Numerical Modeling of Concrete-Filled Double-Skin Steel Square Tubular Columns under Blast Loading

Abstract

Concrete-filled double-skin tubes (CFDST) have been widely used in constructing high-rise buildings, arch bridges, and factories over the past years. Although a number of researches have been conducted to study the behavior of CFDST columns under a variety of loading conditions, their performance when subjected to lateral impact load is still lacking. In this paper, numerical models of CFDST columns with two different cross sections are developed: one is with a CHS (circular hollow section) outer and CHS (circular hollow section) inner, and the other one is with SHS (square hollow section) outer and SHS (square hollow section) inner. Conventional concrete is filled in double-skin steel tubes. Different blast loads are applied to the surface of these columns for dynamic analysis. In addition, different axial loads are also applied to simulate combined load conditions. The displacement-time history obtained from each simulation is recorded and then compared. The key parameters that affect the performance of CFDST columns under blast load are also investigated.