The study of CFRP variable feed drilling method based on sinusoidal curve

In order to reduce the delamination damage of carbon fiber–reinforced polymer (CFRP) drilling and improve the drilling quality, a variable feed drilling method based on sinusoidal curve is proposed. That means, when drilling at a distance of 1 mm from the hole exit, the feed rate of the drill would be reduced according to the rule of sinusoidal curve. The method is compared with the traditional feed drilling by experiment, and the influence of the variable feed drilling on thrust force, delamination factor, surface quality, and surface roughness of hole wall and exit hole wall morphology are analyzed. The results show that compared with constant-feed drilling, the variable-feed drilling based on sinusoidal curve reduces the thrust force near the hole exit and greatly improves the delamination factor, surface quality, and hole wall morphology at the exit. However, the influence on the hole wall roughness is not particularly obvious.