Online Monitoring of Drilling-Induced Delamination of Composite Materials by Acoustic Emission

Drilling composite materials is one of the primary processes of manufacturing industrial structures. The ultimate goal towards on-line monitoring of composites drilling is in order to produce damage free high quality drilled holes. In the present investigation, the acoustic emission (AE) technique was applied for monitoring the drilling-induced delamination. Delamination is major damage mechanisms in glass fiber reinforced plastic (GFRP) laminates correlated with the thrust force during drilling process. By feature extraction of AE time domain, root mean square (RMS) is selected as the best parameter to monitor thrust force variations. The experimental results show that AE is very sensitive to the response of the drilling conditions.