Prediction of Probabilistic Detonation Threshold via Millimeter‐Scale Microstructure‐Explicit and Void‐Explicit Simulations

Abstract

We present an approach and relevant models for predicting the probabilistic shock‐to‐detonation transition (SDT) behavior and Pop plot (PP) of heterogeneous energetic materials (HEM) via mesoscopic microstructure‐explicit (ME) and void explicit (VE) simulations at the millimeter (mm) sample size scale. Although the framework here is general, the particular material considered in this paper is pressed Octahydro‐1,3,5,7‐tetranitro‐1,2,3,5‐tetrazocine (HMX). To systematically delineate the effects of material heterogeneities, four material cases are considered. These cases are homogeneous material, material with granular microstructure but no voids, homogeneous material with voids, and material with both granular microstructure and voids. Statistically equivalent microstructure sample sets (SEMSS) are generated and used. Eulerian hydrocode simulations explicitly resolve the material heterogeneities, voids, and the coupled mechanical‐thermal‐chemical processes. In particular, it is found that both microstructure and voids strongly influence the SDT behavior and PP. The effects of different combinations of microstructure heterogeneity and voids on the SDT process and PP are quantified and rank‐ordered. The overall framework uses the Mie–Grüneisen equation of state and a history variable reactive burn model (HVRB). A novel probabilistic representation for quantifying the PP is developed, allowing the calculation of (1) the probability of observing SDT at a given combination of shock pressure and run distance, (2) the run‐distance to detonation under a given combination of shock pressure and prescribed probability, and (3) the shock pressure required for achieving SDT at a given run distance with a prescribed probability. The results are in agreement with general trends in experimental data in the literature.

Modeling and Simulation of RDX Powder Thermo‐Mechanical Response to Drop Impact

“…Commercially‐based DEM techniques [25–28] are powerful for their computational practicality in modeling macroscale particulate flow behaviors governed by the elastic or rigid body collisions of thousands of highly mobile particles. However, powdered EM materials have been shown to behave as highly plastic particles under drop hammer dynamic loads [14–29]. Modeling those types of impacts require that the plasticity of the particles be considered in the numerical treatment.…”

“…Over the past thirty years, a significant number of numerical studies have been devoted to modeling the initiation of heterogeneous solid explosives and propellants [15–17]. These numerical methodologies now extend into modern multiscale computational techniques that are leveraged on large‐scale computational systems [18–22]. Solid phase FEA simulations cannot reflect the influential role of the phenomena that occur as the EM response becomes dominated by phase changes.…”

Computational Design of Three-Dimensional Multi-Constituent Material Microstructure Sets with Prescribed Statistical Constituent and Geometric Attributes

“…More details on how the 3D and 2D SEMSS designed using the capability (4) presented in this paper can allow the multiphysics ME and VE simulations, prediction of microscopic behaviors, and probabilistic UQ are given in Refs. [3,17,29,55].…”

“…So far, the need for uncertainty quantification (UQ) has not been systematically addressed in many physics-based simulations. The use of SEMSS provides an important avenue to address this need and the concept has mostly been used in 2D simulations [3,[18][19][20][21][22][23][24][25][26][27][28][29][30] over the past decade.…”

Deep learning for synthetic microstructure generation in a materials-by-design framework for heterogeneous energetic materials

“…The frontier in computational energetic materials research is to develop predictive multi-scale models to guide the design process of novel materials with tailored performance via microstructural control 12,13 . Predictive frameworks of energetic material response to loads are a matter of concerted current development by several groups worldwide [14][15][16][17][18][19][20] ; such capabilities are needed to establish structure-property-performance (S-P-P) linkages as necessary precursors to materials-by-design of heterogeneous materials 12,21,22 . The work presented previous approaches.…”