Composite materials such as fiber-reinforced plastics (FRP) are increasingly employed in the aeronautical industry, where the reduction of aircraft weight is essential to meet environmental and cost requirements related to lower emissions and fuel consumption. Due to structural requirements, aeronautical assembly processes on FRP components are based on the wide use of mechanical joints such as rivets. As the latter require a former hole making process, drilling is extensively applied to FRP composites in the aeronautical industry. The main challenges in FRP composite drilling are related to rapid tool wear and damage generation which affects material integrity and surface quality, with particular reference to delamination damage generation. In this chapter, case studies of drilling of CFRP/CFRP stacks for aeronautical assembly are presented to investigate and discuss the influence of drilling parameters, tool type and geometry on tool wear development, hole quality and surface integrity, and the opportunity to implement advanced sensor monitoring procedures for tool condition monitoring based on the acquisition and processing of thrust force and torque signals.
Part of the book: Characterizations of Some Composite Materials