强度失配对接接头残余应力分布的有限元预测

Prediction of residual stresses distribution in strength-mismatched butt joints using finite element method

针对高强钢的低匹配接头应用,采用有限元计算的方法,考察了匹配比、盖面焊道加宽对对接接头残余应力分布的影响.结果表明,强度匹配的影响虽仅限于包围焊缝的小区域,但该小区域包含了疲劳破坏的所有危险区域;随匹配比增加,焊趾横向残余应力降低,纵向残余应力增加;随焊道加宽低匹配对接接头的横向残余应力和纵向残余应力仅稍有增加,但峰值位置改变,普通低匹配对接接头横向残余应力峰值位于母材区,而焊道加宽的等承载设计对接接头横向残余应力峰值位于焊趾.

The influence of mis-match ratio and total width of cover pass on distributions of welding residual stresses are studied by finite element method for the application of undermatching butt joint of high strength steel.Although the weld strength mismatch effects are confined to a small region in the weld,all critical zone of fatigue failure such as weld toe and root of weld are located in this region.At weld toe,the magnitude of the longitudinal residual stresses increases and the magnitude of transverse residual stress decreases with increasing mis-match ratio.The magnitudes of the longitudinal residual stresses and transverse residual stress increase less with the increasing of total width of cover pass,but the position of peak value changes.The peak value of transverse residual stress of generic undermatching butt joints is located at base metal,but that of equal load-carrying undermatching butt joint corresponding to the increasing of total width of cover pass is located at weld toe.