GENERALIZED CONTINUUM FIELD REPRESENTATIONS FOR LATTICE VIBRATIONS,

Abstract

Various representations of lattice displacement fields in the harmonic approximation are discussed. A method for defining a continuous field whose properties are systematically related to the lattice fields is developed. Using this method the usual elastic continuum and couplestress continuum approximations at long waves appear as the leading terms in a generalized continuum description of the harmonic lattice. The magnitude of the couple-stress effects can be estimated from molecular vibration data; at macroscopic wave lengths the couple-stress effects will be negligible in normal solids. Another application is the generalization of the method of long waves; this leads to ''effective modulus'' equations for arbitrary points in the BZ that are not zero. Application to study of extended defects is indicated. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1964
Accession Number
AD0441306

Entities

People

  • James A. Krumhansl

Organizations

  • Cornell University

Tags

DTIC Thesaurus Topics

  • Crystal Lattice Vibrations
  • Crystal Lattices
  • Crystal Structure
  • Displacement
  • Equations
  • Vibration
  • Waves

Fields of Study

  • Physics

Readers

  • Plasma Physics / Magnetohydrodynamics
  • Structural Dynamics.
  • Theoretical Analysis.