Elasto-plastic behaviour of plates subjected to heat loads

The collapse of steel plates subjected to thermal loads representative of fire conditions is analysed taking into account the temperature dependence of the steel properties. A brief description of the temperature dependence of steel properties is provided as well as the approach taken to account for their change during the heating process in the numerical algorithm. A series of calculations of load temperature curves is performed for plates of different aspect ratio, slenderness, initial imperfections and boundary conditions in order to established how they affect the temperature and the collapse load of the plates. If was observed that the maximum load carrying capacity of the plates is often reached at temperatures ranging from 100 degrees C to 200 degrees C, a situation in which the yield stress of the material has not decreased too much yet. The effect of the elastic support of the plates is important until collapse is reached, but afterwards it can be ignored. (C) 1998 Elsevier-Science Ltd All rights reserved.