The influence of shear connectors on the behaviour of composite steel-framed buildings in fire

A three-dimensional non-linear procedure is presented for modelling partial shear connection in composite steel-framed buildings in fire. The model ha s been incorporated within the computer program VULCAN which has been devel oped to model such structures. The accuracy and reliability of the model ar e demonstrated by analyses of four previously tested simply-supported compo site beams, of which two were tested at ambient temperature, and a major fu ll-scale fire test conducted in the Cardington composite test frame. The mo del is clearly capable of predicting the response of composite members and structures in fire with acceptable accuracy, although data is needed on the degradation of shear stud connectors at elevated temperatures. It is shown that, in statically determinate components, the local failure of shear stu ds can very rapidly alter the behaviour at the failure temperature, althoug h whether this is important depends on the loading level. The inclusion of partial interaction is shown to make a small, but potentially significant, amendment to the analytical results in the high temperature range for the t hree-dimensional full-scale fire test. (C) 1999 Elsevier Science Ltd. All r ights reserved.