Numerical Study on Concrete Filled GFRP-Steel Tube under Cyclic Loading

For the purpose of investigating the strengthening effectiveness of GFRP on concrete filled steel tube structure under combined seismic loading and comparing with CFRP ones, numerical simulations of quasi-static test are developed by using ABAQUS. The establishment of finite element model is tested to be feasible by comparing the numerical load-displacement hysteretic curves and their skeleton curves with the experimental ones. Further studies are carried out through changing models' FRP (GFRP/CFRP) thickness, axial compression ratio and cross sectional steel ratio. Simulation results show that specimens with thicker FRP (GFRP/CFRP) equip better energy dissipation capacity and higher bearing capacity. In elastic-plastic stage the stiffness of specimen degradation becomes more serious as axial compression increases. Energy dissipation capacity is enhanced as cross sectional steel ratio increases.