Efficiency of a collective action of solid projectiles upon an obstacle at a oderate impact velocity

Pulsed Loading of Objects during Intense Expansion of Products of Explosion of Solid Explosives (Review)

“…The metallographic study of rescued specimens, performed by N. A. Yukina [56], revealed the following results. There are cracks and discontinuities in surface layers of through holes and craters.…”

“…The experiments of [52][53][54][55][56] show that expansion of explosion products of solid HE charges by a factor of 10 2 -10 3 generates moderate-intensity mechanical pulsed actions of various physical origin: 1) unsteady air shock waves with pressure profiles "extended" in time (Figs. 5 and 6) with amplitudes p max ≈ 10-10 2 MPa and durations t 0.1 ≈ 10 −4 -10 −3 sec at the level of 0.1p max ; 2) fluxes of solids (steel spheres with a weight of ≈0.5 g each) moving with velocities of the order of 1 km/sec (Fig.…”

“…The influence of medium failure on the impact character was considered in [56,62] by numerical methods. It was found in [62] that a single steel sphere is completely decelerated in an aluminum target at a depth of 12 mm under the examined impact conditions (h = 15 mm, d 0 = 5 mm, and U 0 = 1300 m/sec) if the medium ahead of the sphere does not lose its strength and continuity.…”

“…In the experiments of [56] performed by the scheme of [36] with a HE charge of thickness ∆ = 4 cm, nine steel spheres of diameter d 0 = 5 mm were accelerated, and their impact on Duralumin (D16-T) targets of thickness h = 15 and 100 mm was examined. A pulsed X-ray setup [60] revealed a leading group of spheres (4-5 spheres) moving with a velocity U 0 = (1400±100) m/sec and a group of retarded spheres moving with a velocity U 0 ≈ 1100 m/sec.…”

“…1 is reached in the scheme [36] of acceleration of solid impactors (steel spheres) by planar solid HE charge explosion products expanding in the channel of an evacuated shock tube. Two-dimensional numerical computations [56] performed by Mel'tsas and Portnyagina by Godunov's method [59] showed that this scheme allows one to generate fluxes of steel spheres moving with velocities from 1100 to 2400 m/sec, depending on the HE charge thickness (∆ = 4-9 cm) and on the sphere diameter (d 0 = 2-6 mm). These computations employ the above-given semi-empirical equation of state of explosion products (see Sec.…”