Study on Shock Initiation of Covered Composition B by Multiple Fragment Impacts

Abstract

In order to investigate the interaction between double spherical tungsten fragments and Composition B (Comp B) covered by tantalum coverplates, the numerical simulation was carried out by using AUTODYN-3D software. The influence on the shock initiation characteristics of double fragments at various distance separation b1, time separation h1, impact angle α with the same or different velocities were analyzed, and the critical initiation velocity of covered Comp B was obtained. The obtained simulation results show that, under certain circumstances, the superposition effect of shock waves caused by double fragments impact on covered Comp B is obvious. The critical initiation velocity increases with the increase of b1 when fragments impacting on covered charge at the same time with same or different velocities, with α=0, and approaches critical velocity of a single fragment. The critical initiation velocity decreases initially and then increases with the increase of h1 when fragments impacting asynchronously on covered charge with different velocities and α=0. When fragments impacting synchronously on covered Comp B with different velocities, the critical velocity decreases initially and then increases with the increase of α. When fragments impacting asynchronously on covered Comp B with different velocities, the critical velocity increases with the increase of h1. Therefore, a shock initiation of covered Comp B rather be achieved by multiple fragments at lower velocity than by a single fragment at higher.