Seismic performance evaluation of infilled CFS shear wall structures based on equivalent nonlinear analysis model

Cold-formed steel (CFS) walls with infilled material have become more and more popular due to their improvement in strength and stiffness of the walls. Previous studies have proved the structural advantage of gypsum-filled CFS shear walls. However, when applied in structural systems, there are lack of guidelines in seismic design for the novel CFS shear walls. In this paper, on basis of previous gypsum-filled CFS shear wall tests, the simplified model based on equivalent line elements was put forward and verified. The results indicate the proposed simplified model can effectively simulate the hysteretic behavior of the walls, which can be applied to analyses of structural systems. And then the reduction response factor R was developed on basis of tests and Newmark method, which played an important role on seismic design. Based on proposed reduction response factor R and simplified model, the archetype structures were designed and their 3D models were built. And then a series of pushover analyses and incremental dynamic analyses were conducted to evaluate the collapse performance of the structures. The results indicate that reduction response factor R of 4.6 for the gypsum-filled CFS shear walls can be employed in seismic design.