Effect of Obliquely Directed Brick TNT Explosive on Slab Response under Contact Explosion

Abstract

To design defense infrastructures and facilities, available prominent resources namely UFC 3-340-02, TM 5-1300, ASCE/SEI 59-11 and IS 4991, primarily consider test results from spherical explosives detonations whereas most of the explosives used in warfare and industrial/conventional operations have cylindrical/brick geometric form. Available research works in the literature considering various aspect ratios of cylinder TNT with its longitudinal axis perpendicular to the slab and of brick TNT having its length parallel to the supports and with its length and breadth in contact with the one-way slab, demonstrate that out of the three geometric forms (cylinder, sphere, and brick) of the explosive of the same mass; cylindrical explosive generates maximum pressure and the brick explosive produces the minimum. The authors discern that the obliqueness of the brick/cylindrical explosive with reference to the boundary condition of the slab influences the energy distribution and corresponding slab damage. In this paper, the effect of obliquely directed brick TNT explosive on slab response under contact explosion is examined in Abaqus software with a focus on comparing the slab damage and other responses with varying obliqueness of the explosive from 0° to 90° with increments of 22-1/2 degree. The numerical findings of the brick explosive having its length aligned with the slab supports demonstrate a strong correlation with the experimental results. The findings indicate that the maximum reflected pressure varies with the obliqueness of the brick explosive and consequently affects the slab damage including perforation size and geometry.