Research On Hysteretic Behaviour Of Concrete-filled Stainless Steel Tubular Columns

Concrete-filled stainless steel tube(CFSST),which has unique aesthetic and good durability of stainless steel as well as good mechanical properties of concrete-filled steel tube(CFST),can be treated as a new type of composite structure.CFSST can satisfy the request for utilization under harsh environment and have broad application prospects in engineering structures with higher requirements of corrosion resistance and durability,such as the offshore platform and coastal buildings.The domestic and international scholars had performed some research works on CFSST members;however,these research works paid more attention on static performance rather than hysteretic performance.In order to ensure the safety of CFSST structures in the seismic fortification area,it is necessary to study the mechanical properties of CFSST members under cyclic loading so as to evaluate the seismic performance of the new type of composite structure reasonably and provide basis for seismic analysis and design of CFSST structures.The main research work of this dissertation includes:(1)The experimental study on static performance and seismic performance of CFSST members,and the related theoretical research achievements were reviewed.(2)The experimental study of 18 CFSST columns under cyclic loading was carried out,and the effect of cross-section,steel ratio and axial compressive load ratio on the failure pattern,load versus deformation curves,bearing capacity,energy dissipation,stiffness degradation and ductility of the specimens was investigated.(3)Based on the determination of the combined hardening parameters of stainless steel under cyclic loading,the finite element analysis(FEA)model of CFSST columns under cyclic loading was established using the software ABAQUS.The FEA model was validated by comparing the numerical simulation results with the experimental results.(4)The lateral bearing capacity of the specimens is calculated using the simplified formulae in the technical code for CFST structures with carbon steel.The results show that the calculated bearing capacities were much lower than the experimental results.