Initial Decomposition Mechanism of 3-Nitro-1,2,4-triazol-5-one (NTO) under Shock Loading: ReaxFF Parameterization and Molecular Dynamic Study

We report a reactive molecular dynamic (ReaxFF-MD) study using the newly parameterized ReaxFF-lg reactive force field to explore the initial decomposition mechanism of 3-Nitro-1,2,4-triazol-5-one (NTO) under shock loading (shock velocity >6 km/s). The new ReaxFF-lg parameters were trained from massive quantum mechanics data and experimental values, especially including the bond dissociation curves, valence angle bending curves, dihedral angle torsion curves, and unimolecular decomposition paths of 3-Nitro-1,2,4-triazol-5-one (NTO), 1,3,5-Trinitro-1,3,5-triazine (RDX), and 1,1-Diamino-2,2-dinitroethylene (FOX-7). The simulation results were obtained by analyzing the ReaxFF dynamic trajectories, which predicted the most frequent chain reactions that occurred before NTO decomposition was the unimolecular NTO merged into clusters ((C2H2O3N4)n). Then, the NTO dissociated from (C2H2O3N4)n and started to decompose. In addition, the paths of NO2 elimination and skeleton heterocycle cleavage were considered as the dominant initial decomposition mechanisms of NTO. A small amount of NTO dissociation was triggered by the intermolecular hydrogen transfer, instead of the intramolecular one. For α-NTO, the calculated equation of state was in excellent agreement with the experimental data. Moreover, the discontinuity slope of the shock-particle velocity equation was presented at a shock velocity of 4 km/s. However, the slope of the shock-particle velocity equation for β-NTO showed no discontinuity in the shock wave velocity range of 3–11 km/s. These studies showed that MD by using a suitable ReaxFF-lg parameter set, could provided detailed atomistic information to explain the shock-induced complex reaction mechanisms of energetic materials. With the ReaxFF-MD coupling MSST method and a cheap computational cost, one could also obtain the deformation behaviors and equation of states for energetic materials under conditions of extreme pressure.

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Instrumentation on Impact Shock Study of Polymers and Possibility of Non-Equilibrium Shock Hugoniot

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.1059 ◽

2010 ◽

Vol 638-642 ◽

pp. 1059-1064

Author(s):

Kunihito Nagayama ◽

Yasuhito Mori

Keyword(s):

Carbon Fiber ◽

Velocity Profile ◽

Dynamic Response ◽

Particle Velocity ◽

Energetic Materials ◽

Polymer Materials ◽

Space Applications ◽

Shock Response ◽

Shock Hugoniot ◽

Relaxation Structure

Polymer materials have widespread applications in various situations for structural materials by themselves as well as by combining with other materials such as carbon fiber. Some of them are also candidates for energetic materials in space applications.[1] Due to their general use, shock response of them has attracted attention for many researchers.[2-4] One of the striking characteristics of the dynamic response of them is that stress and/or particle velocity profile has a relaxation structure of s range.[5, 6]

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Measurement of the slope of shock velocity-particle velocity Hugoniot curve for polymers

10.1063/1.1303423 ◽

2000 ◽

Cited By ~ 4

Author(s):

Yasuhito Mori

Keyword(s):

Particle Velocity ◽

Shock Velocity ◽

Hugoniot Curve

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First-order particle velocity equations of decoupled P- and S-wavefields and their application in elastic reverse time migration

Geophysics ◽

10.1190/geo2020-0452.1 ◽

2021 ◽

pp. 1-78

Author(s):

Zhiyuan Li ◽

Youshan Liu ◽

Guanghe Liang ◽

Guoqiang Xue ◽

Runjie Wang

Keyword(s):

Particle Velocity ◽

Computational Cost ◽

Staggered Grid ◽

Additional Stress ◽

Reverse Time ◽

Reverse Time Migration ◽

Computational Accuracy ◽

First Order ◽

Time Migration ◽

Stress Variable

The separation of P- and S-wavefields is considered to be an effective approach for eliminating wave-mode cross-talk in elastic reverse-time migration. At present, the Helmholtz decomposition method is widely used for isotropic media. However, it tends to change the amplitudes and phases of the separated wavefields compared with the original wavefields. Other methods used to obtain pure P- and S-wavefields include the application of the elastic wave equations of the decoupled wavefields. To achieve a high computational accuracy, staggered-grid finite-difference (FD) schemes are usually used to numerically solve the equations by introducing an additional stress variable. However, the computational cost of this method is high because a conventional hybrid wavefield (P- and S-wavefields are mixed together) simulation must be created before the P- and S-wavefields can be calculated. We developed the first-order particle velocity equations to reduce the computational cost. The equations can describe four types of particle velocity wavefields: the vector P-wavefield, the scalar P-wavefield, the vector S-wavefield, and the vector S-wavefield rotated in the direction of the curl factor. Without introducing the stress variable, only the four types of particle velocity variables are used to construct the staggered-grid FD schemes, so the computational cost is reduced. We also present an algorithm to calculate the P and S propagation vectors using the four particle velocities, which is simpler than the Poynting vector. Finally, we applied the velocity equations and propagation vectors to elastic reverse-time migration and angle-domain common-image gather computations. These numerical examples illustrate the efficiency of the proposed methods.

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Hydrogen Transfer in Energetic Materials from ReaxFF and DFT Calculations

The Journal of Physical Chemistry A ◽

10.1021/acs.jpca.6b13088 ◽

2017 ◽

Vol 121 (16) ◽

pp. 3019-3027 ◽

Cited By ~ 6

Author(s):

Oleg V. Sergeev ◽

Alexey V. Yanilkin

Keyword(s):

Dft Calculations ◽

Energetic Materials ◽

Hydrogen Transfer

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Early Thermal Decay of Energetic Hydrogen- and Nitro-Free Furoxan Compounds: The Case of DNTF and BTF

Physical Chemistry Chemical Physics ◽

10.1039/d1cp02881b ◽

2021 ◽

Author(s):

Shuangfei Zhu ◽

Wei Yang ◽

Qiang Gan ◽

Nianshou Cheng ◽

Changgen Feng

Keyword(s):

Thermal Decomposition ◽

Energetic Materials ◽

Decomposition Mechanism ◽

Thermal Decomposition Mechanism ◽

Thermal Decay

Exploring the initial reactions of H-free and nitro-free energetic materials could enrich our understanding into the thermal decomposition mechanism of various energetic materials (EMs). In this work, two furoxan compounds,...

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Overview: High Speed Dynamics and Modelling as It Applies to Energetic Solids

MRS Proceedings ◽

10.1557/proc-296-173 ◽

1992 ◽

Vol 296 ◽

Author(s):

J. Covino ◽

S. A. Finnegan ◽

O. E. R Heimdahl ◽

A. J. Lindfors ◽

J. K. Pringle

Keyword(s):

Energetic Materials ◽

High Speed ◽

Shock Loading ◽

Dynamic Deformation ◽

Two Dimensional ◽

State Data ◽

Impact Modelling ◽

Shock Response ◽

Hazard Assessments ◽

Reaction Thresholds

AbstractThis paper discusses experimental techniques and modelling tools used to characterize energetic solids subjected to dynamic deformation and shock. Critical experiments have been designed to study shock response and impact sensitivity of energetic materials. For example, a simplified two dimensional experiment has been developed to study the critical phenomena involved in delayed detonation reactions (XDT). In addition, wedge tests are used to obtain equation-of-state data. Coupled with hydrocodes, these experiments give us an in-depth understanding of the response of energetic materials subjected to shock loading. A coupled methodology using both experimental and modelling tools is presented. Consisting of three parts, it addresses all possible responses to fragment impact. The three parts are: (1) Fragment impact modelling (hydrocodes and empirically based codes); (2) Experiments to obtain accurate data for predicting prompt detonation; and (3) Tests with planar rocket motor models to explore mechanisms related to bum reaction thresholds and degree of violence. This methodology is currently being used in weapon design and munitions hazard assessments.

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