Performance-Based Experiment Research on Three-Story Concrete-filled Steel Tubular Frame

To study the seismic performance of concrete-filled steel tubular(CFST) frame structure, the quasi-static test on a three-story frame structure consisting of square CFST column and rectangular CFST beam was carried out. The hysteretic behavior, ductility, bearing capacity, stiffness degradation, energy dissipation capacity and other performance indicators were studied, and finite element simulation was used to analyze the mechanical behavior of concrete-filled rectangular steel tubular beams. Results show that the hysteretic curve of concrete-filled steel tubular frame structure is plump. Its ductility coefficient is greater than 3. The inter-story drift ratio falls in the range of 1/43 to 1/27. The inter-story plastic deformation capacity decreases with the increase of slenderness ratio of frame column and the stiffness ratio of the beam and column. The equivalent viscous damping coefficient is within the range of 0.115 to 0.441. The strength degradation is not obvious, but the stiffness degradation is more obvious. With the increase of load, if the beam or column yields, the neutral axis gradually moves to compressive zone; and the tension zone of concrete reaches the maximum area when load reaches the maximum.