Finite Element Analysis Of High-strength Concrete-filled Steel Tubular Columns Under Eccentric Compression

Abstract

This study presents a numerical investigation of the compressive and flexural behavior of short circular concrete-filled steel tubular (CFST) columns composed of high-strength materials under eccentric loading. A total of 27 specimens were analyzed using three-dimensional nonlinear finite element models developed in Abaqus, in which both the steel tube and concrete core were modeled using solid elements. The investigated parameters included D/t ratios of 18–43, eccentricity ratios of 0.2–0.6, steel yield strengths of 355–460 MPa, and concrete compressive strengths of 100–110 MPa. The results indicate that the structural response is governed by the combined effects of geometry, material properties, and loading eccentricity. Increasing the eccentricity ratio from 0.2 to 0.6 reduced the initial stiffness and ultimate load capacity by approximately 60–70%, reflecting a transition from axial-dominated to bending-controlled behavior. In contrast, higher steel and concrete strengths improved the axial capacity, whereas larger D/t ratios reduced the load-carrying capacity due to increased susceptibility to local buckling. Failure was characterized by steel yielding and local buckling accompanied by concrete cracking and crushing, together with significant stress redistribution under eccentric loading. The findings provide valuable insight into the behavior and design of high-strength CFST columns subjected to combined compression and bending. It has significant applications in both infrastructure engineering and the sustainable development of the built environment.