Theoretical model of instantaneous milling force for CFRP milling with a ball-end milling cutter: Considering spatial dimension and temporal dimension discontinuity effects

Milling force is a crucial parameter that impacts the surface quality of weakly rigid, curved carbon fiber reinforced polymer (CFRP) components. However, the cutting edge of ball-end milling cutter suitable for curvature processing has different cutting conditions at any point in the spatial dimension. Further, the cutting force can only be generated within the effective cutting range, which causes the cutting force to be discontinuous in both spatial and temporal dimensions. The above problems greatly increase the difficulty of calculating the CFRP milling force. To address this issue, in this study, a novel theoretical prediction model of instantaneous milling force for the milling of CFRP component by a ball-end milling cutter is established considering the discontinuity effects in spatial and temporal dimensions. The theoretical model has a maximum peak error of less than 18% compared with the experimental results. The impacts of different cutting parameters on the milling force are further discussed, which indicates that lower feed speed, axial cutting depth, and higher spindle speed should be selected to reduce the cutting force. This model could be helpful to determine the cutting parameters and tool selection for the high-performance milling of curved CFRP parts with excellent processing quality.