Modelling of plane composite frames in unpropped construction

A computer program has been developed to analyse the behaviour of steel-framed buildings with composite floor decks, taking into account both geometric and material non-linearities. In order to simulate the real physical behaviour of a steel-framed building with a composite floor deck the analysis tool has been developed with the capability of predicting the behaviour of two-dimensional sub-frames during both the construction phase and the later composite-beam stage. Partial interaction between the steel beam and the composite slab, the orientation of the profiled metal deck, the effect of additional reinforcement over the support and the semi-rigid nature of the composite beam-to-steel column joint are all included in the analysis. Validation of the computer program against experimental results shows very good agreement not only in terms of load-deflection response but also on load–joint rotation and load-reinforcing bar strains. A description of the mathematical formulation of the four distinct finite elements which have been used in the program is given in Appendix A.