JM积分在低强钢焊接接头应力腐蚀破裂计算中的应用

THE APPLICATION OF J M INTEGRAL IN PREDICTION OF STRESS CORROSION CRACKING OF LOW STRENGTH STEEL WELDED JOINT

运用悬臂弯曲应力腐蚀破裂（ＳＣＣ）试验的方法，研究了低强钢焊接接头的应力腐蚀裂纹（ＳＣｃｒａｃｋ）的亚临界稳定扩展问题．提出了用弹塑性断裂力学（ＥＰＦＭ）参量ＪＭ描述应力腐蚀裂纹尖端应力应变场；分析了在ＳＣＣ条件下ＪＭ的计算方法，通过试验与计算测得了焊接接头各区的ｄａ／ｄｔＪＭ曲线。

An investigation has been made of stress corrosion crack(SC crack)subcritical stable propagation in low strength steel welded joint in boiling mixed nitrate solution by the use of pre cracked cantilever beam bend speciments.A J like parameter, J M integral, is employed to characterize the stress and strain at the SC crack tip and to predict the crack growth rate d a /d t .A methodological analysis of calculating J M in the condition of stress corrosion cracking(SCC)is given.A group of typical curves of crack growth rate d a /d t vs. J M are obtained.The sensibility of different regions in the welded joint to SCC is also investigated.