Very Low Cycle Failure Process of Steel Angle Members

Abstract

This study investigates damage process to steel structural members after buckling by subjecting them to large repetitive deformations such as strong earthquake loading up to the ultimate cracking state. Experiments were conducted on steel angle members that were subjected to very low cycle loading that caused global and/or local buckling and plastic elongation. In this study, very low cycle loading means repetitive loading, five to 20 loading cycles, within the large plastic range. The objective of the experiments was to quantify the relationships of the important physical factors relating cracks and ruptures to large repetitive deformations. Also, a nonlinear finite-element-method analysis was performed to trace the experimental behavior of the steel structural members. Both the experimental and analytical results are comprehensively discussed with emphasis placed on the crack initiation process at the local buckling location. It is found that the FEM analysis effectively clarifies the detailed behavior of the steel members that has not been observed through the experiments, especially the behavior of local stress-strain histories at their cracking parts.