Experimental Research On Seismic Behavior Of Concrete-filled Rectangular Steel Tubular Columns

Because concrete-filled steel tube (CFST) can take advantage of the two kinds of material of steel tube and concrete fully, nowadays, it has already been used widely in the engineering practice. But, the section shapes are mostly circular and square. Though the restriction effect of the steel tube of concrete-filled rectangular steel tube to core concrete is not as good as concrete-filled circular steel tube, concrete-filled rectangular steel tube has many advantages, such as easier to connection with beams, good ductility, and so on, people has become to attach importance to it. But seismic behavior study of the concrete-filled rectangular steel tube is not very mature. Because of increasing use of concrete-filled rectangular steel tube in actual projects, it is necessary to make further study of seismic behavior of CFST.In this paper, five concrete-filled rectangular steel tube columns are designed, the depth-to width ratio of section is 1,1.25,1.5,1.75, 2, and the quasi-static test was done to it. Analyzed the destroy shape, bearing capacity, ductility and ability of deformation, hysteresis behavior, ability of consume energy, intensity degradation, rigidity degradation of specimens, and so on. Utilized the finite element software-ANSYS8.0 to imitate the the situation of concrete-filled rectangular steel tube frame columns under low cycle reverse load, to summarize the impact of depth-to width ratio of section on seismic behavior of concrete-filled rectangular steel tube.The result of study indicate that the load-displacement hysteretic curves has good stability and fullness, there is no obvious rheostriction phenomenon, therefore, these columns have good ability of consume energy and ability of plastic deformation The depth-to width ratio of section not only influence value of curve, but also influence the shape of curve. As the depth-to width ratio of section augment the level bearing capacity increase obviously, but ductility, ability of deformation and ability of consume energy descend, and intensity degradation, rigidity degradation and influence of slippage to specimens become more obviously. Have carried on non-linear finite element analysis to concrete-filled rectangular steel tube through finite element software ANSYS8.0, its calculation result and the test result are identical well. So ANSYS have certain precision of calculation, it can simulate the reality of structure under load comparatively accurate, has offered the effective analytical method for design of the structure.