Characteristics of Acoustic Emission Wave Attenuation in Short Fiber Reinforced Plastics

Abstract
The attenuation coefficient (α) of acoustic emission (AE) waves was evalu ated for short glass fiber reinforced poly(ethylene terephthalate) (SGFR-PET) as a func tion of fiber volume fraction ( V f) using simulated AE waves. The coefficient α decreased with increasing Vfmore rapidly than expected from a simple linear relation between α and Vf. The effect of wave attenuation was taken into account in a quantitative analysis of the peak amplitude distribution of AE waves which were detected from each zone partitioned in a specimen gage portion. The amplitude distribution which was obtained by the zoning method was compensated for the attenuation loss stated above. The compensated ampli tude distribution was shown to be almost similar in every zone of the specimen. The com pensated amplitudes of AE waves became much larger as the specimen deformation pro ceeded. Consequently, the AE peak amplitude obtained from short fiber reinforced plastics was shown to be considerably influenced by the wave attenuation.