A simplified model to predict blast response of CFST columns

In order to study the dynamic response of concrete-filled steel tube（CFST） columns against blast loads,a simplified model is established utilizing the equivalent single-degree-of-freedom（SDOF） method,which considers the non-uniform distribution of blast loads on real column and the axial load-bending moment（P-M） interaction of CFST columns.Results of the SDOF analysis compare well with the experimental data reported in open literature and the values from finite element modeling（FEM） using the program LS-DYNA.Further comparisons between the results of SDOF and FEM analysis show that the proposed model is effective to predict the dynamic response of CFST columns with different blast conditions and column details.Also,it is found that the maximum responses of the columns are overestimated when ignoring the non-uniformity of blast loads,and that neglecting the effect of P-M interaction underestimates the maximum response of the columns with large axial load ratio against close range blast.The proposed SDOF model can be used in the design of the blast-loaded CFST columns.