Abstract

According to Eurocode 3, Merchant-Rankine approach can be used for second order plastic analysis of plane steel frame. This approach suggests an experimental equation to predict the ultimate resistance of plane steel frame with rigid structural joints. The ultimate collapse load factor is calculated from first-order rigid-plastic load factor and elastic critical frame buckling load factor. A Matlab program was built up to calculate the ultimate collapse load factor of plane steel frame with rigid structural joints, in which the First-order Hinge By Hinge Analysis Method was used to determine first-order rigid-plastic load factor and the Two Cycles Iterative Method was used to determine the elastic critical frame buckling load factor, the second-order analysis was made by the Finite Element Method.