Ultrasonic Testing System of Fiber-Reinforced Composites and Wavelet-Based Echo Signal Processing

Fiber-reinforced composites are widely used in many fields for the advantages of high specific strength and high specific modulus, but they are more difficult to be tested by ultrasonic method than metal because of whose high acoustic attenuation. The paper introduces ultrasonic testing system designed in our laboratory, which is aiming at inspection of FRC. Ultrasonic echo from composites is non-stationary signal which contains a large quantity of noise. Wavelet transform was applied to process the signal and good results were achieved.