Depth of penetration of high-speed penetrator with including the effect
of mass abrasion
J. Zhao
a
, X.W. Chen
b
,
*
, F.N. Jin
a
,Y.Xu
a
a
Engineering Institute of Engineering Corps, PLA University of Science and Technology, Nanjing 210007, Jiangsu, China
b
Institute of Structural Mechanics, China Academy of Engineering Physics, Mianyang 621900, Sichuan, China
article info
Article history:
Received 19 May 2009
Received in revised form
25 March 2010
Accepted 30 March 2010
Available online 11 April 2010
Keywords:
Mass abrasion
Kinetic energy penetrator
Depth limit
Penetration
Concrete targets
abstract
Mass abrasion is observed on the nose of projectile when a projectile strikes concrete target at high
velocity. To evaluate the influence of the mass abrasion on the depth of penetration (DOP) limit, the
relationship between the nose factor of the residual projectile after abrasion and the initial impact
velocity is suggested according to the experimental data. Based on the dynamic cavity expansion theory,
with considering the effects of varying nose factor and mass of projectile, a modified model is proposed
to calculate the depth of penetration of kinetic energy penetrator. The model predicts that a theoretical
maximum DOP exists due to the mass abrasion of the projectile. The model is checked by the different
experimental data.
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
Earth penetration weapons (EPWs) are applicable for attacking
the underground targets protected by reinforced concrete and rocks.
The upper limit of the impact velocity for conventional EPW is lower
than 1000 m/s [4,19], and the projectile is always assumed as non-
deformable in analysis. Most previous published experimental
results and theoretical models on the penetration of concrete targets
are in that range. With the continuously enhancement of penetration
performance of EPW, more and more research are focused on higher
speed penetration than 1000 m/s. Forrestal et al. [8] and Frew et al.
[11] conducted six sets of penetration experiments into concrete and
grout targets with different CRH (Caliber-Radius-Head) projectiles,
respectively, in which the maximum velocities range from 1300 m/s
to 1500 m/s. Lianget al. [21] also conducted an experimental study on
deep penetration of concrete by reduced-scale projectiles and the
highest striking velocity is close to 1200 m/s. Wu et al. [24] conducted
non-normal high-speed penetration experiments into concrete
targets with striking velocities between 800 m/s and 1100 m/s.
Recently, Yang et al. [15] experimentally investigated the mass
abrasion, damage and failure of projectiles when the projectiles
penetrating into concrete at velocity between 800 m/s and 1500 m/s.
Serious mass abrasion and structural failure of projectiles as well
as dramatic drop of DOP have been observed in experiments when
the striking velocity is large enough for deep penetration into
concrete. It has been revealed that an upper limit exists for DOP
[4,8,9,15,22]. Aiming at different impact velocities and failure
mechanisms, Chen and Li [3,4] defined three regimes of penetration
mechanics, i.e., non-deformable projectile penetration, semi-
hydrodynamic penetration and hydrodynamic penetration, respec-
tively. By using the impact function I, a transition point was found
between the non-deformable penetration and the semi-hydrody-
namic penetration, and then the upper limit of DOP was determined.
With the research interests transferring from conventional EPW
(penetration velocity < 900 m/s) to advanced EPW (1000 m/
s < penetration velocity < 1500 m/s), the mass loss of KE (kinetic
energy) penetrator becomes unavoidable, which may change the
nose shape and geometry of the penetrator, and thus possibly
affects the penetration efficiency. This aspect already becomes
a focus topic among the international research communities
[1,2,6,16,17,23]. Local abrasion and melting on the projectiles’
surface have been surveyed in experiments by Forrestal et al. [8]
and Frew et al. [11]. The mass loss is localized in a thin film of
exterior surface of the projectile, such as the nose and shank. The
ogive-nose becomes blunt, and its mass loss is up to 7%. Silling and
Forrestal [23] found there existed a linear relation between the
mass abrasion and the initial kinetic energy of projectile and
assumed that the rate of mass abrasion on projectile surface was
*
Corresponding author.
E-mail address: chenxiaoweintu@yahoo.com (X.W. Chen).
Contents lists available at ScienceDirect
International Journal of Impact Engineering
journal homepage: www.elsevier.com/locate/ijimpeng
0734-743X/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.ijimpeng.2010.03.008
International Journal of Impact Engineering 37 (2010) 971e979