Quasi-static loading procedure of CFS framed shear walls considering ground motion duration

Abstract

Cold-formed steel (CFS) structures framed with CFS framed shear walls exhibit clear characteristics of strength and stiffness degradation during seismic events, thus the influence of ground motion duration on their seismic responses should not be ignored. The purpose of this study is to construct a quasi-static loading procedure for CFS framed shear walls considering the effect of ground motion duration, which can help to acquire accurate shear performance of the walls and lay a foundation for evaluating the actual seismic performance of the structures. The main research contents and results are as follows: (1) sixty ground motions were selected and adjusted to be spectrally equivalent records, which ensured that the effect of the ground motion duration could be decoupled; (2) nonlinear time-history analysis of eight CFS framed shear wall models were performed, whereafter, considering the influences of both structural responses and the input energy of ground motions, a determination method for the number of loading cycles of the quasi-static loading procedure was proposed, and a prediction model for the number of loading cycles was established; (3) the influence of the amplitude distribution of the quasi-static loading procedure was analysed, and a value range of the amplitude distribution parameter was suggested. Finally, a method to construct the quasi-static loading procedure for CFS framed shear walls was formed and verified.