An Experimental Investigation of the Crack Growth Phenomenon for Drilling of Fiber-Reinforced Composite Materials

An experimental study has been conducted to study the crack growth phenomenon that occurs while drilling fiber-reinforced composite materials (FRCM), specifically unidirectional (UD) carbon fiber/epoxy resin. It uses an experimental setup that exploits the technology of video to understand the complete crack growth phenomenon as the drill emerges from the exit side of the workpiece. Significant damage mechanisms are observed and defined, and correlations between the average exit drill forces and the crack tip position are shown. Instantaneous forces as they vary along the orientation of the cutting edges are identified in terms of their contribution to the crack propagation.