Study on the LBB conditions of plates and pipes under cyclic load

The high stress, low cycle fatigue tests were carried out on HT80 plates, STS42 plates taken from pipes and STS38 pipes with artificial part-through notch. The LBB conditions by the net section stress approach was examined in detail, and configurations of through cracks immediately after penetration and crack propagation behaviors were closely studied. From the test results, it was noted that the LBB condition in fatigue test was dependent upon the maximun load change before and after the crack penetration. The LBB criterion by the net section stress approach shows to be dependent on initial crack size, independent on specimen sizes, specimen geometries and ductility of materials. (author)