| Issue |
EPJ Web of Conferences
Volume 26, 2012
DYMAT 2012 - 10th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
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|---|---|---|
| Article Number | 02005 | |
| Number of page(s) | 6 | |
| Section | Microstructural Effects | |
| DOI | https://doi.org/10.1051/epjconf/20122602005 | |
| Published online | 31 August 2012 | |
https://doi.org/10.1051/epjconf/20122602005
Mechanical and microstructural characterization of a HMX-based pressed explosive: Effects of combined high pressure and strain rate
1 CEA, DAM, Le Ripault, 37260 Monts, France
2 Sciences et Applications, 218 Bd. Albert 1 er, 33000 Bordeaux, France
The paper presents a study of the combined effects of strain rate and confining pressure on the behaviour and microstructure evolutions of a HMX-based explosive. Hopkinson bar compression experiments are carried-out on samples confined with a brass sleeve. The latter is instrumented in order to determine the confining pressure on the explosive sample, directly function of the sleeve thickness and yield strength. A sample confined at 75 MPa and deformed at 250s−1 is recovered, cross-sectioned and studied using optical microscopy. Distributed microplasticity and microcracking appear similar to those induced by confined quasi-static experiments, indicating that stress triaxiality is the most important loading parameter. The sample also displays a large shear macrocrack, resulting from the formation of an adiabatic shear band. Shear banding seems to proceed by strong plastic strain gradients, followed by dynamic re-crystallization. Further strong thermal effects are observed, resulting in local reactive melting.
© Owned by the authors, published by EDP Sciences, 2012