Interactive buckling of cable-stiffened steel columns with pin-connected crossarms

Cable-stiffened steel columns can significantly enhance the stability behaviour of ordinary compression columns because of the additional stiffness offered by the pre-tensioned cables and crossarms. Most of the previous studies aimed to investigate the behaviour of stiffened steel columns with four branch crossarm systems; however, the current work focuses on investigating the interactive buckling of cable-stiffened steel columns with pin-connected three branch crossarm system via buckling analysis. The analysis shows that the crossarms remain straight in the antisymmetric buckling mode, which distinguishes them from stiffened columns with rigidly connected crossarms. In addition, the interactive buckling must be considered in nonlinear buckling analyses in some cases to obtain the actual capacities of the stiffened columns. The method to consider the interactive buckling is to introduce asymmetric initial geometric imperfections during buckling analysis; the principle to form the asymmetric initial imperfections is suggested.