CRACK INITIAION STRENGTH OF STRUCTURAL STEEL MEMBERS HAVING EXPERIENCED LARGE COMPRESSIVE STRAIN

摘要

In the present report, an attempt was made to quantify the crack initiation strength for structural steel members having experienced large compressive prestrain due to buckling collapse. First, a tension test of the prestrained material was performed on JIS SS400 steel. The influence of prestraining on the mechanical properties of the material was investigated. Next, a crack initiation test and an elastoplastic large deformation FE-analysis for strip specimens were performed. The specimens were bent into various curvatures after undergoing buckling and the relationship between crack initiation and applied straining was examined. Finally, in order to investigate the crack initiation behavior for structural members subjected to cyclic bending load after undergoing buckling collapse, a crack initiation test and an elastoplastic large deformation FE-analysis for strip specimens under cyclic bending load were performed.