Accession Number : ADA305673

Title :   Relation of Ultrasonic Energy Loss Factors and Constituent Properties in Unidirectional Composites.

Descriptive Note : Final rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Williams, James H., Jr. ; Lee, Samson S. ; Nayeb-Hashemi, Hamid

PDF Url : ADA305673

Report Date : DEC 1979

Pagination or Media Count : 29

Abstract : A model is developed relating composite constituents properties with ultrasonic energy loss factors for longitudinal waves propagating in the principal directions of a unidirectional graphite/epoxy fiber composite. All the constituents are assumed to behave as linear viscoelastic materials with energy dissipation properties defined by loss factors. It is found that by introducing a new constituent called the interface material, the composite and constituent properties can be brought into consistency with simple series and parallel models. An expression relating the composite loss factors to the loss factors of the constituents is derived and its coefficients are evaluated. (MM)

Descriptors :   *GRAPHITE EPOXY COMPOSITES, TENSILE STRENGTH, NONDESTRUCTIVE TESTING, COMPOSITE MATERIALS, LAMINATES, ACOUSTIC WAVES, VISCOELASTICITY, FIBER REINFORCED COMPOSITES, DAMPING, DISSIPATION, ENERGY TRANSFER, ULTRASONICS, WAVE PROPAGATION, FATIGUE(MECHANICS), ACOUSTIC ATTENUATION, PARALLEL ORIENTATION, ULTRASONIC TESTS, UNIDIRECTIONAL, STRUCTURAL INTEGRITY.

Subject Categories : Laminates and Composite Materials
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE