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Title: A Predictive Model of Fragmentation using Adaptive Mesh Refinement and a Hierarchical Material Model

A Predictive Model of Fragmentation using Adaptive Mesh Refinement and a Hierarchical Material Model Fragmentation is a fundamental material process that naturally spans spatial scales from microscopic to macroscopic. We developed a mathematical framework using an innovative combination of hierarchical material modeling (HMM) and adaptive mesh refinement (AMR) to connect the continuum to microstructural regimes. This framework has been implemented in a new multi-physics, multi-scale, 3D simulation code, NIF ALE-AMR. New multi-material volume fraction and interface reconstruction algorithms were developed for this new code, which is leading the world effort in hydrodynamic simulations that combine AMR with ALE (Arbitrary Lagrangian-Eulerian) techniques. The interface reconstruction algorithm is also used to produce fragments following material failure. In general, the material strength and failure models have history vector components that must be advected along with other properties of the mesh during remap stage of the ALE hydrodynamics. The fragmentation models are validated against an electromagnetically driven expanding ring experiment and dedicated laser-based fragmentation experiments conducted at the Jupiter Laser Facility. As part of the exit plan, the NIF ALE-AMR code was applied to a number of fragmentation problems of interest to the National Ignition Facility (NIF). One example shows the added benefit of multi-material ALE-AMR that relaxes the requirement that material boundaries must be along mesh boundaries.
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Publication Date:
OSTI Identifier:950085
Report Number(s):LLNL-TR-411072
TRN: US200910%%171
DOE Contract Number:W-7405-ENG-48
Resource Type:Technical Report
Data Type:
Research Org:Lawrence Livermore National Laboratory (LLNL), Livermore, CA
Sponsoring Org:USDOE
Country of Publication:United States
Language:English
Subject: 36 MATERIALS SCIENCE; 42 ENGINEERING; ALGORITHMS; FRAGMENTATION; HYDRODYNAMICS; LASERS; SIMULATION; US NATIONAL IGNITION FACILITY; VECTORS