Experimental And Theoretical Research On Seismic Behavior Of Concrete-filled Rectangular Tubular Frame

In the study of Concrete-filled Steel Tubular Structure, the Concrete-filled RoundSteel Tubular Structure has been studied for many years, lots of achievements hadbeen obtained and its theoretical research and engineering application become moreand more sophisticated;on the other hand, the study of Concrete-filled RectangularSteel Tubular Structure has been started for a few years, and mostly concentrate on themechanical behavior of basic members rather than the performance of wholeConcrete-filled Rectangular Tubular Frame. In this paper, based on the quasi-statictest, the experimental study on seismic behavior of both Concrete-filled RectangularTubular Column and Frame were carried out.1. Experimental study on seismic performance of columns of Concrete-filledRectangular Tubular Frame. According to the steel ratio, slenderness ratio and axleload ratio, 9 pieces of column of Concrete-filled Rectangular Tubular Frame wasdesigned and tested under low reversed cyclic loading in which the bearing capacity,hysteretic behavior and characteristics of ductility, performance of plastic deformation,stiff degeneration, the abilities of seismic energy dissipation and failure mechanism ofthe columns were analyzed under seismic horizontal loading. Testing result shows thatthe load-displacement hysteretic curves has good stability and fullness, therefore,these columns have good ductility, good performance of deformation and seismicbehavior.2. Experimental study on seismic behavior of Concrete-filled RectangularTubular Frame. Based on a quasi-static test of two-span, three-storey Concrete-filledRectangular Steel Tubular Frame (CRSTF), the bearing capacity, hystereticcharacteristics, ductility and performance of plastic deformation, stiff degeneration,the properties of seismic energy dissipation and failure mechanism of CRSTF areanalyzed. Also, according to hysteretic curves of the top storey, the correspondingframework curve and resilience model of CRSTF are deduced. The test shows theload-displacement hysteretic curve is a diamond shape which is stable and fullness,and has a good ductility and ability of deformation, energy dissipation and bearingcapacity. It is satisfactory for CRSTF to meet the seismic properties required forgeneral ductile frame.3. Nonlinear Finite Element Method (FEM) analysis of the seismic behaviors ofCRSTF. Based on the experimental testing, the theoretical analysis using non-linearFEM for CRSTF is carried out, and the computing program for element stiffnessmatrix using hexahedron 8-node isometric element is completed in which theresilience model is applied into the degeneration equation of concrete elastic module.At last, the course of testing is simulated by commercial software ANSYS, thesimulated hysteretic curves are achieved and compared with the experimental result.Result shows, combined with the theoretical research achievement from this paper,ideal effect have been obtained by using the computer simulation for the course oftesting.