Study on thrust force and torque sensor signals in drilling of Al/CFRP stacks for aeronautical applications

Multi-material stack products made of carbon fibre reinforce polymers (CFRP) and light-weight metal alloys, such as aluminium alloys, are becoming increasingly employed for aerospace applications. When composite laminates are stacked with metal alloy sheets, the drilling process becomes more complex due to the diverse properties of the stacked materials which involve different wear mechanisms and different drilling parameters. In this framework, the aim of this paper is to investigate the drilling process of Al/CFRP stacks for aeronautical applications through an experimental testing campaign under different drilling conditions. In order to study the thrust force and torque generated during the drilling process, a multiple sensor system is employed for data acquisition, and an advanced methodology for sensor signal processing in the time and frequency domain is developed.