Development of a longitudinal–torsional ultrasonic vibration-aided drilling system for drilling carbon fiber-reinforced polymer materials

This study aimed to explore the motion properties of longitudinal–torsional ultrasonic vibration-aided drilling, the feature of drilling dynamics, and an efficient path of implementing longitudinal–torsional component conversion. It also aimed to propose a spiral chute horn with high performance and low cost based on the propagation characteristics of ultrasonic waves. The finite element software ANSYS was used for modal analysis and the geometric parameters of helical flutes were achieved. The dynamics analysis of the longitudinal–torsional ultrasonic drilling system revealed that the ultrasonic vibration could improve the rigidity of the drill and that the components existed in longitudinal and torsional directions. Drilling the T300-12K/AG80 unidirectional carbon fiber-reinforced polymer using the longitudinal–torsional ultrasonic drilling system revealed that the results of theoretical analysis and numerical simulation were comparable. This drilling system could change the longitudinal–torsional ratio according to the geometrical parameters of the modal converter, improve the surface quality of the carbon fiber-reinforced polymer hole, and reduce the exit delamination.