Linear Stability of a Two-Phase Process Involving a Steadily Propagating Planar Phase Boundary in a Solid. Part 2. Thermomechanical Case

Abstract

This investigation is directed toward understanding the role of coupled mechanical and thermal effects in the linear stability of an isothermal antiplane shear motion which involves a single planar phase boundary in a non- elliptic thermoelastic material which has multiple elliptic phases. When the relevant process is static--so that the phase boundary does not move prior to the imposition of the disturbance--it is shown to be linearly stable. However, when the process involves a steadily propagating phase boundary it may be linearly unstable. Various conditions sufficient to guarantee the linear instability of the process are obtained. These conditions depend on the monotonicity of the kinetic response function--a constitutively supplied entity which relates the driving traction acting on a phase boundary to the local absolute temperature and the normal velocity of the phase boundary--and, in certain cases, on the spectrum of wave-numbers associated with the perturbation to which the process is subjected. Inertia is found to play an insignificant role in the qualitative features of the aforementioned sufficient conditions. It is shown, in particular, that instability can arise even when the normal velocity of the phase boundary is an increasing function of the driving traction if the temperature dependence in the kinetic response function is of a suitable nature. Significantly, the instability which is present in this setting occurs only in the long waves of the Fourier decomposition of the moving phase boundary, implying that the interface prefers to be highly wrinkled.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1991
Accession Number
ADA236541

Entities

People

  • Eliot Fried

Organizations

  • California Institute of Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Boundary Value Problems
  • Differential Equations
  • Dispersion Relations
  • Energy
  • Equations
  • Free Energy
  • Heat Energy
  • Heat Flux
  • Instability
  • Latent Heat
  • Materials
  • Partial Differential Equations
  • Perturbations
  • Phase Transformations
  • Shear Stresses
  • Thermodynamics
  • Traction

Readers

  • Calculus or Mathematical Analysis
  • Materials Science and Engineering.
  • Plasma Physics / Magnetohydrodynamics