Stress Concentrators and Rate Effects in Formation of Adiabatic Shear Bands

Abstract

This Final Technical Report covers the contract period from 7 Nov 96 to 6 Jan 98. A more detailed information on the progress of this Contract can be found in the previous Interim Reports. During the period under consideration the research has been continued on analyses of experimental results obtained via the Modified Double Shear experimental technique (MDS). This technique has been applied for VAR 4340 steel with the heat treatment to -50 HRC. In order to study the effect of stress concentrators in shear at different rates of loading four MDS geometries have been tested with different stress concentrators, from "standard" geometry to a very sharp notch. A wide loading rate spectrum has been covered, from quasi-static to impact (up to impact velocity ^ 100 m/s). Experiments confirmed that the adiabatic stress concentrators accelerate failure in shear. This mechanism leads to a decrease of the fragmentation energy when the impact velocity is increased. In parallel, the numerical studies for all four geometries have been performed using the FE code ABAQUS. Details of the numerical studies are given in the appendix to this Report. The numerical analyses have confirmed all observations from experiments.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1998
Accession Number
ADA338750

Entities

People

  • Janusz R. Klepaczko

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Adiabatic Conditions
  • Computer Programs
  • Elastic Waves
  • Equations
  • Failure Mode And Effect Analysis
  • Hardening
  • Materials
  • Materials Testing
  • Mechanics
  • Numerical Analysis
  • Plastic Deformation
  • Secondary Waves
  • Shear Bands
  • Shear Stresses
  • Strain Hardening
  • Stress Strain Relations
  • Wave Propagation

Readers

  • Materials Science (Mechanical Engineering).
  • Mechanical Engineering/Mechanics of Materials.
  • Technical Research and Report Writing.