Experimental Research And Numerical Simulation Of Concrete-Filled Double Skin Steel Tubes-Columns

Along with the development of composite structures, the square concrete filled steelTubes (CFDST) have been widely applied in engineering practice, and achieved goodresults. In the late80s, the concrete filled double skin steel tubes (CFDST)as a new typeof concrete filled steel tube composite structures have been proposed.The concrete filleddouble skin steel tubes (CFDST) has all the advantages of the solid concrete filled steeltubes, and in severe, cross section and fireproof performance is superior to the solid co-ncrete filled steel tubes, so the concrete filled double skin steel tubes have the inestima-ble implementation prospect.The research for concrete filled double skin steel tubes is still in preliminary stage,and focused primarily on circular concrete filled double skin steel tubes (CFDST). Thispaper made the following several aspects for the square concrete filled double skin steeltubes (CFDST):(1). Proposed the research for performance of four square concrete filled doubleskin steel tubes (CFDST) column under repeated load test. The load-displacement curvefor square concrete filled double skin steel tubes (CFDST) column is recorded, on thebasis of drawing square concrete filled double skin steel tubes hydraulic component loa-d-displacement hysteresis curve, and use the polynomial trend line regression analysiswas carried out on the hysteresis curve, using the integral rule to calculate the compone-nt values of energy consumption and equivalent damping coefficient. The axial compre-ssion test has been done in the four square concrete filled double skin steel tubes (CFD-ST). The P-â–³curve has been recorded and drawing for axial compression load and vert-ical displacement, and vertical load and middle component transverse displacement.Collect the different position strain of outer steel tube different load by using the dyna-amic strain acquisition instrument, and analysis the changing strain for square concretefilled double skin steel tubes (CFDST) component under axial compression load.(2). On the basis of experiment, using the large general finite element analysis soft-ware Abaqus to carries on the numerical simulation. At the same time, considering thegeometric nonlinearity, physics nonlinear and contact nonlinear factors to establish areasonable model. The overall test process is Simulatied for the square concrete filleddouble skin steel tubes (CFDST) component column under repeated load and axial com- pression load. In order to determine the correctness of the finite element analysis results, the finite element analysis results were compared with the test results. In ensuring thatthe finite element modeling analysis method is feasible to analysis the internal and exte-rnal contact force between steel tube and concrete in the process of changing load. Anal-ysis the effect for the mechanics performance of the axial pressure under different waysof contact between steel and concrete interface. Finally, combining the previous analysisof research results, the simplified calculation formula and simplified calculation modelis to put forward for square concrete filled double skin steel tubes (CFDST).The results show that the square concrete filled double skin steel tubes has goodmechanical properties. Finite element analysis software Abaqus can effectively simulatethe test process. The contact force between steel and concrete interface has little effectfor stiffness and the bearing capacity of the component under the axial compression.