Volume 13, Issue 4, 2004

Frequency Analysis and Process Monitoring in Drilling of Composite Materials

D. Kim¹*  and M. Ramulu²

¹School of Engineering and Computer Science, Washington State University, Vancouver, WA 98686-9600 USA
Tel: +1-360-546-9081, Fax: +1-360-546-9438, Email: kimd@vancouver.wsu.edu
²Department of Mechanical Engineering Box 352600,University of Washington, Seattle, WA 98195 USA
Tel: +1-206-543-5349, Fax:+1-206-685-8047, Email: Ramulu@u.washington.edu

*(Author to whom correspondence should be addressed)

(Received 6/04; accepted 12/04)

Abstract

Drilling experiments were conducted using carbide and cryogenic treated carbide drills into carbon fiber-reinforced thermoplastic composites, namly Graphite/PIXA-M (PIXA-M) composites. Drilling force signals were collected from all conditions and analysed using fast Fourier transformations and autoregressive (AR) time series models. Power spectrums were used to examine the cutting characteristics in the drilling process. AR coefficients were used to distinguish the cutting signals of autoclaved and induction heated PIXA-M composites, and conventional and cryogenic treated carbide drills.

Keywords: Thermoplastic composites; Drilling; Frequency analysis; Hole quality; Surface textures