Sc. Wooh et al., REAL-TIME ULTRASONIC AND ACOUSTIC-EMISSION MONITORING OF DAMAGE IN GRAPHITE EPOXY LAMINATES/, Composites engineering, 5(12), 1995, pp. 1403-1412
Progressive failure of a crossply composite laminate under uniaxial te
nsion was characterized by correlating ultrasonic and acoustic emissio
n measurements with damage in real time. Both ultrasonic backscattered
energy and acoustic emission gave consistent results and proved to be
sensitive indicators of matrix cracking and other failure mechanisms.
The acoustic emission signals were analyzed by investigating the ampl
itude and count frequency and the corresponding applied strain. Loadin
g/unloading tests showed that no additional damage occurs upon reloadi
ng up to the previous peak load.