Accession Number : AD0736879

Title :   A Continuum Theory for Wave Propagation in Laminated Composites.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF THE AEROSPACE AND MECHANICAL ENGINEERING SCIENCES

Personal Author(s) : Hegemier,G. A. ; Nayfeh,Adnan H.

Report Date : SEP 1971

Pagination or Media Count : 36

Abstract : A continuum theory is developed for wave propagation normal to the layers of a laminated composite with elastic, periodic microstructure. Construction is based upon an asymptotic scheme in which dominant signal wave lengths are assumed large compared to typical composite micro-dimensions. A hierarchy of models are defined by the order of truncation of the asymptotic sequence obtained. To estimate system accuracy, the phase velocity spectrum is investigated. Retention of all terms in the asymptotic sequence is found to yield the exact spectrum of Rytov. Based upon spectral collation of the lowest order dispersive model, accuracy superior to several existing theories is observed. In addition, treatment of several transient pulse cases show good correlation with exact data. Finally, the lowest order dispersive theory is case in a standard mixture form. (Author)

Descriptors :   (*COMPOSITE MATERIALS, MECHANICAL WAVES), LAMINATES, WAVE PROPAGATION, ELASTIC PROPERTIES, STRESSES, DEFORMATION, BOUNDARY VALUE PROBLEMS, CONTINUUM MECHANICS

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE