Novel Methods in Terminal Ballistics and Mechanochemistry of Damage: A Review of Developments at the US Army Research Laboratory, 2001-2007

Abstract

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The phenomenological mechanochemistry of damage and radial cracking

“…We call this paradigm the Phenomenological Mechanochemistry of Damage (PMD). The origin and early developments of this paradigm are presented in a recent report [10]. Early publications on PMD were deliberately simplified to make transparent the main object and drama of the PMD: It is the competition between the (macro-scale) elastic accumulated energy on one hand, and the (nano-scale) energy accumulated in the chemical bonds on the other hand.…”

The Mechanochemistry of Damage and Terminal Ballistics

“…We accept the following simplest model for the total chemical energy: . The general thermodynamic inequalities for damageable substances (Grinfeld [1][2][3]) would imply that the damageable substance with such a chemical energy function will always be unstable. It is definitely not what we want: we want the substance which is stable, at least, in the unloaded intact state.…”

“…Per Grinfeld [1], the possibility of different bulk instabilities is the heart of the broader PMD theory. In the "vanishing" kinetics regime though, no material destabilization is possible in the framework of this current engineering PMD.…”

“…A generalized framework for PMD was presented by Grinfeld [1]. In this paper, the general PMD framework is specialized for a one-dimensional analysis to show the instability in mechanics that leads to loss of symmetric cracking for purely symmetric configurations.…”

“…This is a system of two equations with two unknown functions , u x t and , x t . This is a special 1-D case of much more general 3-D system derived in [1][2][3]. For the energy density of the ePMD this system can be rewritten as follows…”