抄録
Numerical and experimental study of the ultrasonic reflection characteristics of porosity-containing CFRP laminates immersed in water was carried out. Using two different kinds of incident frequency, the influence of porosity on the bottom echo as well as the reflected waves from interlayer interfaces was investigated respectively. It was observed from the lower-frequency incidence (2.25 MHz) that the bottom echo was gradually attenuated with the increasing porosity fraction. On the other hand, it was found from the higher-frequency incidence (10 MHz) that the duration of the reverberation behind the surface echo, due to the reflection at different interlayer interfaces, was reduced with the increasing porosity fraction.
