saved under the condition of quite high accuracy.