Cyclic elasto-plastic analysis of steel members

This paper is concerned with the cyclic elasto-plastic analysis of steel members subjected to the combined axial force and bending moment by employing the two-surface plasticity model in force space (2SM-FS). First the basic concepts of the 2SM-FS and procedures for determining its parameters are presented. Then the accuracy of the 2SM-FS is verified by comparing cyclic nonlinear sectional behavior of steel members obtained from the 2SM-FS with those of the experiments and analysis using the two-surface model in stress space (2SM-SS). Finally by employing the 2SM-FS for sectional nonlinear behavior in a beam-column element formulation, cyclic elasto-plastic analysis of steel members, such as fixed-ended beam-columns and cantilever columns, are carried out. The cyclic plasticity performance of the 2SM-FS is discussed and is verified against the experiments and numerical results using 2SM-SS. It is shown that both the 2SM-SS and 2SM-FS accurately predict cyclic behavior of steel members while the 2SM-FS has the advantage of larger computational speed than that of the 2SM-SS.