Accession Number : ADA303927

Title :   Ultrasonic Attenuation and Velocity in AS/3501-6 Graphite/Epoxy Fiber Composite.

Descriptive Note : Contractor rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

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

PDF Url : ADA303927

Report Date : DEC 1979

Pagination or Media Count : 37

Abstract : The ultrasonic group velocity and attenuation were measured as a function of frequency for longitudinal and shear waves in the epoxy matrix (3501-6) and in the principal directions of the unidirectional graphite/epoxy composite (AS/3501-C). Tests were conducted in the frequency ranges 0.25 MFIz to 14 MHz and 0.5 MHz to 3 MHz for longitudinal and shear wave modes, respectively. While the attenuation increased with frequency for all wave modes, the group velocity was independent of frequency for all wave modes. The effects of pressure and couplant at the transducer-specimen interface were studied and it was found that for each transducer type there exists a frequency-dependent 'saturation pressure' corresponding to the maximum output signal amplitude. (MM)

Descriptors :   *ACOUSTIC WAVES, *FIBER REINFORCED COMPOSITES, *EPOXY RESINS, *GRAPHITE EPOXY COMPOSITES, *ULTRASONIC PROPERTIES, STRESS STRAIN RELATIONS, TENSILE STRENGTH, NONDESTRUCTIVE TESTING, LAMINATES, VISCOELASTICITY, MATRIX MATERIALS, WAVE PROPAGATION, ACOUSTIC ATTENUATION, ACOUSTIC VELOCITY, ACOUSTIC EMISSIONS, ULTRASONIC TESTS, SHEAR STRENGTH, POLYIMIDE PLASTICS.

Subject Categories : Laminates and Composite Materials
      Plastics
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE