Burr assessment of punched holes on Al/CFRP/Al-stacked panel by profile measurement technique

Abstract In the aircraft industry, high-quality holes produced without affecting the strength of the assembled panel are important. Drilling is used to produce holes on composite panel but is limited by many types of wear, which cause low-quality holes. Predicting the quality of holes is difficult, especially when a composite/metal stacked panel is used for supporting and reinforcing components. Considering that the two aformentioned materials behave differently, several types of defects on the holes can be generated, such as burr. In this work, we carried out experiments on carbon fiber-reinforced composite/aluminum stacked panels to investigate the effect of a few parameters on the quality of the produced holes. The composite specimens were prepared at various thicknesses, and different fiber types (glass, carbon, and hybrid) and orientations were then stacked in between AA7075 plates. The images of the punched holes were captured and analyzed to measure the burr height at the hole exit of the specimen using profile measurement technique. Results showed that the burr pattern largely depends on the thickness and fiber types with slight dependency on fiber orientation.