Seismic response analysis of single-degree-of-freedom structure coupled with tuned self-centering wall

Abstract

This paper investigates the possibility of using self-centering walls (SCWs) as tuned mass dampers (TMDs) to control the seismic response of structures. The basic characteristics of this system are investigated using a two-degree-of-freedom (2-DOF) model, representing the main structure as a single-degree-of-freedom (SDOF) oscillator interconnected with an SCW through viscous and elastic devices. The nonlinear equations of motion for the proposed coupled system are derived and then utilized to determine the displacement amplification response. The coupling parameters are optimized to minimize the dynamic response of the oscillator using a numerical method. A simulation study is conducted to investigate the response of the proposed system by considering six recorded earthquakes. Several parameters are studied, including the mass ratio, the influence of prestressing, and the slenderness angle of the wall. The displacement spectra are generated using the optimized parameters and compared to those of the uncoupled system and the traditional coupled system, which features a rigid connection between the structure and the wall. The results reveal that the proposed system effectively suppresses both maximum and root mean square responses of structures, outperforming the traditional coupled system in most cases. Improved performance for the proposed system can be achieved by increasing the wall's mass ratio and decreasing the slenderness angle. Moreover, prestressing has an adverse impact on the system's displacement response. Finally, the influence of wall flexibility is examined using a finite element model, revealing a minimal effect on the system's response.