Delamination Prediction and Multi‐Objective Optimization in Ultrasonic Vibration‐Assisted Helical Milling ( UVHM ) of UHMWPE Composites

Ultrasonic vibration‐assisted helical milling (UVHM) of ultra‐high molecular weight polyethylene (UHMWPE) fiber composites was experimentally investigated. Single‐factor experiments showed that UVHM reduced the delamination ratio by 2.6%–7.3% compared with conventional helical milling, and an energy accumulation framework based on intermittent cutting was proposed to elucidate the suppression mechanism. A Box–Behnken design ( n = 5000–7000 r/min, ng = 50–70 r/min, ap = 0.10–0.20 mm/r) was then employed to establish a second‐order RSM delamination model (R2 = 0.9888), with pitch identified as the dominant factor (F = 329.39). An RSM‐GRA nested strategy was developed, incorporating the RSM‐predicted delamination ratio with measured surface roughness, axial force, and material removal rate into gray relational analysis using an L16 orthogonal array ( n = 5000–8000 r/min). A Monte Carlo simulation ( N = 10,000) confirmed 98.2% ranking stability. A confirmation experiment at the recommended optimum ( n = 8000 r/min, ng = 50 r/min, ap = 0.10 mm/r) yielded a gray relational grade of 0.7816, exceeding the L16 best, and the measured delamination ratio closely matched the RSM prediction (error = 3.0%), validating the nested strategy.