Experimental and numerical investigation of charge shape effect on blast load induced by near-field explosions

Abstract

High explosives are hazardous materials that are frequently used in industrial production which involves many safety and risk problems. To investigate the influence of the explosive charge shape on near-field blast loads (<1.0 m/kg1/3 in this study), 12 shots of field blast tests were carried out. The reflected overpressures of 1 kg TNT with different charge shapes at a distance of 800 mm and the incident overpressures at a distance of 1310 mm were measured and analyzed. The fireballs produced by the explosions were recorded by a high-speed camera and compared with each other. Results show that the fireball of a non-spatial symmetry explosive is non-uniformly distributed, which indicates the released energy is also non-uniform. The charge shape effect was further investigated using a verified numerical model. The experimental and numerical results show that the charge shape has a significant effect on the key parameters of blast loads such as the incident overpressure, the reflected overpressure, and the impulse. However, the influence of the charge shapes crumbled away with the increase of scaled distance. When the scaled distance is larger than 5.0 (6.0) m/kg1/3, the hemispherical (cylindrical) charge shape effect on the reflected peak overpressure and the impulse can be neglected.