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

Abstract

Specific features of pulsed loading of objects during intense expansion of explosion products of solid explosives are considered. Parameters of the semi-empirical equation of state of explosion products in the density range that has not been adequately considered are given. Results of experimental investigations of reflection of unsteady shock waves from a rigid wall and their effect on thin targets are summarized. Processes that occur under moderate-intensity dynamic impacts on solid and porous media are described: multiple collisions of solids with rigid targets, shock-induced coalescence of nanodiamonds, and emission effects due to expansion of explosion products into an evacuated volume, air, and inert gas.

Asymptotic Models for Studying Kinetics of Formation of Compact Objects with Strong Internal Bonds

“…The mechanism of crystal growth resulted from consecutive connection of "small" seeds to a "large" particle described by Formula (45) provides by an order of magnitude larger sizes than the mechanism of large particle coalescence described by Formula (46). The calculated results agree with the given in [57] experimental bimodal distributions of polycrystalline diamond particles under consideration.…”

“…Shock-induced coalescence of detonation nanodiamonds of "water" synthesis under dynamic loading in recoverable ampoule is described in [53] [55]- [57]. Growth of particles is described by the following formulae obtained using the above laws (22), (23): …”

Effect of surface phenomena on target destruction by a multiple impact of solids

“…The collective action of macroscopic solids on targets was considered in many papers [2][3][4][5][6][7][8]. Various authors [5][6][7][8] performed experiments and established the facts of deeper penetration of a group of steel spheres with a diameter d = 5 mm into Duralumin targets, as compared with penetration of an individual sphere with a "moderate" impact velocity u = 1.2-1.4 km/sec, in which case the effects of compression and heating are comparatively weak, and the main role belongs to deformation (strength) processes.…”

“…The collective action of macroscopic solids on targets was considered in many papers [2][3][4][5][6][7][8]. Various authors [5][6][7][8] performed experiments and established the facts of deeper penetration of a group of steel spheres with a diameter d = 5 mm into Duralumin targets, as compared with penetration of an individual sphere with a "moderate" impact velocity u = 1.2-1.4 km/sec, in which case the effects of compression and heating are comparatively weak, and the main role belongs to deformation (strength) processes. In the present paper, we try to explain the effect found from the viewpoint of the commonly known concepts [9] of surface phenomena in solids in the course of their deformation and disintegration caused by an adsorptioninduced decrease in strength at the interface between the solid and liquid phases under tensile stresses.…”

“…In view of the idea [9] on adsorption-induced reduction of strength (Rebinder effect), the experimental facts [5][6][7][8] of melting of the target material, formation of spalls and cracks on hole and crater surfaces, and elevated effectiveness of penetration of a group of "interacting" projectiles testify that the examined process of a multiple impact of solids on targets may be affected by the contact of the solid phase with its own melt and a corresponding substantial decrease in free surface energy σ at the interface (and, correspondingly, the work of formation of a new surface). The accompanying decrease in strength (embrittlement) of the solid phase leads to initial acts of disintegration on material defects (dislocations, admixtures, grain boundaries, etc.).…”