Accession Number : AD0750504

Title :   A Continuum Theory for Wave Propagation in Laminated Composites. Case 2: Propagation Parallel to the Laminates.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF APPLIED MECHANICS AND ENGINEERING SCIENCES

Personal Author(s) : Hegeimer,G. A. ; Bache,T. C.

Report Date : JUL 1972

Pagination or Media Count : 35

Abstract : A continuum theory with microstructure for wave propagation in laminated composites, proposed in a previous work concerning normal propagation, is extended herein to the case of propagation parallel to the laminates. Model construction is based upon an asymptotic scheme in which dominant signal wavelengths are assumed large compared to typical composite microdimensions. A hierarchy of models is defined by the order of truncation of the obtained asymptotic sequence. To estimate accuracy, the phase velocity spectrum is investigated. As in the previous case, retention of all terms in the asymptotic sequence is found to yield the exact spectrum of Rytov. Spectral collation of the lowest order dispersive theory with exact first mode data gives excellent agreement. Based upon asymptotic expansions, a simplified first-order theory is also developed. Transient pulse data obtained from the latter exhibits good correlation with experimental results. Representative calculations of microcomponent velocity distributions and interface shear stress are carried out using the simplified theory. (Author-PL)

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

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE