Abstract—Fiber reinforced plastics have been widely used for manufacturing aircraft and spacecraft structural parts because of their particular mechanical and physical properties such as high strength to weight ratio and also stiffness. Drilling of these composite materials can be considered as a critical operation owing to their tendency to delaminate when subjected to mechanical stresses. With regard to the quality of machined component, the principal drawbacks are related to surface delamination, fiber / resin pull out and inadequate surface roughness of the hole wall. Among the defects caused by drilling, delamination appears to be the most critical. Delamination is responsible for the rejection of approximately 60% of the components produced in the aircraft industry (Khasabha, 2004). Therefore, it is very important to detect the delamination undergone by the composite material. This necessitates an online technique, which can be used to monitor and measure the delamination as it occurs. Acoustic emission (AE), an online monitoring tool, is ideally suited for this purpose. The work discusses the experimental investigations carried out on Glass Fiber reinforced plastic (GFRP) composite specimens in which the acquired AE data is analysed. AE waveform obtained during drilling of GFRP composites are analysed and presented. The results clearly indicate that AE parameters as well as AE waveforms can be used to identify the optimum cutting condition on drilling glass fiber reinforced composite laminate and also can be used for monitoring the drilling process.
Cite:Sudha J., Sampathkumar S. and Vijaya A, "AE Waveform Analysis of Delamination in GFRP Composite Materials during Drilling," International Journal of Engineering and Technology vol.1, no.1, pp. 63-66, 2009.