Robust Algorithms for Penetration Mechanics Problems

Abstract

We have investigated the differences in the performance of identical depleted uranium (DU) and tungsten heavy alloy (WHA) rods when deformed in pure torsion, plane strain compression, and during impact at normal incidence onto a smooth rigid block or a deformable steel target. The thermomechanical response of the material has been modeled by the Johnson Cook relation that accounts for strain and strain rate hardening of the material and its thermal softening. The effect of modeling the thermal softening by a power law rather than the affine function has also been delineated. It is found that shear bands form at a lower value of the nominal strain in the WHA rod as compared to that in the DU rod during torsion, plane strain compression and the Taylor impact test. However, in the penetration test, a propensity of shear bands form in the DU penetrator in the region abutting the target penetrator interface and also in the ejecta where the penetrator particles turn to flow backwards. Fewer shear bands form in the WHA rod and they are smeared out resulting in a uniformly deformed zone of intense plastic deformation. Numerical simulation of a ceramic rod impacting a WHA plate showed that at high speeds a ceramic rod will perforate a WHA plate.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1998
Accession Number
ADA344460

Entities

People

  • R. C. Batra

Organizations

  • Virginia Tech

Tags

Communities of Interest

  • Air Platforms
  • Weapons Technologies

DTIC Thesaurus Topics

  • Algorithms
  • Continuum Mechanics
  • Deformation (Mechanics)
  • Failure Mode And Effect Analysis
  • Finite Element Analysis
  • Impact Tests
  • Materials
  • Mechanical Phenomena
  • Mechanical Working
  • Mechanics
  • Plastic Deformation
  • Shear Bands
  • Shock Waves
  • Simulations
  • Strain Rate
  • Stress Strain Relations
  • Three Dimensional

Readers

  • Explosive Engineering.
  • Structural Dynamics.