Experimental and Numerical Investigation of Steel-Concrete Composite Fluted Columns under Axial Compression

Abstract

This study presents a comprehensive experimental and numerical investigation on Steel-Concrete Composite Fluted (SCCF) pillars to estimate their organizational presentation under axial compression. A total of 12 fullscale specimens were tested experimentally, and 135 limited component models were analyzed consuming ABAQUS software to examine the influence of flute geometry, number of flutes, diameter-to-thickness (D/t) ratio, and length-to-diameter (L/D) ratio on load-carrying capacity and bond strength. Results demonstrate that SCCF columns with four outward rectangular flutes exhibit superior performance, achieving up to 75% increase in ultimate load capacity equated to conventional concrete-filled steel tube (CFST) pillars. The experimental findings were validated through finite element analysis with less than 9% variation. Bond strength tests revealed that outward fluted columns achieved 8-32% higher bond strength than conventional CFST columns. Nondimensional interaction curves were developed based on EC-4 guidelines, and an empirical formula for predicting bond power was proposed. The study confirms that SCCF columns with optimized flute configuration provide enhanced structural performance, making them suitable for high-performance composite structures in civil engineering applications.