Nonlinear finite element analysis of double skin composite columns subjected to axial loading

Abstract

The study aimed to simulate the behavior of the concrete-filled double skin steel tubular (CFDST) composite columns having a circular hollow section using the finite element method (FEM). To indicate the accuracy and the reliability of the model, the proposed FEM model was verified by the experimental test results available in the literature. Moreover, the code-based formulas (ACI, AISC, and Eurocode 4) and some empirical models suggested by the previous researchers for predicting the axial capacity of CFDST columns were used in this study to compare their results with the proposed FEM model. Furthermore, to visualize the effectiveness of sectional properties and infilled concrete compressive strength on the ultimate axial strength of double skin composite columns, a parametric study was conducted. For this, 72 test specimens were modeled considering two outer and inner steel tube diameters, three outer and inner steel tube thicknesses, and two different concrete cylinder strengths. All results were statistically evaluated. It was observed that the proposed FEM model had a good prediction performance. As well, the FEM model results indicated that the sectional properties, in particular, the diameter of the outer steel tube and concrete compressive strength, had remarkable effects on the load-carrying capacity of CFDST columns. © 2020, Wroclaw University of Science and Technology.