Experimental Study And Numerical Analysis On Steel Reinforced Concrete Compression-bending Members

Steel Reinforced Concrete (SRC) is a new structure system developed from steel structure and concrete structure. It is widely used in high-rise buildings for favorable seismic behavior and mechanical behaviors.According to the known reference, researches on SRC columns mainly focus on the short columns with the failure mode of shearing, and the long columns with the failure mode of bending are neglected. To study the seismic behavior of SRC compression-bending members, eighteen SRC columns with the span ratio of 4.23 are tested under low cyclic reversed loading. By analyzing the failure patterns, hysteresis loops, skeleton curves, ductility coefficients and energy dissipation capacity of such members, the influence of axial compression ratio and stirrup ratio on seismic behavior of SRC compression-bending members are discussed.The experimental results indicate that the SRC compression-bending members exhibit favorable ductility and energy dissipation capacity, which decrease when increasing the axial compression ratio and increase when increasing the stirrup ratio. Base on the test data, the interrelated formula between ductility and stirrup ratio of SRC compression-bending members under different axial compression ratio are put forward.An adequate embedded depth is needed for the SRC compression-bending members to work. The mechanical behavior and seismic behavior of SRC specimens with different embedded depth are compared by the test. According to the test results, a minimum embedded depth of 2.5 times height of the steel cross is proposed for SRC compression-bending members in this paper.Nonlinear finite element analysis of the test specimens are carried out using the ABAQUS software. The whole process in FEM analysis, including choosing material model, creating geometry model, meshing the model, applying loads and computing are introduced. The analysis results are compliance with the test results.A computer program based on flat section assumption and fiber model is compiled using strip method to simulate the test specimens' response under axial load and monotony horizontal load. The moment-curvature curve and load-displacement curve of the test specimens are obtained from that program. The simulate results also accord with the test results.