Numerical Investigation on Cyclic Behavior of FRP-Reinforced SFRC Composite Walls Considering Bond-Slip Mechanism

To investigate the cyclic behavior of FRP-reinforced steel fiber reinforced concrete (SFRC) composite walls, this paper proposes a section-based finite spring calculation method (FSCM) to reliably predict the cyclic response of such walls under seismic loads. The proposed model accounts for the bond-slip effect of FRP bars and the confining action of transverse reinforcement in the boundary elements. Numerical calculations were conducted on six composite wall specimens with varying longitudinal bar types, fiber volume fractions, concrete strengths, and axial compression ratios. The results indicate that the established calculation method efficiently characterizes the “pinching” effect induced by the linear-elastic properties of FRP bars, and the obtained hysteretic curves are in good agreement with experimental data. Furthermore, the model accurately predicts the load-bearing capacity and residual displacements of the FRP-reinforced SFRC composite walls. Specifically, the average error of peak load calculation for all specimens ranges from −3.36% to 7.36%, and the predicted residual displacements correlate well with the experimental data. These findings demonstrate the applicability of the proposed model for key seismic performance indicators and provide a reliable basis for the research and engineering application of FRP-reinforced SFRC composite walls.