Analytical Comparison of Various Models for Concrete-Filled Steel Tubular Columns Subjected to Cyclic Loading

The hysteresis behaviors of circular and square concrete filled steel tubular were analysed and compared with test results. Local buckling and stiffness degradation are considered for steel model, various simplified analytical models of confined concrete are adopted to verify the accuracy of simulations. Comparison results indicate that steel model adopted in analysis program can accurately perform the local buckling and degradation of steel tube. After comparing different types of confined concrete model, the strength degradation of concrete in circular steel tube could be ignored because of high-level confinement effect, while the strength degradation of the concrete in square steel tube should be considered contrarily. Furthermore, the simplified model based on Sakino & Sun\u27s proposal has the best accuracy on predicting the post-peak degradation behavior of square concrete filled steel tubes