对熔合线上含裂纹焊接接头,应用有限元方法分析了其应力应变场的分布规律。与以往研究中假设裂纹位于焊缝中间的情况相比较,指出了熔合线含裂纹焊接接头,由于裂纹位置的变化造成了裂纹结构由张开型演化为张开型和剪切型裂纹的复合型—Ⅰ+Ⅱ型裂纹模式。结合裂端的位移场,对其COD断裂参量的分解进行了讨论。更进一步,对其复合角及复合比例进行了数值计算,指出了复合角的影响因素和焊接接头分析的复杂性。 The cracked welded joint on the fusion line is analyzed by finite element method. Compared with the assumption that the crack is located in the middle of the weld in the previous study, it is pointed out that the crack in the fusion line contains the cracked welded joint and the crack structure evolves from the open type to the composite type with the open type and the shear type due to the change of the crack location -Ⅰ + Ⅱ crack mode. Combined with the displacement field at the crack tip, the decomposition of COD fracture parameters is discussed. Furthermore, the composite angle and composite ratio were calculated numerically, and the influencing factors of compound angle and the complexity of welded joint analysis were pointed out.