Prediction of brittle fracture initiatedtoeast growing from weld defectsofductile cracks

为了研究缺陷尺寸、尺寸和延性裂纹扩展数量之间的关系，设计了一种焊接板弯模型，该模型用于描述任意截面梁与带贯通横隔板的RHS柱构件之间的连接。测试结果支持预测；脆性断裂发生在缺陷的尖端。并尝试对骨折时刻进行预测。用考虑裂纹尖端塑性约束的J值预测的弯矩与试验结果基本吻合。

Welded plate bend models, which were designed to represent a connection of anI-section beam to an RHS column member with through diaphragms, were tested under cyclic loads in order to investigate the correlation of defect size, dimensions and quantity of ductile crack growth. Test results supported prediction; brittle fracture occurred from tips of defects. It was attempted to predict the fracture moment. The predicted moments using J values which were taken into account plastic constraint of crack tips roughly coincide with the test results.