Accession Number : ADA305938

Title :   Stress Wave Attenuation in Thin Structures by Ultrasonic Through-Transmission.

Descriptive Note : Contract rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

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

PDF Url : ADA305938

Report Date : JAN 1980

Pagination or Media Count : 34

Abstract : The steady-state amplitude of the output of an ultrasonic through-trans mission measurement is analyzed and the result is given in closed form. Provided that the product of the input and output transduction ratios; the specimen-transducer reflection coefficient; the specimen-transducer phase shift parameter; and the material phase velocity are known, this analysis gives a means for determining the through-thickness attenuation of an individual thin sample. Multiple stress wave reflections are taken into account and so signal echoes do not represent a difficulty. An example is presented for a graphite fiber epoxy composite (Hercules As/3501-6). Thus, the technique provides a direct method for continuous or intermittent monitoring of through-thickness attenuation of plate structures which may be subject to service structural degradation. (MM)

Descriptors :   *ACOUSTIC WAVES, *FIBER REINFORCED COMPOSITES, *STRESS WAVES, STEADY STATE, NONDESTRUCTIVE TESTING, DEGRADATION, DEFECTS(MATERIALS), ECHOES, WAVE PROPAGATION, TRANSDUCERS, ACOUSTIC ATTENUATION, AMPLITUDE, ULTRASONIC TESTS, ACOUSTIC REFLECTION, GRAPHITE EPOXY COMPOSITES, PHASE SHIFT, PHASE VELOCITY.

Subject Categories : Laminates and Composite Materials
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE