Laser ultrasonic investigation of the elastic properties of unidirectionalgraphite-epoxy composites

An ultrasonic method is proposed for the determination of the elastic const ants of orthotropic solids with a laser source of ultrasound and wide-band registration of acoustic pulses. The propagation of acoustic transients in unidirectional fiber-reinforced graphite-epoxy composites is investigated. The experimental data show that the model of orthotropic solids is valid fo r the description of the mechanical properties of these materials. The abse nce of frequency dispersion of the phase velocity in the spectral range of 1-15 MHz for every direction of propagation of ultrasound waves in the comp osite was confirmed. A complete set of elastic constants of unidirectional fiber-reinforced graphite-epoxy composites is calculated.