力学不均匀性对含横向裂纹焊接接头J积分的影响

摘要

Extended J-integral of different strength mis-matched welded joint containing transverse crack under plain stress condition and longitudinal load was calculated using a Delorenzi virtual crack extension method of MARC finite element program. The results show that mechanical heterogeneity has great influence on the J-integral of welded joint containing transverse crack. The J-integral on the path cross the interface between welded joint and base metal is higher than the J-integral on the paths in the weld metal for undermatched joint,while the J-integral on the path cross the interface between weld metal and base metal is lower than the J-integral on the paths in the weld metal for overmatched joint. Moreover,the difference of J-integral values increases with the increasing of the load and strength mismatching difference and the path-enclosed length of interface between weld metal and base metal. The influence of mechanical heterogeneity on the J-integral of welded joint containing transverse crack is mainly caused by the strength mismatching and the length of interface between weld metal and base metal.%采用MARC有限元程序提供的Delorenzi虚拟裂纹扩展方法计算了平面应力条件下不同强度匹配的焊缝纵向受载的含横向裂纹的焊接接头在不同载荷的广义J积分。计算结果表明：力学不均匀性对含横向裂纹焊接接头的J积分有重要影响，低匹配焊接接头中积分路径穿越焊缝与母材界面的J积分值高于积分路径在焊缝内的J积分值，高匹配焊接接头中积分路径穿越焊缝与母材界面的J积分值低于积分路径在焊缝内的J积分值；载荷越大，焊缝与母材的强度差别越大；积分路径中包含的焊缝与母材界面长度越大，J积分的差值越大。力学不均匀性对焊缝纵向受载的含横向裂纹的焊接接头J积分的影响是由焊缝与母材的强度差别及积分路径中包含的焊缝与母材界面长度的不同造成的。