Title: Effect of void positioning on the detonation sensitivity of a heterogeneous energetic material

Abstract

We show although it is well-established that voids profoundly influence the initiation and reaction behaviors of heterogeneous energetic materials such as polymer-bonded explosives (PBX) and propellants, there has been little study of how void location in different constituents in the microstructures of such materials affect the macroscale behavior. Here, we use three-dimensional (3D) mesoscale simulations to study how void placement within the reactive grains versus the polymer binder influences the shock-to-detonation transition (SDT) in a polymer-bonded explosive. The material studied here has a microstructure comprised of 75% PETN (pentaerythritol tetranitrate) grains and 25% HTPB (hydroxyl-terminated polybutadiene) polymer binder by volume. Porosities up to 10% in the form of spherical voids distributed in both the grains and polymer are considered. An Arrhenius reactive burn relation is used to model the chemical kinetics of the PETN grains under shock loading, thereby resolving the heterogeneous detonation behavior of the PBX. The influence of void location on the shock initiation sensitivity of the material is quantitatively ranked by comparing the predicted run distance to detonation (RDD) for each sample. The analysis includes inherent quantification of uncertainties arising from the stochastic variations in the microstructure morphologies and void distributions by using statistically equivalent microstructure samplemore » sets (SEMSS), leading to probabilistic formulations for the RDD as a function of shock pressure. The calculations reveal that the location of voids in the composite microstructure significantly affects the RDD. Specifically, voids exclusively within the grains cause the PBX to be more sensitive (having shorter RDD) than voids in the polymer binder. Unique probabilistic relationships are derived to map the probability of observing RDD for each void location material case, allowing for prediction of initiation behavior anywhere in the shock pressure – RDD space. These findings agree with trends reported in the literature.« less

Authors:

Coffelt, Christopher ^[1]; Olsen, Daniel ^[1]; Miller, Christopher  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-0684-4381"

Zhou, Min  ^[1]

• Search DOE PAGES for author "Zhou, Min"
• Search DOE PAGES for ORCID "0000-0002-8993-5675"

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+ Show Author Affiliations

1. Georgia Institute of Technology, Atlanta, GA (United States)
2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Publication Date:

Tue Feb 08 00:00:00 EST 2022

Research Org.:

Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA); Defense Threat Reduction Agency (DTRA)

OSTI Identifier:

1860795

Alternate Identifier(s):

OSTI ID: 1843991

Report Number(s):

LLNL-JRNL-818186
Journal ID: ISSN 0021-8979; 1027612; TRN: US2305930

Grant/Contract Number:  

AC52-07NA27344; HDTRA1-18-1-0004; 727563

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Applied Physics

Additional Journal Information:

Journal Volume: 131; Journal Issue: 6; Journal ID: ISSN 0021-8979

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; 97 MATHEMATICS AND COMPUTING; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; shock waves; materials properties; stochastic processes; chemical kinetics and dynamics; energetic materials; porous media; explosives; polymers; polycrystalline material; crystallographic defects