Development of nonlinear model for slender concrete in-filled steel tube column

Abstract

Nonlinear analysis model to predict the monotonic force-deformation behaviour of concrete filled steel tube (CFT) column is developed. Geometric nonlinearities caused by the P-Δ effect and the material nonlinearities caused by the cracking of concrete are considered. In addition, the biaxial stress state in a CFT column section is simulated on the basis of a fiber model. An incremental-iterative numerical scheme based on arc-length method is adopted to solve the constructed nonlinear equilibrium equation. Developed model is validated by comparing the corresponding experimental results.