Influence of Key Parameters on the Load–Displacement Response of FRP-Confined Concrete Columns: A Finite Element Investigation

This study investigates the influence of key parameters on the load–displacement response of fiber-reinforced polymer (FRP)-confined concrete columns through advanced finite element (FE) analysis. Building upon the previously developed numerical model for simulating the behavior of FRP-confined column[1],, the present work extends the investigation to assess the effects of critical parameters, namely the column diameter-to-length ratio, concrete compressive strength, FRP spiral pitch (spacing), and FRP type (CFRP or GFRP). The nonlinear response of concrete was represented using the Hognestad stress–strain relationship, while FRP confinement was modeled as a linear elastic–brittle material up to rupture. The FE results reveal that increasing the diameter-to-length ratio and concrete compressive strength enhances both axial load capacity and initial stiffness. In contrast, reducing the spiral pitch significantly improves ductility and energy dissipation. Furthermore, the type of FRP was shown to govern overall confinement efficiency, with CFRP generally providing superior stiffness and strength compared to GFRP. Overall, the findings provide valuable insights into the role of geometric and material parameters in shaping the structural performance of FRP-confined concrete columns, offering guidance for their design and optimization in engineering practice