Modelling concrete slabs subjected to localised fire action with OpenSees

Abstract

Reinforced concrete slabs in fire have been heavily studied over the last three decades. However, most experimental and numerical work focuses on long-term uniform exposure to standard fire. Considerably less effort has been put into investigating the response to localised fires that result in planarly non-uniform temperature distribution in exposed elements. In this paper, the OpenSees for Fire framework is presented, verified against benchmark solutions, and validated against experimental tests. The thermal wrapper developed within OpenSees is then presented and used to apply localised fire exposure to the validated slab models. It is seen that the deflections produced by the localised fire exposure are less than the standard fire exposure. It is also shown that by using the damage perimeter from the concrete damage plasticity model developed for OpenSees it is possible to predict the degree of cracking in the top layer each fire model is expected to produce.