Modeling of cutting forces in helical milling of unidirectional CFRP considering carbon fiber fracture

Helical milling is applied to the machining of CFRP owing to its favorable characteristics such as low cutting forces and heat generation. However, the prediction of helical milling forces remains a problem in CFRP processing. In this study, a novel predictive cutting force model of helical milling for unidirectional CFRP was established. Based on the cutting parameters, the dynamic cutting angle for the fiber and the corresponding cutting states of the fiber during the cutting process were analyzed, and the number and length of cutting edges involved in cutting were calculated. Then, the cutting forces on the cutting-edge micro-element of the periphery edge and bottom cutting edge under two different cutting states were calculated by treating the fiber as an equivalent homogeneous material. The cutting force prediction model was obtained by taking this into consideration. Finally, the helical milling experiment for unidirectional CFRP was carried out. The results show that the model can effectively predict the cutting force.