An Investigation into Inelasticity Accompanying High Velocity Impact and Penetration Problems

Abstract

The problems investigated in the project fall into three broad categories: (1) Modeling of twinning under high velocity impact (2) Constitutive equations for elasto-plastic response under large deformations with application to simple shear, and (3) variational approaches to the development of governing equations and boundary conditions for incorporating "lattice curvature effects" in plasticity with application to shear banding problems. Results and their significance: Using a novel "multiconfigurational" framework developed by us, we have developed models that account for deformation twinning under high velocity impact. The results show good agreement with experimental data. We found that the nonlinearity of the elastic response will lead to interesting softening behavior when the material undergoes simple shear deformations. We have developed a theory incorporating lattice curvature effects that can effectively simulate the formation of shear bands. We have also developed a new variational technique based on the maximization of the rate of energy dissipation that not only delivers the governing differential equations but also the accompanying boundary conditions. This work will allow for the development of computational codes that can delineate the relative influence of lattice curvature, twinning and strain softening on the formation of shear bands.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 2001
Accession Number
ADA415119

Entities

People

  • A. R. Srinivasa
  • H. R. Rajagopal

Organizations

  • Texas A&M University

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Boundaries
  • Constitutive Equations
  • Curvature
  • Differential Equations
  • Dissipation
  • Equations
  • Experimental Data
  • Geometry
  • Materials
  • Mathematics
  • Mechanics
  • Phase Transformations
  • Plastic Properties
  • Scientists
  • Shear Bands
  • Softening

Fields of Study

  • Engineering

Readers

  • Computational Modeling and Simulation
  • Materials Science and Engineering.
  • Structural Dynamics.