2017 Insensitive Munitions & Energetic Materials Technology Symposium
Double Tree by Hilton Portland, Portland, OR, USA, April 23-26, 2018
Effect of Insensitive HE on Shaped Charge Jets
Werner Arnold
1
, Thomas Hartmann
2
, Ernst Rottenkolber
2
1
MBDA-TDW Gesellschaft für verteidigungstechnische Wirksysteme mbH, Hagenauer
Forst, D-86529 Schrobenhausen, Germany,
2
NUMERICS GmbH, Mozartring 6, D-85238 Petershausen, Germany
Abstract
Two different trends can be observed in the warhead community: on the one hand the de-
mand for increased insensitive munition (IM) is still growing. This finally led to the replace-
ment of TNT-bonded charges by plastic bonded ones (PBX). Contrary to TNT, a standard
(inert) plastic binder cannot react within the very short times of a detonation front and thus
leads to an increased roughness of the detonation front. On the other hand, there is also a
demand for an increased performance of shaped charges with 10 calibers depth of penetra-
tion for Cu liners or even 12 calibers for Mo liners. This requires thin and usually not con-
stant wall thickness liners. The possible conflicts of these two objectives were investigated in
experimental studies, which are summarized in the present work.
1 Introduction
A few decades ago, shaped charges were typically filled with TNT-bonded explosives. Al-
ready at that time, it was tried to measure the roughness of the detonation front resulting
from the inhomogeneity of the explosive ([1] & [2]) and the question was raised if this rough-
ness has an impact on the performance of a shaped charge jet (SCJ). However, experi-
ments showed that the influence was only marginal (e.g. [2] & [3]) and only little further at-
tention was given to the topic.
The question re-emerged when the classical TNT bonded explosives were replaced by plas-
tic bonded explosives (PBX) to make the charges more insensitive [4]. While the TNT binder
was detonable and the detonation front could propagate with approximately the same veloci-
ty in the explosive and in the binder, this is not the case with the inert plastic binder. Conse-
quently, the use of PBX increases the roughness of the detonation front.
At the same time, the developers of shape charges are striving for higher performance by
the application of higher density liner materials and / or non-constant thickness liners – both
measures at least partly decreasing the liner thickness and thus making the shaped charges
(theoretically) more sensitive towards a rough detonation front. Facing these trends, the det-
onation front roughness became an issue again and an experimental program was launched
to investigate its effects on the liner material and to quantify its influence on a shaped charge
jet.
2 High Explosive Types
Three batches of the TDW PBX KS32 (HMX/HTPB 85/15, = 1.64 g/cm³) with different
HMX grain size distributions were manufactured:
Standard: bimodal with mean grain sizes of 30 µm (fine mode) and 500 µm
(coarse mode),
