Improved SDOF Approach to Incorporate the Effects of Axial Loads on the Dynamic Responses of Steel Columns Subjected to Blast Loads

In this paper, a complicated single-degree-of-freedom (SDOF) approach was developed to determine the global response of steel columns under combined axial and blast-induced transverse loads. Nonlinear section and member analyses were incorporated into the suggested SDOF method to account for the complex features of the material behavior, the high strain rate effect, and the column geometry. The SDOF technique was validated through comparisons with available finite element and experimental data, and a good consistency was obtained. Then, the validated SDOF approach was utilized to derive the pressure-impulse curves under various levels of axial loading. The level of the axial load was shown to have a significant influence on the dynamic behavior of a steel column subjected to a blast load.