The Emergence and Propagation of a Phase Boundary in an Elastic Bar.

Abstract

This dissertation is concerned with the dynamical analysis of an elastic bar whose stress-strain relation is not monotonic. Sufficiently large applied loads then require the strain to jump from one ascending branch of the stress-strain curve to another such branch. For a special class of these materials, a nonlinear initial-boundary value problem in one-dimensional elasticity is considered for a semi-infinite bar whose end is subjected to either a monotonically increasing prescribed traction or a monotonically increasing prescribed displacement. If the stress at the end of the bar exceeds the value of the stress at any local maximum of the stress-strain curve a strain discontinuity or phase boundary emerges at the end of the bar and subsequently propagates into the interior. For classically smooth solutions away from the phase boundary, the problem is reducible to a pair of differential-delay equations for the two unknown functions of a single variable. The first of these two functions gives the location of the phase boundary, while the second characterizes the dynamical fields in the high-strain phase of material. Estimates for the various dynamical field quantities are given and a priori conditions are deduced which determine whether the phase boundary eventually becomes the leading disturbance.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1983
Accession Number
ADA132275

Entities

People

  • Thomas James Pence

Organizations

  • California Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Asymptotic Series
  • Boundary Value Problems
  • Classification
  • Differential Equations
  • Discontinuities
  • Elastic Properties
  • Elastic Waves
  • Equations
  • Geometry
  • Integral Equations
  • Materials
  • Mechanics
  • Partial Differential Equations
  • Phase Transformations
  • Stress Strain Relations
  • Stresses
  • Waves

Fields of Study

  • Mathematics

Readers

  • Calculus or Mathematical Analysis
  • Mechanical Engineering/Mechanics of Materials.