Accession Number : ADA326055

Title :   Elastic Behavior of an Atomic Lattice Under Large Volumetric Strains: The Quasi-Harmonic Idealization.

Descriptive Note : Final rept. Jan-Mar 97,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Segletes, Steven B.

PDF Url : ADA326055

Report Date : MAY 1997

Pagination or Media Count : 58

Abstract : The implications of Segletes' recent equation of state are examined, when idealized to the condition defined as quasi-harmonicity. Results indicate that at large volumetric strains, a proportionality no longer holds, in general, between the volumetric and vibrational stiffnesses. The governing relation between these two stiffnesses is presented and is a function of the characteristic frequency of the lattice, alternately expressed in terms of the lattice spacing. It is further shown that the quasi-harmonic idealization of Segletes' equation will approach the harmonic approximation in the limit.

Descriptors :   *MOLECULAR VIBRATION, *QUANTUM THEORY, *HARMONICS, *ELASTIC PROPERTIES, APPROXIMATION(MATHEMATICS), EQUATIONS OF STATE, POISSON RATIO, SECONDARY WAVES, ANHARMONIC OSCILLATORS.

Subject Categories : Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE