Abstract:In the actual processing procedure, multi-step processing was commonly used to optimize the hole-making quality of carbon fiber-reinforced plastic (CFRP). However, there was still a lack of detailed analysis on the formation mechanism of the cutting surface in multi-step processing. To address this issue, this paper constructed a secondary cutting simulation model for four typical fiber orientations (θ = 0°, 45°, 90°, 135°), and explored the formation mechanism of the cutting surface and the evolution pattern of cutting damage during the secondary cutting process. The results show that with the increase of the spindle speed n, the secondary cutting force exhibits a significant downward trend; while an increase in the feed rate Vf leads to a significant rise in the secondary cutting force. Further analysis reveals that when the fiber orientation θ is 0°, the influence of the cutting surface damage from the first cutting on the second cutting is relatively small. However, when the fiber orientation θ is 45°, 90°or 135°, under the condition that the second cutting thickness is less than the depth of the fiber damage layer caused by the first cutting, the second cutting can effectively remove the damage layer generated by the first cutting without causing new fiber damage, thus significantly improving the quality of the cutting surface.