Development of a comprehensive delamination assessment factor and its evaluation with high-speed drilling of composite laminates using a twist drill

Composites are cutting edge engineering materials for modern high-technology products. Their heterogeneous structure entails processing defects uncommon with metallic parts. Drilling is a crucial manufacturing process to facilitate fastening and assembly of composite components. High-speed drilling especially is a promising technique to increase the productivity as well as the quality of the drilled hole. The severity of delamination damage around the drilled hole is a critical factor in the error-free performance of these parts in service. A new method to characterize the delamination induced by drilling with a comprehensive assessment factor called effective equivalent delamination factor is developed to overcome the limitations of other measures being used hitherto. The capability and appropriateness of effective equivalent delamination factor as a delamination assessment factor are verified from experimental results.