Non-linear study of base shear and moment of composite columns in MRFs

The main objective of this study is evaluating the seismic behavior of composite columns in MRFs subject to dynamic loads. The design Codes of composite structures contain different views in some cases and therefore conservative provisions, because of lack of enough information about the behavior of these structures. The base shear and moment of structures in non-linear state can be considered as criteria for the potential of a lateral-force-resisting system to dissipate the seismic energy. Lower values of nonlinear seismic base reactions indicate better efficacy of the system. In this study the performance of the MRFs with composite columns has been evaluated using 8-story structural models, considering the base reactions obtained from the non-linear analysis. The results show good performance of composite sections under the seismic loads. Also, a comparison between two types of composite sections, the full and half-embedded steel sections in concrete, has been made.