Author
Timms, R
Purvis, R
Curtis, J
Journal title
26th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS 2017)
Last updated
2023-02-12T08:57:07.947+00:00
Abstract
Safety is of paramount importance in the handling, processing and storage of explosives. Mechanical insults resulting from low-speed impact, that crush and pinch an explosive, have been identified as a possible ignition source. However, modelling such an ignition mechanism numerically with hydrocodes proves to offer some considerable challenges. Here we develop a model for the pinching of an explosive cylinder between two flat plates which accounts for the effects of friction at the contact between the plates and the explosive. An ad hoc analytical method of the axial pinching of an explosive cylinder by two flat plates moving at constant speed is developed and discussed in [1]. In this formulation it is assumed that as the material is compressed it is in perfect plastic flow under adiabatic conditions. The explosive reaction is modelled using a simple Arrhenius Law. The heating of the explosive due to mechanical heating and self heating due to the reaction are calculated. In the analysis presented there is no treatment of friction at the contact region between the plate and explosive. As a result of this simplification the dissipation calculated is constant throughout the sample. This is contrast with experiments conducted at AWE in which non-uniform heating is observed [2]. Sherwood and Durban [3] investigated the squeezing of a non-reactive viscoplastic solid in the presence of friction. It is suggested that their paper may form a strong basis to explore frictional effects in the configuration posed in [1]. Here we adopt the approach taken in [3] to describe the mechanical behaviour of an explosive sample subject to axial compression, and then introduce a simple Arrhenius Law, as in [1], to model the reaction. The work presented allows us to investigate the effects of frictional heating during compression and arrive at an improved model of the so called Pinch Test.
Symplectic ID
922547
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Publication type
Conference Paper
Publication date
27 Jul 2017
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