Abstract
In the foregoing paper (Research on the elasto-plastic analysis of steel section subjected to alternative lateral load, part 1-5), authors analysed the curvature of the cross section subjected to alternative fending moment and axial force, and proposed "A hypothesis of Shake Down load", in case of the symmetrical cross section subjected to alternative load. But in many experiments, it is well known that the effect of strain hardening in the stress-strain relationship, affecting the behavior of the steel structure, can not be ignored. In this paper, authors extended the foregoing theory to the case, in which the strain hardening in the stress-strain relationship was considered, and applied to the analysis of the portal frame. Four types of strain hardening models of the stress-strain relationship were considered, and in two cases, the behavior of the pinned-base portal frames subjected to alternative load were analysed, using the bi-linear type strain hardening model.
