考虑多裂纹的焊趾裂纹扩展行为的数值仿真分析

针对焊趾处存在多裂纹的情况，对多裂纹扩展过程进行了数值仿真.考虑短裂纹扩展阶段，采用M积分计算整个裂纹前沿的应力强度因子，模拟并分析了不同初始表面裂纹间距条件下，该因素对裂纹前沿融合前后的扩展行为的具体影响.结果表明，裂纹间距的不同将直接导致其对整个裂纹前沿前后的应力强度因子的影响的差异；受初始裂纹间距的影响，裂纹前沿断口形貌呈现不同形状；可将相对裂纹间距L/a=1分界拐点作为后续工程研究的有效参考.后续进行了十字焊接接头疲劳验证试验，对仿真结果取得了较好的验证.

Numerical simulation analysis of crack propagation in weld toe considering multiple cracks

Aiming at the existence of multiple cracks at the weld toe, the numerical simulation of the multi-crack propagation process was carried out. Consider the short crack growth stage. The M-integral is used to calculate the stress intensity factor of the entire crack front. The specific influence of this factor on the propagation behavior before and after the fusion of the crack front is simulated and analyzed. The results show that the difference in crack spacing will directly lead to the difference. The influence of the stress intensity factor before and after the fusion of the crack front is different. The shape of the crack front has different shapes due to the initial crack spacing. The relative crack spacing L/a=1 boundary inflection point can be used as an effective reference for subsequent engineering research. The fatigue test of the cross-welded joint was carried out, and the simulation results were verified.