[提要]根据现行钢结构工程施工质量验收规范对不同质量等级焊缝缺陷值的规定，以断裂力学为基础，通过模拟接头在循环荷载作用下裂纹的扩展过程，分析不同质量等级焊缝缺陷对焊接接头的强度和运行寿命的影响，提出循环荷载作用下对接接头焊接缺陷的控制建议值。

[关键词] 焊接接头 缺陷 疲劳性能 断裂力学

According to the value stipulation of defect with different quality ranks of welds in present construction quality check formulae, the crack developing process of a joint under circulating loads is simulated with fracture mechanics analysis method, and the manufacturing defect influence with different quality ranks on the strength and safe life of the joint is analyzed. The recommendable value in control of defect in welded joints under circulating loads is put forward.

Keywords: welded joint; defect; fatigue property; fracture mechanics