STABILITY BEHAVIOR OF SEMIRIGID SWAY FRAMES

Due to the inelastic behaviour of beam-to-column connections, the stability behaviour of semi-rigid steel frames is affected not only by the loading and unloading characteristics of connections at the critical points, but also by their prior load history up to these points. Thus, the analysis of inelastic critical and post-critical behaviour of semi-rigid frames becomes very complicated, when compared with that of the usual pinned or rigid frames. This paper utilizes a method developed by the authors to examine precisely how the stability behaviour of semi-rigid frames is influenced by factors such as modelling of connections, load conditions, geometrical imperfections, and the load history caused by cyclic wind load. Based on these results, the validity of the effective length factor as applied to the design of semi-rigid frames is discussed.