Calibration of macroscopic impact ignition model from simulation of shear band formation on the mesoscale

Yehuda Partom, Erez Hanina

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

3 Scopus citations

Abstract

Relying on test results in [1] we proposed in [2] a macroscopic impact ignition model in terms of the product PD (P=pressure, D=plastic deformation rate). Here we upgrade this model by taking into account the time duration to ignition for different PD levels. Our macroscopic impact ignition model is now based on, and calibrated from, 1D simulations of pure torsion on the mesoscale. We assume that impact ignition is invoked by shear localization and formation of shear bands. We denote by (PD)L the macroscopic shear localization threshold. When PD>(PD)L in a macroscopic cell, shear bands start to form there. The shear bands then develop and heat up towards the ignition temperature. We further assume that the time duration from localization to ignition h=tig-tL also depends on PD. Using 1D simulations of shear band formation in torsion, similar to [3], we calibrate 1) the plastic flow curve coefficient Aγ (see later) from the localization threshold (PD)L determined from tests; and 2) the delay to ignition h(PD). We can then use these in macroscopic hydrocode simulations. Our mesoscale simulations depend on a realistic strength model for explosives. This model employs the overstress approach to dynamic viscoplasticity [4], and its main feature here is the pressure dependence of its plastic flow curve coefficient.

Original languageEnglish
Title of host publicationShock Compression of Condensed Matter - 2017
Subtitle of host publicationProceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter
EditorsMarcus D. Knudson, Eric N. Brown, Ricky Chau, Timothy C. Germann, J. Matthew D. Lane, Jon H. Eggert
PublisherAmerican Institute of Physics Inc.
ISBN (Electronic)9780735416932
DOIs
StatePublished - 3 Jul 2018
Externally publishedYes
Event20th Biennial American Physical Society Conference on Shock Compression of Condensed Matter, SCCM 2017 - St. Louis, United States
Duration: 9 Jul 201714 Jul 2017

Publication series

NameAIP Conference Proceedings
Volume1979
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

Conference20th Biennial American Physical Society Conference on Shock Compression of Condensed Matter, SCCM 2017
Country/TerritoryUnited States
CitySt. Louis
Period9/07/1714/07/17

ASJC Scopus subject areas

  • General Physics and Astronomy

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