Application of Broadband Laser-Ultrasonic Spectroscopy for Nondestructive Testing of the Porosity in Carbon Fiber Reinforced Plastics with Various Volume Contents of Carbon Fibers

The method of broadband laser-ultrasonic spectroscopy based on laser thermooptical excitation of broadband acoustic pulses is used to obtain the frequency dependences of the phase velocity of longitudinal acoustic waves in composite materials. The frequency dependences of the phase velocity in the 0.8–10 MHz spectral range are studied for samples of the unidirectional carbon fiber reinforced plastics with various volume contents of the matrix...