Theoretical Studies of Interactions Between TATB Molecules and the Origins of Anisotropic Thermal Expansion and Growth
TATB containing explosives tend to permanently expand as their temperatures are increased or thermally cycled, a phenomenon known as ''ratchet-growth.'' Several mechanisms as to the cause of the non-reversible growth have been proposed, and are taken up here using various different modeling techniques. High-level quantum chemistry calculations have been used in parameterization of a classical potential function suitable for atomistic simulations of TATB. The quantum-chemistry-based force field for TATB was validated by comparing condensed phase properties obtained from molecular dynamics simulations with available experimental data. No permanent growth was manifest at the molecular level. Dissipative particle dynamics simulations were carried out in order to study the geometric packing effects on the mesoscopic scale, similar to the scales representative of Ultrafine. No permanent growth was identified when only simple packing effects were considered in the TATB model. However, non-reversible growth was displayed when crystal fracture capabilities were incorporated in the model, suggesting that crystal fracture induced by the anisotropic volume expansion of TATB is the root cause for the permanent growth seen in TATB containing explosives.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15005301
- Report Number(s):
- UCRL-JC-146807; TRN: US200322%%365
- Resource Relation:
- Conference: 33rd International Annual Conference of Institut Chemische Technologie, Berghausen (DE), 06/25/2002--06/28/2002; Other Information: PBD: 28 Mar 2002
- Country of Publication:
- United States
- Language:
- English
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