Research on the seismic performance of self-centering concrete-filled superelastic Cu-based SMA tube columns

To address the issue of significant residual deformation in conventional concrete-filled steel tube (CFST) columns subjected to seismic loading, this study proposes two configurations of self-centering shape memory alloy (SMA) tubular concrete columns: single-tube and double-tube systems. In these configurations, traditional steel tubes are replaced with cost-effective Cu-Al-Mn SMA materials. Thermal treatment and cyclic tensile tests were conducted on Cu-Al-Mn SMA plates. Based on the experimental results, the constitutive model parameters for the finite element analysis of Cu-Al-Mn SMA plates were determined. Following the validation of the finite element model's accuracy against existing experimental data on CFST columns, a parametric finite element analysis was performed to assess the seismic performance of the single-tube and double-tube self-centering concrete columns. The experimental results indicate that both the single-tube and double-tube self-centering columns exhibit enhanced self-centering capabilities, leading to a significant reduction in residual deformation. Additionally, comparative analysis among five distinct column configurations demonstrates that the three self-centering variants achieve markedly lower residual deformation. Data availability: All data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.