Elastic interfacial waves in discrete and continuous media.

Abstract

Phonon spectra of bicrystals with relaxed grain-boundary structure display a variety of localized modes including long-wavelength acoustic modes. Continuum solutions for localized waves that incorporate atomiclevel elastic properties of the interface via discontinuity relations agree well with the latter modes. In contrast, classical solutions that depend only on bulk elastic properties do not. This demonstrates that the distinct atomic structure of the interface is a controlling factor, and it is shown how local, atomic-level properties can be incorporated into continuum analyses of interfacial phenomena. Disciplines Applied Mechanics | Atomic, Molecular and Optical Physics | Condensed Matter Physics | Engineering | Materials Science and Engineering | Semiconductor and Optical Materials | Structural Materials This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/235 Elastic interfacial waves in discrete and continuous media E. S. Alber and J. L. Bassani Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104 V. Vitek and G. J. Wang Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 ~Received 30 May 1995! Phonon spectra of bicrystals with relaxed grain-boundary structure display a variety of localized modes including long-wavelength acoustic modes. Continuum solutions for localized waves that incorporate atomiclevel elastic properties of the interface via discontinuity relations agree well with the latter modes. In contrast, classical solutions that depend only on bulk elastic properties do not. This demonstrates that the distinct atomic structure of the interface is a controlling factor, and it is shown how local, atomic-level properties can be incorporated into continuum analyses of interfacial phenomena.