Experiment Study On Deformation Performance And Hysteretic Characteristic Of SRC Columns

In order to implement the performance-based seismic design(PBSD)for steel reinforced concrete(SRC)structures, the following studies on SRC are carried out: (1) Six half scale SRC columns are tested under cyclic loading; (2) The limit state of SRC columns for different performance levels is discussed and the drift limit for different performance levels are recommended;(3) A restoring force model of SRC columns is proposed, which is capable of considering the effect of axial compression ratio on the hysteretic characteristics of SRC columns;(4) An analytical model of SRC columns is established and a nonlinear numerical analysis simulating the whole test process is carried out.Based on the test results, the failure patterns, hysteretic curves, skeleton curves, ductility coefficients, energy dissipation, stiffness degeneration and strength decay of SRC columns are comprehensively analyzed. The effect of axial compression ratio and stirrup ratio on the seismic performance of SRC columns is especially investigated.Based on the existing experimental results, the limit states of SRC columns for four different performance levels are discussed. The crack width and stress level of longitudinal bar, residual deformation and degree of strength decay are suggested as the appraising parameter of four performance levels,respectively. According to the experimental results of SRC columns, the drift limit for fully operation, operation, repairable and collapse avoidable are suggested as 1/250, 1/150, 1/50 and 1/35~1/25, respectively.Based on the experimental study, a restoring force model of SRC columns is proposed, which is capable of considering the effect of axial compression ratio on the hysteretic characteristics of SRC columns. The skeleton curves are set up based on a fiber section analyses and a statistics regression analysis. By analyzing the characteristics of the P-? hysteretic curve of SRC columns, a series of hysteretic rules for SRC columns is proposed.An analytical model of SRC columns is established with the versatile FEM software-ANSYS, and a nonlinear numerical analysis simulating the whole test process is carried out. The analysis results indicated that the results of calculation agree well with the test results.