An integrated approach of CCD-TOPSIS-RSM for optimizing the marine grade GFRP drilling process parameters

This article aims to optimize the drilling process parameters using an integrated approach of the central composite design (CCD), the technique for order of preference by similarity to ideal solution (TOPSIS) and response surface method (RSM) to reduce delamination in the marine grade glass fiber reinforced polyester (GFRP) drilling. Marine grade GFRP composite laminates of 6, 8 and 10 mm thickness were made using E-glass fiber and isophthalic resins. Drilling experiments were conducted using 10 mm high-speed steel (HSS) drills on the specimen as per the central composite design framework with a face center value of unity. The process parameters speed (600, 1050 and 1500 rpm) and feed (0.1, 0.3 and 0.5 mm/rev) were considered as the control variables along with the material thickness. TOPSIS technique is used to optimize the process control parameters: speed, feed and material thickness based on four output performance characteristics: thrust force, torque, entry delamination and exit delamination. Analysis of variance (ANOVA) with a 99% confidence interval is used to determine the significant main and interaction effects with the corresponding percentage contribution of the drilling parameters. The experimental results indicate feed to be the most influential factor in the drilling of marine grade glass fiber reinforced polyester composites contributing 70.38% to the variation in the overall performance index, represented by the TOPSIS grade (TG).