Wear resistance and induced cutting damage of aeronautical FRP components obtained by machining

A cutting induced-damage process involving matrix cracking, fiber fracture and interlaminar delamination often occurs when machining composite materials. Compared to metals, relatively little research has been carried out in this topic. Generally, damage mechanisms in machining composites include four types of wear modes: transverse matrix cracking, fiber–matrix interface debonding, fiber rupture and inter-ply delamination. The surface quality plays an important role in the improvement of fatigue life and wear resistance of composite components. In the case of high speed machining composite materials, the surface quality of the finished product may be improved by modifying the machining parameters. Due to the complex nature of this process, we focus here on the effect of cutting parameters on surface damage of the machined component and thus wear resistance. The later has been predicted using dynamic explicit finite element method. In this investigation a progressive failure analysis has been adopted for analysing damage process within the fiber reinforced polymer (FRP) workpiece. After damage is detected, selective stiffness degradation is applied to the workpiece material. It has been shown in this study that matrix cracking and interface shearing occur first, followed by wear of fibers. The damage progression in the matrix and interface occurs in parallel directions to the fiber axis. A random growth of fiber fracture has been observed and mainly localized in a plane with a specific direction. The effect of fiber orientation on wear resistance of the composite structure and cutting induced damage process has been investigated. Damage progression was found to be strongly influenced by the fiber orientation of the FRP composite.