О высокоскоростном проникании стержней из пористого материала

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С.В. Федоров, А.В. Бабкин, В.А. Велданов
30 ISSN 1812-3368. Вестник МГТУ им. Н.Э. Баумана. Сер. Естественные науки. 2016. № 5
HIGH-VELOCITY PENETRATION OF POROUS MATERIAL RODS
S.V. Fedorov
A.V. Babkin
V.A. Veldanov
N.A. Gladkov
S.V. Ladov
Bauman Moscow State Technical University, Moscow, Russian Federation
Abstract Keywords
In this article we study the influence of material porosity on pene-
trative action of the powder shaped-charge jets formed during the
explosive collapse of the liners pressed from metal powder. We
employed numerical modeling within a two-dimensional axisym-
metric problem of continuum mechanics. It allowed us to research
the features of elongated porous projectiles penetration into a steel
target in the hydrodynamic mode (interaction velocity is several
kilometers per second). We considered the compressible elastic-
plastic matter with the Tait’s barotropic equation of state as a
target material. The model for the behavior of porous projectile
material was based on the assumption that closing of micropores
in the porous matter happens at a zero pressure, so it behaves as
monolithic. We compared the numerical modeling results with the
prediction given by the hydrodynamic theory with the incompres-
sible liquid assumption. We established that penetration depth
of porous rods exceeds the value calculated on Lavrentiev's formu-
la. The analysis of interaction in numerical calculations allows to
assume that this deviation is connected with formation of the
attached shock wave near a surface of contact with a target in the
course of penetration (penetration process for the porous projec-
tile has supersonic character due to essential reduction of sound
speed in porous materials). Based on this assumption and consi-
dering penetration process, Lavrentiev’s liquid jets collision in this
article we offer a simple model of elongated porous projectile
penetration. Its mathematical description includes system of equa-
tions for the attached shock wave front in the projectile, continuity
conditions on the surface of projectile and target contact and Ber-
noulli's equation which connects state parameters on a contact
surface with the shock wave parameters and with parameters of the
target. This model for porous projectile penetration depth allowed
us to define the ratio containing the additional multiplier to the
original Lavrentiev's formula. The multiplier depends on material
porosity. The output of calculations with this ratio is in compliance
with the result of numerical modeling
High-velocity penetration,
powder shaped-charge jet,
hydrodynamic mode, elon-
gated projectile, porous
material, penetrative action,
steel target, attached shock
wave
REFERENCES
[1] Lavrent'ev M.A. Cumulative charge and principles of its operation. Uspekhi Mat. Nauk
[Russian Mathematical Surveys], 1957, vol. 12, no. 4, pp. 41–56 (in Russ.).