Sensitivity Analysis of GFRP Composite Drilling Parameters and Genetic Algorithm-Based Optimisation

In this article, a genetic algorithm (GA) is used for optimizing a metamodel of surface roughness (R_a ) in drilling glass-fibre reinforced plastic (GFRP) composites. A response surface methodology (RSM) based three levels (-1, 0, 1) design of experiments is used for developing the metamodel. Analysis of variance (ANOVA) is undertaken to determine the importance of each process parameter in the developed metamodel. Subsequently, after detailed metamodel adequacy checks, the insignificant terms are dropped to make the established metamodel more rigorous and make accurate predictions. A sensitivity analysis of the independent variables on the output response helps in determining the most influential parameters. It is observed that f is the most crucial parameter, followed by the t and D. The optimization results depict that the R_a increases as the f increases and a minor value of drill diameter is the most appropriate to attain minimum surface roughness. Finally, a robustness test of the predicted GA solution is carried out.

Effects of cutting temperature and process optimization in drilling of GFRP composites

The present work deals with temperature effects and parametric optimization in the drilling of continuous glass fiber reinforced epoxy composite. Drilling ability was examined operating a drilling system with different drill bits, feed rate, and spindle speed parameters. The investigation was performed by changing the tool and composite interface. Drilling experiments were carried out under the dry condition. Thrust force and drilling temperatures were measured using dynamometer and thermal camera. Peel-up and push-out delamination were evaluated using an image analyzing tool. Results show that the tribo-mechanical behavior of the drilling operation is affected at different levels by tool coating. This behavior is related to the intrinsic friction properties of coating nature. Response surface methodology was used in the evaluation of experiment results. The feed rate of 0.13 mm/rev, spindle speed of 2425 rpm and HSS-TiN drill bit are found as an optimum drilling parameters and drill type.

Simulative Estimation of Reaction Force and Drill Accuracy of CFRP Composites

The present work deals with the finite element simulation of drilling of fibre-reinforced composites. The simulation is done using commercially available software. Hashin failure criteria has been used to simulate the drilling process. Three dimensional drill model was created and Hashin failure is defined via VUMAT sub-routine. Three-dimensional Hashin failure have larger stress and strain analysis resolution. This research is focused on validating reaction force and accuracy of drill. Reaction force obtained in composite drilling simulation is compared with experimental data. The work is focused on reproducing the simulation of composite modelling and composite damage rather than theoretical explanation of composite material and mathematical model behind the simulation. Thus, laying the knowledge to simulate composite fibres failure.