Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : September 11, 2022 - September 14, 2022
In this paper, Acoustic emissions by fiber breakage under tensile test of single fiber composites were analyzed using wavelet transformation. PAN-based and two types of pitch-based carbon fibers were used in this study. Surface treatments by acetone or ethanol were conducted. Two AE sensors were used for detecting AE waveforms and the time-frequency diagrams were obtained. Experimental results showed that three damage modes of fiber break (400kHz), interrace fracture (200kHz) and fiber pullout (800kHz) appeared during tests. It appeared that the high frequency component cannot be detected when the sensor located far from the AE source. From the results of frequency analysis, it was found that frequency of fiber breakage was not so affected by Young’s modulus of carbon fibers. It indicated that resonance of resin around a broken fiber governed frequency by fiber break. On the other hand, it was seemed that frequency by fiber break of the acetone-treated fiber was slightly less than the ethanol-treated fiber. It was considered that the interface fracture length affected the frequency.
