Finite Element Modeling of SMA-Confined Concrete: Influence of Winding Pitch and Temperature on Strength and Energy Dissipation

This study presents a detailed finite element investigation of concrete cylinders confined with shape memory alloy (SMA) windings, focusing on the combined effects of winding pitch and temperature. The main objective is to evaluate how geometric configuration and thermal activation influence the compressive strength, ductility, and energy dissipation of confined concrete. The nonlinear response was modeled in ABAQUS using the Concrete Damaged Plasticity (CDP) framework for the concrete core and a user-defined FORTRAN subroutine to simulate the reversible austenite–martensite transformation of the SMA. The numerical model was validated against laboratory data, showing strong agreement between simulated and experimental stress–strain curves. Parametric analyses were performed for winding pitches of ۵.۳, ۹, and ۱۶ mm under temperatures of ۳۰, ۵۰, ۷۰, and ۹۰ °C. The results demonstrate that decreasing the winding pitch substantially enhances post-peak stability and energy absorption, while higher SMA temperatures improve confinement efficiency at large strains without significantly altering peak strength. The study confirms that tighter and thermally activated SMA windings provide more uniform stress distribution and superior energy dissipation. These findings highlight the potential of SMA-based active confinement as a reliable and adaptive strategy for seismic retrofitting and impact-resistant design of concrete structures.

کلیدواژه ها:

Shape memory alloy ، Concrete confinement ، Finite element modeling ، Energy Dissipation