Abstract

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Title:: Nonlinear Analysis of Concrete-filled Steel Tubular Columns Under Blast Load

Author(s):: CAO Xue-ye; ZHAO Jun-hai; LI Yan; School of Civil Engineering, Chang’an University

Keywords:: blast load; concrete-filled steel tubular column; unified strength theory; plastic ultimate moment; equivalent single degree of freedom model; step by step integration method

Abstract:: The plastic ultimate moment of concretefilled steel tubular and the ultimate displacement of the simply supported beam under uniformly distributed load were derived based on unified strength theory. Considering nonlinear impact of mass and stiffness changed in the process of the reaction, the dynamic responses of concretefilled steel tubular columns under blast load were analyzed by the equivalent single degree of freedom model and step by step integration method. The results of this method were compared with relevant literatures and the accuracy of the method was verified. The study results show that the plastic ultimate moment and the ultimate displacement increase along with the increase of hoop coefficient; the plastic ultimate moment also increases along with the increase of lateral pressure coefficient; the plastic ultimate moment considering the improvement of the compressive strength of concrete increases 12%19% than that without considering the improvement. The proposed method is satisfied for the requirement of the analytical precision, and can be referred for the research and the safety of concretefilled steel tubular columns under blast load.