Flexural Behavior of Concrete-Filled Double-Skin Tubes Subject to Blast Loading

Abstract

Large-scale tests on concrete-filled double-skin tubes, composed of pairs of concentric cold-formed rectangular hollow section members with the annulus between them filled with grout, are performed under air-blast loading. The recorded data from the field tests, along with further laboratory experimentation, are used to validate numerical models developed for single-degree-of-freedom and explicit finite-element analysis. The influence of several key variables on the response of concrete-filled double-skin tubes is ascertained by means of a parametric study. Overall, the ultimate moment capacity is found to have a stronger influence on the response than do mass, stiffness, hollowness ratio, or confinement factor. The results of this investigation are used to provide design guidance for the use of these members in protective design applications.