Analytical and numerical study on the cyclic behavior of buckling-restrained SMA-based self-centering damper

Abstract

Owing to the unique superelasticity and satisfactory energy dissipation capacity, shape memory alloys (SMAs) show great potential in earthquake engineering. This study focused on establishing analytical method and finite element (FE) model for the buckling-restrained SMA (BRSMA) based self-centering (SC) dampers. For the BRSMA-based SC damper, the lateral deformation of the slender SMA component is constrained by the surrounding buckling-restrained plates (BRPs). Hence, the SMA component avoids buckling induced instability and the damper accordingly exhibits stable cyclic behavior under tension–compression loadings. Although the compressive behavior has been obtained through cyclic loading tests, an in-depth understanding on the corresponding force-displacement relationship is required. As such, a simple analytical method was proposed for estimating the compressive strength capacity of the BRSMA-based SC damper. Besides, the FE model was built to provide additional information that was difficult to obtain in physical model tests. The accuracy of the analytical method and FE model was confirmed by the testing results. The verified FE model was further used to conduct the parametric analysis. The parameters of interest included the shape of the reduced section, the dimension of the BRSMA components, the gap between the BRSMA components and BRPs and the number of bolts. The findings of this paper not only promote understanding on the cyclic behavior of this new damper, but also provide suggestions and guidelines for future design.