Drilling optimization of woven CFRP laminates under different tool wear conditions: a multi-objective design of experiments approach

The cutting tool geometry is known to be an influential factor on damage induced during drilling of composite materials. Conversely, the geometry of the tool is affected under multiple drilling cycles due to highly abrasive nature of fibers. Building on earlier reports, the aim of this work is to create a better understanding of cutting parameters on the quality of drilled woven carbon fiber reinforced polymer (CFRP) laminates, given different tool wear conditions. Namely, a full factorial design of experiments has been conducted to quantify the significance of each process parameter (cutting velocity, feed rate and tool point angle), as well as their interactions, on the generation of entry-and exist-delaminations as well as the thrust force for different tool types. Finally, using a response surface methodology, a multi-objective optimization strategy has been presented to select optimum ranges of design parameters that can minimize the aforementioned output variables collectively. Such knowledge may be useful to explore further improvements toward defect-free drilling of woven CFRP composites.