T型板焊缝处埋藏式裂纹扩展特性研究

Study on Propagation Characteristics of Buried Crack in T-plate Weld

针对焊接T型板焊接处埋藏式裂纹扩展进行研究,依据相互作用积分法及最大周向应力准则,结合ANSYS软件,对含埋藏式初始裂纹的T型板试件模型在疲劳荷载的下的裂纹三维扩展进行模拟,获得T型板焊缝埋藏式裂纹的扩展规律,最后采用Forman公式评估埋藏式片状裂纹的剩余寿命。结果表明:埋藏式裂纹扩展主要表现为张开型扩展,初始椭圆球缺陷只影响裂纹扩展初期阶段的平面形状,当裂纹扩展到一定程度后,其平面形状会趋近于圆形直至扩展至构件表面,同时裂纹扩展后波浪形空间形态也说明不能忽略Ⅱ和Ⅲ型裂纹的影响。

Based on the interaction integral method and the maximum circumferential stress criterion,combined with ANSYS software,this paper simulated the three-dimensional crack propagation of T-shaped plate model with embedded initial crack under fatigue load,and obtained the propagation law of T-shaped plate weld embedded crack.Finally,Forman formula was used to evaluate the residual life of embedded flake cracks.The results show that the propagation of embedded crack is mainly open type,and the initial ellipsoid defects only affect the plane shape of the initial stage of crack propagation.When the crack propagates to a certain extent,its plane shape will tend to be circular until it extends to the surface of the component.At the same time,the wavy spatial shape after crack propagation also indicates that the influence of mode II and III cracks can not be ignored.