边界约束对焊接残余应力及其释放的影响分析

Numerical calculation on welding residual stress and release considering boundary constraint effects

采用热弹塑性有限元方法对AH36船用高强度钢对接焊的残余应力进行数值计算,获得了焊缝区域2条路径方向上的纵向残余应力和横向残余应力分布。分析焊接过程中板材不同边界约束对于焊接残余应力的影响,并与试验结果对比。计算结果表明,2条路径上的横向焊接残余应力均受边界约束影响较大,且约束越强残余应力越大;纵向焊接残余应力受边界约束影响与横向残余应力相反,约束越强残余应力越小。随着边界约束增强,加载同样循环次数,无论横向还是纵向焊接残余应力释放程度增加,第一次循环释放量占总的50次循环释放量比例逐渐增加。

In this paper,the thermo-elastic-plastic finite element method is used to calculate the residual stress of butt welding of AH36 marine high-strength steel.The longitudinal and transverse residual stress distributions in the directions of two paths near the weld zone are obtained.The influence of different boundary constraints of the plate on the welding residual stress during the welding process is further analyzed and compared with the test results.The calculation results show that the transverse welding residual stresses in the two path directions are greatly affected by the boundary constraints,and the transverse residual stress increases with the constraints becoming stronger.Contrary to transverse welding residual stress,the longitudinal residual stress decreases with the constraints becoming stronger.As the boundary constraint is enhanced,and the degree of release of transverse and longitudinal welding residual stress increases with the same number of cycles of loading,and the release proportion of the first cycle to the total of 50 cycles is gradually increased.