Experimental and Theoretical Study of Fragment Safety Distance of Fragmenting Munitions

Abstract

The fragment safety distance is an important requirement for test and evaluation of the munition stores in the field trials. It determines the area to be cleared or evacuated before conduct of any trial activity. In this paper, theoretical and experimental work is carried out for establishing the explosive parameters and its interaction with the metallic casing. High explosives are used for controlled fragmentation to generate specific–size-and-weight fragments with lower velocity. Empirical relationship based on high strain rate and Gurney energy criteria were applied and optimized. Two prototypes having two different type explosive filling were fabricated to generate the fragment data. This enables to determine the safety distance useful for conducting trials in small ranges with required safety. The experimental data reveals that 90% fragments of a definite shape and size have been generated. The recorded fragment velocity was of the order of 250 to 400 m/s. Based on these data, safety distance was calculated and found to be about 400 m. Experimentally, fragments were recovered and found up to 130m from the point of burst.