Analysis of steel–concrete composite column subject to blast

The single-degree-of-freedom method is commonly used to approximate the dynamic response of structures subjected to blast loading. One of the limitations of this method is that it cannot capture the multi-failure modes of the structural members. The rigid–plastic method is thus, proposed in this paper as an alternative analytical approach to estimate the blast response of concrete-filled steel composite columns. The rigid–plastic results are compared with single-degree-of-freedom calculations as well as numerical simulations in order to assess the competency of the proposed method. Due to the assumption of rigid–plastic material behaviour in the rigid–plastic analysis, the accuracy of this method is influenced by the extent of plastic deformation of the structural member. For the case of impulsive blast loading, the rigid–plastic estimations are found to be closer to the numerical results than those obtained using the single-degree-of-freedom method. Numerical analysis was also conducted to compare the performance of concrete-filled steel composite column to a reinforced concrete column. A significant improvement in the blast resistance of the composite column was observed from the comparison.