Finite Element Analysis of Bearing Performance of Concrete-filled Steel Tube Composite Frame under Thermal and Mechanical Coupling

The research on the mechanical characteristics of concrete-filled steel tubular composite frame under thermal mechanical coupling is one of the hot topics. In this paper, the finite element simulation software is used to analyze the concrete-filled steel tubular composite frame, and the failure characteristics of the concrete-filled steel tubular composite frame structure under the thermal coupling effect are introduced. The simulation results of the mechanical properties of the two-story and two span concrete-filled steel tubular composite frame structure are deeply studied, including the failure load, ultimate bending moment and mechanical properties of the composite frame under high temperature. The analysis of the mechanical properties of concrete-filled steel tubular composite frame under the condition of full section fire shows that the bearing capacity of the composite frame decreases with the rising temperature, and the redistribution is obvious at the key junction points, which eventually forms a mechanism and causes damage. The research results can provide reference value for strengthening and repairing of concrete-filled steel tubular composite frame under high temperature.