The force-field derivation and application of explosive/additive interfaces

Abstract

The inter-molecular force-field across RDX/(paraffin, fluoropolymer) interfaces are derived from first-principles calculated energies under the GGA+vdW functional. Based on the force-field, the polycrystal structures of mixture explosives are obtained, and a set of thermodynamic properties are calculated, including the elastic constants, thermal expansion coefficient, heat capacity, isothermal curve and the Hugoniot curve. The results are in good agreement with the available experiments, and provide a reasonable prediction about the properties of plastic bonded explosives. We find that the thermal expansion coefficient of a multi-component explosive is not only determined by the properties of the components, but is also affected by the thermal stress at the explosive/additive interfaces.

Theoretical Study of the Interfacial Force-Field, Thermodynamic Property, and Heat Stress for Plastic Bonded Explosives

“…To do so, the TATB body is described by the Gee's force-field, 16 the RDX body is described by the Smith's force-field, 13,14 the graphite coating is described by the intralayer potential from Tersoff's work 20,21 and the interlayer potential from Kolmogorov's work, 22 the polymer coating is described by the COMPASS force-field, 18,19 and the interfaces are described by the potentials obtained in this work and our pervious researches. 28,30 The electrostatic energy is considered for RDX and TATB bodies only, and is calculated by direct summation with the cutoff radius of 15 Å. The simulation methods and results are introduced in order.…”

“…The force-fields of explosives and additives have attracted much attention in past decades: Smith’s group developed the force-fields of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) , and TATB; Gee reported another kind of force-field for TATB; Song obtained the force-field of RDX; Sun developed the COMPASS force-field for polymers; , Tersoff , and Kolmogorov obtained the intralayer and interlayer potentials for graphite; Goddard’s group developed the reactive force-field for explosives; − and we reported a set of potentials across the explosive/additive interfaces. − Based on the previous researches, four kinds of interfaces are investigated in present work: the TATB/(paraffin, fluoropolymer), RDX/TATB, RDX/graphite and fluoropolymer/graphite interfaces. The force-field to describe the composite system of TATB, RDX, graphite and polymer is completed.…”

Theoretical study of the interfacial force‐field and thermodynamic properties for HMX‐Estane mixture explosives

“…Goddard and coworkers developed the reactive force-field for explosives [14][15][16][17], and investigated the decomposition mechanism by molecular dynamics (MD). We derived a set of pair potentials for explosive/additive interfaces [18][19][20][21][22], including the (fluoropolymer, graphite)/(HMX, TATB, RDX) systems.…”