The effect of fiber orientation on mechanical properties and machinability of GFRP composites by end milling using cutting force analysis

In recent years, glass fiber-reinforced polymer (GFRP) composite materials have become a viable alternative material for different engineering applications due to their superior/excellent properties. The strength of the composite is positively related to the orientation of the fiber material. However, the machinability is still a problem when components are manufactured using the GFRP composites due to their anisotropic properties. The aim of this analytical research paper is to investigate the influence of fiber orientation on the strength and machinability in slot milling of GFRP fabricated using the vacuum infusion method. The fiber orientations of 0 degrees/90 degrees and +/- 45 degrees are used for the fabrication of GFRP composite laminates. The experiments were conducted using an orthogonal array. Analysis of variance was employed to determine the influence of milling parameters such as cutting speed, transverse feed rate, and axial depth of cut (A.D.O.C.) for the surface finish (R-a), cutting force, and Machinability index (MI). The MI is calculated based on specific cutting pressure. The influence of fiber orientation on the cutting force and surface topography was analyzed. It was concluded that the cutting forces were significantly influenced by the fiber orientation and not affected by the machining parameters. The results revealed that the transverse feed rate was the primary influencing parameter responsible for the increase in MI (40 to 56%). The A.D.O.C. was accountable for the increase in cutting force (55 to 94%). Similarly, the cutting speed influenced R-a, which increased from 17 to 37%.