Calculating Method For Bearing Capacity Of Concrete-filled Stainless Steel Tubular Members And Its Application

Concrete-filled stainless steel tube(CFSST)combines the advantages of concrete-filled steel tube(CFST)and stainless steel has high bearing capacity,good ductility and durability.Moreover,CFSST has beautiful appearance and is easy for maintenance.As a result,CFSST has been applied in several modern engineering structures,such as Hong Kong Stonecutters Island Bridge,New York Hearst Building,etc.At the same time,the composite performance of CFSST members is different from that of carbon CFST members due to the obvious material nonlinearity and strain hardening property of stainless steel.Therefore,it is necessary to investigate the performance and mechanism of CFSST members subjected to complex loadings,and further to provide the simplified calculation method for bearing capacity.The works completed in this paper are as follows:(1)The research achievements of CFSST members in the literature were reviewed and an experimental database including 125 circular CFSST members(64 under axial compression,25 under bending and 36 under eccentric compression)and 175 square CFSST members(94 under axial compression,23 under bending and 58 under eccentric compression)was also constructed.(2)The suitability for bearing capacity calculation of CFSST members using the simplified method in the literature and the design formulae in the codes for carbon CFST was discussed based on the comparison between the calculated and measured results.(3)Based on the determination of the constitutive model of stainless steel and core concrete,finite element analysis(FEA)models for CFSST members under axial compression,bending and eccentric compression were established using the software ABAQUS,and the accuracy of the FEA model was verified through the comparison between the simulated and experimental results.(4)Based on the validated FEA model,the influence of parameters on the bearing capacity of CFSST members was systematically studied,and the simplified calculation method for the bearing capacity of CFSST members was further suggested.Finally,the feasibility of the formulae in this paper and the methods in the literature for the bearing capacity of practical CFSST members was comparatively analyzed.The achievements in this paper can provide a reference for the engineering practice.