Image analysis for CFRP drilled hole quality assessment

The use of Carbon Fiber Reinforced Polymer (CFRP) laminates for structural aerospace applications is growing for their superior mechanical properties associated to very low material weight. Machining operations on CFRP laminates, with particular reference to mechanical drilling, are critical due to the likely occurrence of material damages such as delamination when the laminate is subjected to stress concentration. The aim of this work is to present an approach based on digital image analysis to measure relevant parameters representative of the hole quality, focusing the attention on the hole geometry, and the measurement of different indices related to peel-up and push-out delamination.