Variations in Acoustic Emission Between Graphite- and Glass-Epoxy Composites

Abstract

This paper presents acoustic emission data for graphite- and glass-epoxy, and glass-chopped matt composites. This micro-earthquake-like wave phenomenon resulting from microstructural failure is noted to possess dif ferent characteristics depending upon the composite material being tested. Results of three point bending of specimens and cantilevered specimens with transverse saw cuts under monotonically increasing load indicate that matrix crazing and combined delamination and fiber breakage occur at lower and higher amplitude, respectively. Differences in behavior were also noted be tween these materials as the type of loading was varied.