ABSTRACT
ABSTRACT: It is often necessary to determine the behaviour and time to collapse of a frame subjected to the action of a fire. Given the time – temperature relationship for a plane timber or steel frame, the paper shows how a collapse analysis of the frame could be conducted. The effect of temperature with time on the timber and steel properties and thus on the members is considered. The effect of charring is also considered. Iterative non-linear analyses are done for selected temperature distribution increments. The geometric non-linear (or second-order) effects are considered and the changes inmaterial andmember properties are taken into account to compute action effects. The member (out-of-plane) resistances are also computed. Given a factored imposed load case, the collapsemode and the time to collapse can be determined. The procedure is described with the help of a flow diagram.
