Experimental and numerical study on post-ultimate ductile performance of multi-celled concrete-filled steel tubular walls

Abstract

As a novel steel-concrete composite wall, the multi-celled concrete-filled steel tubular wall (MCFSTW) has been applied in a substantial number of mid- and high-rise building structures due to its excellent in-plane lateral resistance, sufficient out-of-plane stability capacity, good bearing capacity and convenience in construction. In this paper, six groups of single-cellular members of MCFSTW were tested under axial compression to investigate the post-ultimate ductile performance of MCFSTW. In the process of analyzing experimental data, residual strength and ductility indexes were used to quantify the post-ultimate performance of MCFSTW. It was found that as the width-to-thickness ratio increased, the residual strength and ductility indexes decreased. Then, a refined finite element (FE) model for MCFSTW was established by using the software Abaqus. After comparing the results obtained from the refined FE model with the experimental results in this paper and other literature, the validated FE model was used to further investigate the effect of changing different parameters (concrete strength, steel properties and sectional dimensions) on the post-ultimate ductile performance of MCFSTW. After detailed analysis, the ductility and residual resistance indexes of MCFSTW were found to be linearly correlated with the confinement coefficient. Finally, the prediction formulas of residual resistance and ductility indexes were proposed and they can be used in engineering practice.