The development of an ultrasonic vibration hand-held pneumatic drill for hole-machining on CFRP composite materials

Carbon fiber reinforced plastic (CFRP) composite materials are widely adopted for manufacturing aircraft. In aircraft assembly process, millions of bolt and rivet holes need to be machined on site, and most of them are drilled by manual operations with hand-held pneumatic drill. It is well known that unstable operations easily are caused in manual operations, which results in serious defects on CFRP materials. These defects drastically reduce fatigue resistance of aircraft. To improve the quality of drilling holes, an ultrasonic vibration hand-held pneumatic drill is developed in this study. The structure of this device was designed, and its vibration mode was analyzed with finite element method. A real ultrasonic vibration hand-held drill was produced and its vibration performance was measured. Drilling experiments on CFRP materials are implemented. The results show that, with the developed hand-held drill device, the shakes of hand decrease by 35–43% and thrust forces decrease by 23%. The defects of matrix resin peel-off and delamination during drilling process are significantly reduced. This study provides a novel equipment for drilling hole on aircraft assembly site.