Seismic design and performance of concrete-filled composite plate shear wall coupled with steel side-columns

The composite plate shear wall/concrete-filled (C-PSW/CF) system is a structural element consisting of two steel faceplates with concrete infilled between them. It has demonstrated its efficiency in accelerating construction speed and superior lateral force resisting performance in terms of strength, stiffness, and dynamic properties. However, under extreme earthquake events, an isolated C-PSW/CF system with a large height-to-depth ratio may still suffer severe damage at its bottom region due to stress concentration. To improve material efficiency, reduce damage concentration, and enhance post-quake repairability, the coupling mechanism is introduced by joining steel columns to the C-PSW/CF on both sides using replaceable steel link beams at floor levels, forming the concrete-filled composite plate shear wall coupled with steel side-columns. The steel link beams are intended to uniformly distribute the plasticity development to the entire height of C-PSW/CF and to dissipate most of the seismic energy through inelastic deformation. To validate this idea, nine C-PSW/CF coupled systems are designed considering different structural heights and coupling ratios using an energy-based plastic design approach. Numerical modelling techniques for the C-PSW/CF coupled system are developed and verified through the comparison between the simulated and experimental results of traditional two-pier coupled C-PSW/CF systems. Then these nine C-PSW/CF coupled prototype structures are modeled and analyzed using pushover and nonlinear dynamic analyses. Results show that the C-PSW/CF coupled systems can be designed to meet the desirable performance objectives and preferred yielding mechanism. The majority of the steel link beams yield and develop considerable inelastic deformation before the failure of the C-PSW/CF. The coupling ratio significantly influences the structural response.