Experimental verification of a newly developed implicit creep model for steel structures exposed to fire

The paper presents a newly developed numerical model for the behaviour of steel structures exposed to fire capable of taking into account the effect of steel creep at high temperature by using an implicit creep model, as well as the experimental verification of the model. The purpose of the implicit model is to modify the stationary stress–strain curves of the material. After reaching temperatures above 400 °C, the stress–strain curves are modified, i.e. stretched, by using a calculated value of creep strain depending on the level of the stress, temperature and time. Verification of the newly developed implicit model was carried out on three in-house experiments that were specifically designed to induce creep strains in simply supported steel beams. Results of the experiments have shown good agreement with the model predictions, indicating the applicability of the implicit model for modelling the response of axially unrestrained steel members.