Simulation comparison of the dispersion behaviour of dry sand subjected to explosion

Abstract

This research simulated the dispersion behavior of sand subjected to explosion on the surface of a sand layer. The simulation was conducted using AUTODYN. Explosion effects from an explosive were achieved by using the computer program, Conventional Weapon Effects Backfill (CONWEB), which was based on field data compiled by the U.S. Army (US Army, 1986). Three different governing equations were used for air, sand and explosive. Ideal gas equation was used to equate the movement of air and the dry sand was based on the compaction effort. For the explosion, the JWL (Jones-Wilkins-Lee) equation was used. This paper presents the effect of explosion on the crater depth, crater diameter and overpressure exerted on sand and the surrounding air. The results have shown that crater depth and diameter increase with time during explosion. The experimental data on crater depth, however, were initially lower than the numerical simulation, but after 30 ms, it increased more than the numerical simulation. The overpressure showed a reducing trend with time. The numerical simulation, based on AUTODYN, predicted higher crater depth and overpressure at the initial stage, but showed a good agreement with the experimental data with time.