平板焊接接头裂纹扩展中残余应力重分布的数值模拟

Numerical simulation of redistribution of residual stress in the crack propagation of plate butt-welded joint

高强度钢平板焊接接头在焊趾处易萌生表面裂纹,裂纹的产生和扩展均会对其焊接残余应力产生一定的影响,进而影响残余应力对结构疲劳强度影响的评估。首先采用ANSYS的APDL语言编写平板焊接接头残余应力数值模拟程序,得到完整结构的初始焊接残余应力的分布规律。然后采用Zen Crack软件模拟半椭圆型初始表面裂纹,并分析结构在出现初始裂纹后残余应力的分布规律。最后施加循环疲劳载荷进行裂纹扩展分析,得到裂纹扩展中的残余应力的重分布规律。

The surface crack is easily generated on the weld toe of the high strength steel plate butt-welded joint. The generation and extension of the crack will have a certain effect on the welding residual stress. Therefore, the assessment of the effect of residual stress on fatigue strength of structure will be affected. Firstly, a numerical simulation program of the welding residual stress of the plate welded joint with ANSYS APDL language is carried out in this paper, and the distribution law of the initial welding residual stress is obtained. Then, the initial semi-ellipse surface crack is simulated by Zen Crack software, and the redistribution of the residual stress after appearing initial crack is achieved. At last, the redistribution of the residual stress during the crack propagation is also achieved with the cyclic loading.