Repeated loading and unloading of steel material in fire

Abstract

ABSTRACTThe effects of permanent strains on the use of a group of stress‐strain curves defined at different temperatures for modelling the steel material under repeated loading and unloading in fire are studied using finite element (FE) method. As a benchmark test for numerical simulations, experimental results received from the literature for a restrained beam exposed to fire including heating and cooling stage are used. The behaviour of both statically determinate and indeterminate steel members are studied using Abaqus/Explicit solver. The mechanical response of the studied members are well predicted based on the assumptions made for the modelling of steel materials in the design‐fire considering the cooling stage. However, the results highlight the need for further studies of modelling the behaviour of steel material subjected to temperature oscillations as in the case of travelling fires.