Numerical Simulation of the Axial Load Effects on Lateral Deformation of Concrete Filled Double Skin Steel Tubular under Blast Loading

According the increasing use of concrete filled double-skin steel tubular (CFDST), this study investigate the effect of axial compressive force on the lateral deformation caused via blast wave by using numerical simulation by AUTODYN software. For this purpose, CFDST with square section and different levels of axial load (p/pu from 0 to 80%) were modeled and subjected to 35 Kg TNT explosion loading. The current research shows that the residual and maximum displacements as well as columns’ damage index caused by blast load are decreased with increasing axial compressive load for lower values of axial force, but by exceeding the axial force over 0.6 of ultimate capacity, the aforementioned parameters are increased. Compared when using plates of different thickness, the minimum deformation and damage could be achieved by applying steel sheets of the same thickness for external and internal cover.