The effect of joints on the stability behaviour of steel frame beams

Abstract The influence of joint construction on the lateral-torsional behaviour of steel frames is investigated. Commonly used beam-to-column connections with various stiffening arrangements are analysed in order to determine their effect on the stability behaviour of the whole structure. Through finite element modelling of portal frames, it is established that a consistent relationship exists between the critical load for lateral-torsional buckling of the frame beams and the joint design. A comparison between the critical loads obtained from the finite-element method, and those derived from the equivalent-member method, leads to a derivation of reliable coefficients that simulate joint-type behaviour and facilitate a simplified and effective analysis of frame beams.