薄板焊接残余应力和变形的数值模拟

Numerical Simulation on Welding Residual Stress and Deformation of Sheet Metal

运用ABAQUS有限元分析软件,结合子程序对腹板和翼板厚度均为2mm的T型薄板进行焊接及焊后热处理的温度场和残余应力场的数值模拟。模型采用三维实体单元,利用间接耦合方法,并且考虑了材料热、力物理性能随温度的变化和对流散热的影响。针对薄板TIG焊的特点,采用移动双椭球热源模型进行模拟。计算结果表明,采用移动双椭球热源模型进行模拟时,其应力分布特征与理论的残余应力分布一致。此外,经过热处理后,其应力均有很明显的降低。

The finite element analysis software ABAQUS and subroutines were used to simulate the temperature field and residual stress field during the welding and post weld heat treatment processes of T-plate whose dimensions of flange and web is 2 mm. 3D solid elements were used in the model. The method of sequentially coupled thermal- stress analysis was also used. The thermophysical properties, physical properties and heat convection which were changed with the change of temperature were taken into consideration. Based on the characteristic of TIG welding method in thin plate, the moving heat model of double ellipsoid heat source was used. The results show that the distribution of stress is in accordance with that in theory when simulating with the use of double ellipsoid heat source model. Besides, the stress decreases apparently after heat treatment.