Appraisal of partially restrained steel columns in nonsway frames

This paper describes an analytical study to investigate the behavior of subassemblages with a range of semirigid connections under different test conditions and loading arrangements. The [[Alpha].sub.plan] concept, which gives an indication of the benefit of the restraint from the beam-to-column connection after incorporating the potentially disadvantageous influence of moment through the connection, is validated. It is noted that the M-[Phi] response is of fundamental importance and the success or failure of semirigid design methods rests on it. However, it is the most difficult parameter to determine accurately. The results in this study have shown that significant variations of the M-[Phi] response have a negligible effect on the load carrying of the column and the behavior of the subassemblage. This implies the precise form of the M-[Phi] response is not important for the column capacity of braced frames. Due to the boundary condition of the model, these results only translate into the braced frame behavior.