Monitoring the drilling process of carbon fibre laminates using acoustic emission

Abstract

This work aims to apply Acoustic Emission to monitor the drilling process in carbon fibre laminates. Continuous Acoustic Emission data is captured over the entire drilling process of a through hole. The use of continuous acoustic emission data acquisition allows the identification of lower frequency periodic temporal features related to the cutting process. A new approach to data analysis is presented that utilises an enveloping technique to study these periodic phenomena and show that they correlate to changes in cutting regime as tool wear advances and hole quality reduces. This analysis of Acoustic Emission data is supported by the measurement of tool temperature, thrust force and the assessment of hole quality. Results show that Acoustic Emission activity is correlated to changes in the cutting process, and a correlation between tool wear and Acoustic Emission is observed. This correlation has been confirmed by corresponding increases in thrust force and drill temperature, with a consequent decrease in the observed hole quality.