Cross-scale modeling and process parameter optimization for drilling and milling of woven CF/PEEK composites

Marine woven Carbon Fiber Reinforced Poly Ether Ether Ketone (CF/PEEK) composites easily suffer delamination, hole-edge burrs and dimensional errors during drilling-milling, reducing structural service accuracy. This work establishes a thermo-mechanical coupled multiscale finite element model and optimizes machining parameters for this hole-making process. The mechanical performance and mesoscopic constitutive relation of woven CF/PEEK are characterized based on its actual woven structure. Corresponding drilling-milling experiments are performed to verify model reliability using thrust force, machining temperature field and hole-wall micro-morphology as evaluation indicators, and the evolutionary rule of hole-wall morphology is clarified. Numerical iterations under various process parameters reveal the coupled force-temperature response of specimens. Grey relational analysis is utilized to acquire optimal drilling-milling parameters. Results verify that the established cross-scale drilling and milling model precisely predicts thermo-mechanical damage evolution of woven CF/PEEK. The simulation-test deviation of steady milling thrust force is less than 3%, the maximum drilling thrust force error is approximately 6%, and steady temperature deviations for both processes are within 11%. Optimized parameters significantly suppress the initiation and propagation of machining defects, providing theoretical reference for high-precision hole fabrication of similar composite materials.