INFLUENCE OF LOADING REGIMES ON SEISMIC BEHAVIOR OF NEW TYPE STEEL REINFORCED CONCRETE COLUMNS

The aseismic behavior of new type steel reinforced concrete (SRC) columns was simulated based on the finite element software, and the calculated results were compared with experimental results to ensure the correcteness of the simulation model. Furthermore, with abundant simulations, the effect of loading paths, the cycle times of displacemensts, the amplitude increment of displacements and variable axial forces were studied on aseismic behavior of the new type SRC columns. Because a biaxial coupling effect exists in the column, the aseismic behavior of the columns under a biaxial cyclic loading path is much lower than those under a uniaxial cyclic loading path, which indicates that the aseismic behavior of the column is influenced significantly by the loading path. Before reaching the yield load, the skeleton curves are not significantly influenced by the cycle times of displacements, but significantly influenced after the yield load. The more cycle times of displacements the smaller the peak load as well as the corresponding horizontal displacement and the displacement ductility ratio are reached, but its energy dissipation is larger. The effect of the increment of displacements on aseismic behavior of the columns under a biaxial cyclic loading path is much more significant than those under a uniaxial cyclic loading path. The yield displacement, yield load, and displacement ductility ratio are increased with the increase of the increment of displacements, but the energy consumption is decreased. The column under a variable axial force shows asymmetry apparently, and it is more adverse than the one under a constant axial force in the aseismic behavior.