EXPERIMENTAL RESEARCH OF ASEISMIC BEHAVIOR FOR CONCRETE-FILLED RECTANGULAR STEEL TUBULAR FRAME JOINTS

Through quasi-static test of three concrete-filled rectangular steel tubular (CFRST) frame joint (exterior stiffened ring) models, the parameters include the axial load level and beam-column linear stiffness level, the hysteretic curve, ductility, degradation of strength and stiffness , failure mechanism and characteristics are researched. The results indicate that the CFRST frame joints has plump hysteretic loops, stronger energy dissipation capacity, slower strength and stiffness degradation, better ductility and late deformation ability after the joints reach ultimate loads, the ductility coefficient is between 3.5 and 4.48,the joint can meet the requirement of ductile joint. Compared with reinforced concrete frame joints, composite structure frame joints, steel frame joints, the CFRST frame joints has superior mechanical behavior and aseismic capacity; the research fruits can direct the engineering practice of concrete-filled steel tube structure.