Optimization of Machining Parameters During Drilling of GFRP Composite

Glass fiber-reinforced plastic (GFRP) composites are gaining importance day by day due to their excellent mechanical and anti-corrosive properties along with lightweight. Drilling of the GFRP is required during the assembly of the parts. During the drilling of composite laminate, the inhomogeneity, anisotropy, and vast difference between the properties of reinforcement and matrix lead to various undesirable phenomena like delamination, dimensional inaccuracy, and surface roughness. Optimization of the machining parameters during machining can reduce these problems. For the present research study, woven glass fabric reinforced in epoxy was made using the hand lay-up technique. Three input parameters: drill diameter, feed rate, and spindle speed at three levels, were taken. Taguchi’s method was used to design the experiment and optimize the process parameters. Taguchi L9 design was used for the design of the experiment. For the percentage contribution of machining parameter, analysis of variance (ANOVA) was done. Four output responses were taken: thrust force, surface roughness, peel-up, and push-out delamination factors. Drill diameter was found to be the most significant parameter for thrust force and both delamination factors, followed by feed rate. In contrast, feed rate was the most significant parameter for surface roughness. In terms of thrust force, surface roughness, peel-up delamination factor, and push-out delamination factor, the drill diameter contributes 54.27%, 33.54%, 52.16%, and 52.69% respectively. Thrust force, surface roughness, peel-up, and push-out delamination factors are all affected by feed rate, with respective contributions of 41.37%, 49.05%, 42.50%, and 42.16% Spindle speed was the least affecting machining parameters for the taken output responses.