ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

1pPA6. Harmonic generation measurements as a function of frequency in a carbon-fiber-epoxy-resin composite.

Paul Elmore

M. A. Breazeale

Natl. Ctr. for Physical Acoust., Univ. of Mississippi, University, MS 38677

Harmonic generation in a carbon-fiber-epoxy-resin composite has been measured as a function of frequency between 4.0 and 8.5 MHz. The amplitudes of both the fundamental and the generated second harmonics were measured absolutely with a capacitive receiver at room temperature. Phase velocities also were measured. Dispersion is seen in the conventional nonlinearity parameter, but not in the phase velocity. The composite sample is highly attenuative and may have additional nonlinear terms that are not yet accounted for theoretically. Since the conventional nonlinearity parameter is defined for a lossless solid, data interpertation is unclear at present.