Load-carrying capacity of circular concrete filled steel tubes under axial loading: Reliability analyses

Abstract

This paper presents the results of reliability analyses of load-carrying capacity of circular concrete filled steel tubes (CFST) using different codes. Four parameters that govern the load-carrying capacity of CFST were considered as variables. These variables include the yield strength of steel, the strength of concrete, the diameter of CFST, and the thickness of the steel tube. The Monte Carlo technique was used for the simulation. Simulations were conducted, and the obtained load-carrying capacities were analysed. The results indicated that the load-carrying capacity of circular CFST follows a normal distribution. Eurocode 4 provided the highest mean load-carrying capacity because the confinement effect was taken into consideration, whereas the mean load-carrying capacity obtained from the American Institute of Steel Construction (2016) and Architectural Institute of Japan (AIJ, 2008) codes were similar. All considered variables resulted in higher standard deviations and coefficients of variation, while the thickness of the steel tube resulted in the lowest standard deviation and coefficients of variation. Therefore, the reliability indices obtained from all considered variables are lowest while those obtained from the variable of thickness are highest.