Prediction and Optimization of Quality of Drilled Holes During Magnetic Drilling Operation of Glass Fiber Reinforced Polymer Composite

Abstract

This study presents the results of an investigation of the use of Box Behnken design approach to plan the experiments for drilling GFRP composite under different magnetic conditions with an overall objective of optimizing the process to yield better surface quality. Response Surface methodology (RSM) has been adopted to express the output parameters (responses) that are decided by the input process parameters. RSM also quantifies the relationship between the variable input parameters and the corresponding output parameters. RSM designs allow us to estimate interaction and even the quadratic effects, and hence, give us an idea of the shape of the response surface we are investigating. Box-Behnken design is having the maximum efficiency for an experiment involving three factors and three levels; further, the number of experiments conducted for this is much lesser compared to a central composite design. The proposed Box-Behnken design requires 17 runs of experiment for data acquisition and modeling the response surface. Design expert software 6.8.0 was used to design the experiment and randomize the runs. A nonlinear model was developed and its adequacy was verified to predict the output values at nearly all conditions. Further the model was validated by performing experiments, taking three sets of random input values. The output parameters measured through experiments (actual) are in good match with the predicted values using the model. Using ‘Design-expert’ software, 3D plots were generated for the RSM evolved. Such plots explicitly give an idea of the dominating process variable over others and the order of dominance; further the plots exhibit the trend of variables’ interaction in the process. This work resulted in identifying the optimised set of drilling parameters for GFRP composite material using HSS twist drill to achieve better surface quality. This work gains significance in the sense with minimum number of experiments, reliable model has been generated, validated and further, the process has been optimised. The observations of effect of magnetic field lead to the conclusion that magnetic drilling improves the factors significantly.