Machining performance optimization in drilling of GFRP composites: A utility theory (UT) based approach

In the 21st century, GFRP composites have been successfully substituted majority of the traditional engineering materials and widely used in manufacturing sectors. As there are a number of favorable properties associated with GFRP composites; but machining of GFRP is significantly different as compared to other engineering materials, because, GFRPs are non-homogeneous in nature (which consist of distinctly different phases), so that their machining operation is characterized by uncontrolled intermittent fiber fracture causing oscillating cutting forces and critical bending stresses, poor surface properties due to crushed fiber or resin pull out. For effective use of any machining process, it becomes important to find optimum parametric setting to achieve improved quality as well as increased productivity. In this present context, a case study on optimal machining parameters selection has been reported to ensure high productivity as well as satisfactory surface quality of machined glass fiber reinforced epoxy composites. Utility function based on Taguchi optimization approach has been proposed in this research. During GFRP drilling, fiber breakage, entry and exit delamination are encountered as the major issues leading to decrease in product quality and overall productivity of manufacturing processes and products. Taguchi L16, 4 level orthogonal array have been used to study the influence of various combinations of process parameters Present work aims to conduct a case experimental research on drilling of GFRP (epoxy) composites in order to select the most appropriate process parameter combination by utility theory based approach to ensure satisfactory process performance yields as well as hole quality.