Application of acoustic emission in drilling of composite laminates

Acoustic emission (AE) technique was used to characterise drilling of compo site laminates. Uni-directional glass fibre reinforced plastic (GFRP) lamin ates consisting of 12-layers and 16-layers (0/90)(s) were drilled using a t wist drill and the generated AE was monitored. Results of the investigation s reveal that the complexion of the acoustic emission root mean square (AE- RMS) signal response changes from the drill entry to the exit thus giving a n overall understanding about the different events that take place during d rilling. Also, AE-RMS signal level increases with an increase in the applie d thrust and further reveals that it is possible to evaluate the drill indu ced damages in composites through AE signal characterisation. (C) 2000 Else vier Science Ltd. All rights reserved.