Analytical force modeling for drilling of carbon fiber-reinforced polymer: integrating cutting dynamics and uncut fiber

Abstract

Drilling carbon fiber-reinforced polymer (CFRP) presents unique challenges because of the intricacies of cutting motions, including uncut fiber, pull-up, pull-down, and delamination. This paper proposes an analytical force model for CFRP drilling that considers the complex interplay of cutting forces during orthogonal cutting. This study utilizes the Euler-Bernoulli beam theory to analyze the cutting process within the chipping region and introduces a three-region force model encompassing the chipping, pressing, and bouncing zones. The model incorporates material properties, tool geometry, and cutting conditions to predict cutting forces and uncut fiber length. Parametric studies explore the influence of feed rates, rotational speeds, and drill diameters on cutting forces. Experimental validation on CFRP sheets with different fiber orientations demonstrated the model's accuracy, with errors below 10% for cutting forces and 8% for uncut fiber length. The proposed model offers a comprehensive understanding of CFRP drilling forces, enabling effective optimization of cutting parameters and enhancing the prediction of drilling-induced delamination. This analytical approach holds promise for broader applications in multidirectional CFRP machining.