OpenSEES-Based Seismic Performance Analysis of CFRP-Reinforced Concrete Column

To address durability issues in concrete structures caused by steel corrosion， this study proposed replacing steel reinforcement with carbon fiber-reinforced polymer （CFRP） tendons and systematically investigated the seismic performance of CFRP-reinforced concrete columns. Through low-cycle reversed loading tests on three full-scale specimens and OpenSEES numerical simulations， the influence mechanisms of key design parameters—including axial compression ratio （<italic>ν</italic>）， concrete strength， shear span ratio （<italic>λ</italic>）， longitudinal reinforcement ratio （<italic>ρ</italic>）， and stirrup ratio （<italic>ρ</italic>_s）—were elucidated. The results demonstrated that a threshold effect of axial compression ratio （<italic>ν</italic>）， beyond which the risk of reinforcement yielding surged and seismic performance deteriorated abruptly； unlike strength degradation induced by excessive <italic>ν</italic>， enhanced concrete strength significantly improved load-bearing capacity and energy dissipation but exacerbated brittle failure； increased shear span ratio （<italic>λ</italic>） shifed failure modes toward flexural dominance， reducing load capacity while the linear-elastic constitutive behavior of CFRP tendons limited energy dissipation enhancement； higher longitudinal reinforcement ratio （<italic>ρ</italic>） boost load capacity， delayed yielding initiation and stiffness degradation， and improved energy dissipation； stirrup ratio （<italic>ρ</italic>_s） exerted negligible effects on lateral stiffness but maintained post-yield strength stability through enhanced core concrete confinement at elevated ratios.