Experimental and numerical investigation of corrugated steel plate-polygonal concrete-filled steel tubular stub columns under eccentric compression

Abstract

In this paper, an eccentric compressive test of eight corrugated steel plate-polygonal concrete-filled steel tubular columns (CSPP) was performed to explore the mechanical behavior and constraint effect. To explore the failure mode, ductility, stiffness deterioration, and strain distribution characteristics, the specimens were built using eccentricity and the corrugated steel plates' specifications as parameters. Experimental results indicated that the bearing capacity of CSPPs decreases by about 35% as the eccentricity increases from 0.2 to 0.8. The multi-cell of steel tube and corrugated steel plate can form a strong constraint and mechanical interlocking effect. Finite element analysis was conducted to evaluate the influence of different parameters and the interaction mechanism between steel and concrete. The results showed that corrugated steel plates' principal function is to constrain the core concrete and that their vertical load-bearing ratio is less than 5%. As the “skeleton” of the multi-cell, an increase in thickness and strength of steel tubes affects the bearing capacity of CSPPs and flexural performance substantially. The constraint effect of corrugated steel plates is not uniformly distributed in a period, and the variation in specifications of the has a compounding effect on CSPPs. Finally, a simplified calculation method was proposed for predicting the eccentric bearing capacity of the CSPPs, which is in good agreement with experimental and finite element results.