Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2025 (SCI-Expanded)
Delamination damage is one of the main problems that occur when mechanically drilling laminated composite structures. Various techniques have been used to lessen the damage caused by delamination. Utilizing a backup while drilling is one such technique. However, the impact of backup with various characteristics on the composite drilling process and related delamination has not been extensively studied. Thus, the study used experimental methods to investigate the drilling of carbon fiber-reinforced polymer (CFRP) material without support and with various types of support plates (wood, plastic, and aluminum). Five distinct feed rates and two spindle speeds were used in the tests, and the thrust force damage inside the hole and delamination at the hole exit were examined. The material of the chosen backup had a minimal effect on the thrust force magnitude. Using a support plate helped to decrease the cutting force within the parameters of the study. In every test configuration, the absence of a support plate resulted in the greatest damage and uncut fibers at the hole exits. A significant amount of borehole damage was observed after the composites were machined without the support plate.