Studies of the behaviour of steel subframes with semi-rigid connections in fire

A series of analytical studies are presented on the behaviour of an unprotected 'rugby post' frame exposed to fire. The main purpose is to assess the effects of interactive structural behaviour on predicting the critical temperature for individual members. The influence of certain key parameters is considered, including the axial load applied to the column, the type of beam-column connection, and the rate of heating of the column relative to that of the beam. Where appropriate, the results are compared with current simplified design approaches. The studies indicated that the column load has a significant effect on the development of moments in the beam. It also became evident that, at failure, the maximum moment in the column is due largely to the effects of beam expansion. (C) 1998 Elsevier Science Ltd. All rights reserved.