Effect of tool vibration on chip formation and cutting forces in the machining of fiber-reinforced polymer composites

摘要

This article investigates the chip formation mechanism and its influence on cutting forces during the elliptic vibration-assisted (EVA) cutting of fiber-reinforced polymer composites. To clarify the effect of the vibration, systematic finite element and experimental studies were performed on both the EVA and the traditional cutting of unidirectional fiber-reinforced polymers with various fiber orientations. The key factors that govern the cutting forces have been taken into account, such as the depth of cut, feed rate, tool vibration frequency and amplitude. The study found that fiber orientation significantly affects the chip formation and cutting forces. Fiber fracture can happen either above or below the trimming path, but that above the path dominates chip formation. When a fiber orientation is less than 90 degrees, chipping is mainly through bending-induced fracture of fibers; when it is beyond 90 degrees, however, chipping is mostly by crushing the fracture of fibers. Compared with a traditional cutting process, the EVA cutting can minimize the fiber orientation effect through localized fiber fracture. A dimensional analysis was then performed to provide a quantitative prediction of the cutting forces.