Microscopic mechanism based force prediction in orthogonal cutting of unidirectional CFRP

The usage of carbon-fiber-reinforced polymer (CFRP) composite keeps increasing in modern industries. However, the machining mechanism of CFRP, especially the microscopic machining mechanism, is not well understood yet. This paper aims to establish a force prediction model for orthogonal cutting of unidirectional CFRP (UD-CFRP) in microscale. The deflection of the representative volume element (RVE), composed of a single fiber and the surrounding matrix, is analyzed considering the effect of the surrounding materials based on the minimum potential energy principle (MPEP). The critical force in the cutting edge that causes fracture of the RVE is obtained according to the bending deflection expression of the RVE. In addition, by taking slipping, peeling, and bounding mechanism in three different deformation areas into consideration, a force prediction model of UD-CFRP orthogonal cutting is established for fiber orientation ranging from 0° to γ_α + 90°. Several experiments have been conducted, and the results comparison shows that the model, though approximately, has gotten acceptable agreement with the experimental results, which proves the effectiveness of the analysis method.