Numerical and Experimental Investigation of Thermal Damage in Drilling of CFRP Composites

Carbon fiber reinforced polymer (CFRP) composites are extensively used in aerospace applications due to their light weight and special strength. Drilling of holes is the most frequently used machining operation for CFRP composites. In the drilling process, heat conduction with the anisotropic thermal properties of CFRPs is a complex process that requires special considerations. In this study, a 3D finite element (FE) model is developed to predict the temperature fields in drilling of laminated composites, considering the unique features of CFRPs, i.e., the multi-ply structures and anisotropic thermal properties. The thermal energy is determined from the cutting forces and the cutting parameters. A novel methodology is proposed to determine the heat partition ratio between the CFRP and the drilling tool. It considers the tool speed and geometry, the material properties, as well as the tool coating. The predicted temperature and thermal damage are validated experimentally, which are in good agreement with the measurements.