A study on a theoretical relationship between strain hardening of steel and plastic region length in a steel beam subjected to fire

This paper presents a relationship between strain hardening of steel and plastic region length in a steel beam subjected to fire. A theoretical simple fire response analysis is proposed to investigate elasto-plastic behavior of the statically indeterminate heated beam. From observation of parametric calculations, it is clarified that large plastic region length in the beam, which is induced by the large strain hardening, is effective to avoiding strain concentration. This contributes to the robust attenuation of the thermal stress at the fire.