Nonlinear FEM analysis of inclined concrete-filled steel tube columns under vertical cyclic load

Abstract

This article presents the nonlinear analysis of inclined Concrete-Filled Steel Tube columns (CFST) under vertical cyclic loading using the Finite Element Analysis. Fifteen analysis cases with three inclination angles were investigated. All the steel tube columns were 75x75 mm. square section with 500 mm. long. The thickness of the tube was varied as either 1.8 mm. or 3.0 mm. The infilled concrete was 23 MPa and 42 MPa. The internal contact surface between the infilled concrete and the steel tube was applied. The validation of the finite element model was made through comparison with the test results. From the analysis and the test results, the ultimate cyclic compressive strength decreases with the increase of the inclination angle. However, the decrease of the ultimate load with the inclination angle (from 0 to 9 degrees) is smaller with the presence of the infilled concrete. The buckle section is perpendicular to the inclined member axis.