Study and analysis of drilling parameters using TLBO algorithm on GFRP composites

The paper focuses on the cutting behavior of Glass Fiber Reinforced Polymer (GFRP) composites and GNP–GFRP composites that contain varying amounts of Graphene Nano Platelets (GNP). GFRP composites are increasingly being used in a variety of industrial applications due to their excellent mechanical properties, such as high strength, stiffness, and low weight. However, their machining and cutting behavior can be challenging due to the presence of the reinforcing fibers. Therefore, the study aims to investigate the machining behavior of GFRP composites and the effect of adding GNP on their cutting behavior. The effect of different parameters such as cutting speed, feed rate and reinforcement rate on cutting forces and delamination factor is investigated. In addition, the tensile strength and fatigue behavior of the composite materials with the best and worst delamination factors were also determined. Addition of up to 0.2 wt.% of GNP to GFRP composites resulted in an increase in cutting forces and delamination factor when drilling GFRP composites. While the cutting force and delamination factor decreased with the increase in cutting speed, the cutting force and delamination factor increased with the increase in the feed rate. Analysis of variance (ANOVA) was performed to determine the effects of drilling parameters and reinforcement ratio on cutting force and delamination factor according to full factorial experimental design. The most efficient factor on the cutting forces is found to be feed rate (84.97%), followed by the reinforced rate (6.48%) and cutting speed (6.13%). The most efficient factor on the delamination factor is determined to be feed rate for (44.49%), followed by the reinforced rate (29.20%) and cutting speed (21.73%).

In this study, custom-fabricated multiwalled carbon nanotube (MWCNT)-reinforced and unreinforced glass fiber-reinforced polymer (GFRP) composites were used. These composites were manufactured via the vacuum-assisted resin transfer molding technique to ensure high-quality, consistent material properties. The study investigates the effects of MWCNT reinforcement ratios, cutting speeds, and feed rates on the drilling performance of GFRP composites. Key processing indicators such as surface roughness (SR), delamination, and thrust force were evaluated. A full factorial design comprising 27 experimental runs was employed. Variance analysis (ANOVA) and the Taguchi method were used for single-response optimization, revealing that the MWCNT reinforcement ratio had the greatest effect on delamination, while feed rate predominantly influenced thrust force. Cutting speed and feed rate were both found to significantly affect SR. For multiobjective optimization, the Criteria Importance Through Intercriteria Correlation-based weighting method was integrated with the Vlse Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) approach. The optimal parameters identified through this methodology were further refined using Taguchi signal-to-noise ratio analysis. According to the VIKOR analysis, feed rate emerged as the most influential factor, with a contribution ratio of 28.48%. The optimal drilling parameters correspond to Experiment No. 10, which involved a 0.5% MWCNT reinforcement ratio, a cutting speed of 25 m/min and a feed rate of 0.10 mm/rev (A 2 B 1 C 1 ). Under these conditions, the delamination factor (D₀) was 1.234, thrust force (F) was 82.03 N, and SR (Ra) was 1.575 µm. This integrated methodology provides a robust framework for optimizing drilling parameters in nanocomposite materials.

In this work, the research efforts have been made to investigate the effect of important drilling parameters such as spindle speed and feed rate on effectiveness of process and quality of holes during drilling of difficult-to-machine Al/SiC metal matrix composite using diamond-coated cemented carbide tool. Thrust force, hole diameter, delamination factor, surface roughness, tool wear, and chip analysis of the drilled holes were investigated at different spindle speeds (3000–9000 rpm) as well as feed rates (0.05–0.2 mm/rev), respectively. The outcomes of this study reveal that thrust force varies directly with the feed rate, but inversely with the spindle speed. Both the hole diameter and the delamination factor shows a rough proportionality with the feed rate, although the rates of variation are slow at the high spindle speed combined with a high feed rate. Similarly, the hole surface roughness increases with the feed rate, while the moderate spindle speeds produce better surface roughness. Smaller chips were found for all spindle speed. Adhesive and abrasive wear mechanisms are prominent on drill bit and drill wear occurs on both drill tip and secondary cutting edge. Drilling at moderate spindle speeds of 5000 rpm and 7000 rpm is the most suitable for the hole drilling in the Al/SiC metal matrix composites.

Glass fiber reinforced polymer (GFRP)-stainless steel stacks used in the aircraft structural components. The assembly process of this components requires mechanical joining using bolt and nut. The conventional drilling process is commonly used for producing hole to position the bolt correctly. Drilling is the complex machining process due to the variation in geometrical chance along the cutting edge. Thrust force and hole surface roughness are responses that used to evaluate the performance of drilling process. The quality characteristic of these responses are “smaller-is-better.” The aim of this experiment is to identify the combination of process parameters for achieving required multiple performance characteristics in drilling process of GFRP-stainless steel stacks materials. The three important process parameters,i.e., point angle, spindle speed, and feed rate were used as input parameters. Point angle was set at two different levels, while the other two were set at three different levels. Hence, a 2 × 3 × 3 full factorial was used as design experiments. The experiments were replicated two times. The optimization was conducted by using the combination of backpropagation neural network method and genetic algorithm method. The architecture of developed BPNN network had 3 input layers, 1 hidden layers with 8 neurons and 2 output layers. The activation functions of the hidden layer, the output layer and the network training were tansig, purelin and trainlm respectively. The minimum thrust force and hole surface roughness could be obtained by using point angle, spindle speed and feed rate of 118°, 2380 rpm, 61 mm/min respectively.

Natural fiber-reinforced composites have gained significant attention in engineering applications due to their sustainability, lightweight nature, and mechanical properties. However, machining these materials, particularly drilling, presents challenges such as delamination, fiber pull-out, and surface roughness, which impact component integrity. Limited research exists on optimizing drilling parameters for Spanish cherry fiber-reinforced hybrid composites to minimize machining defects. This study aims to optimize drilling parameters—drill bit diameter, spindle speed, and feed rate—using the Taguchi L27 approach to enhance machining performance. The composite was fabricated using Spanish cherry fiber, vetiver fiber, and coir pith in a polyester resin matrix through compression molding. Experimental trials analyzed the effects of process parameters on thrust force (TF) and surface roughness (SR), supported by ANOVA and regression analysis. Results indicate that spindle speed has a significant influence on TF and SR, followed by drill bit diameter and feed rate. The optimal setting (8 mm drill bit, 1480 rpm spindle speed, 160 mm/min feed rate) achieved minimal TF (3.82 kgf) and SR (8.76 µm). Water absorption increased with exposure time, with a maximum rate of 7.58% at 192 hours. These findings provide insights for improving composite machining and enhancing structural integrity. Future research should explore the effects of tool wear and alternative machining strategies.

PurposeThe purpose of this paper is to optimise the process parameters, namely, fibre orientation angle, helix angle, spindle speed, and feed rate in milling of glass fibre-reinforced plastic (GFRP) composites using grey relational analysis (GRA) and desirability function analysis (DFA).Design/methodology/approachIn this work, experiments were carried out as per the Taguchi experimental design and an L27 orthogonal array was used to study the influence of various combinations of process parameters on surface roughness and delamination factor. As a dynamic approach, the multiple response optimisation was carried out using GRA and DFA for simultaneous evaluation. These two methods are best suited for multiple criteria evaluation and are also not much complicated.FindingsThe process parameters were found optimum at a fibre orientation angle of 15°, helix angle of 25°, spindle speed of 6,000 rpm, and a feed rate of 0.04 mm/rev. Analysis of variance was employed to classify the significant parameters affecting the responses. The results indicate that the fibre orientation angle is the most significant parameter preceded by helix angle, feed rate, and spindle speed for GFRP composites.Originality/valueAn attempt to optimise surface roughness and delamination factor together by combined approach of GRA and DFA has not been previously done.

This paper attempts to analyze the effect of various drilling parameters such as feed rate, spindle speed and vibration frequency on performance characteristics such as thrust force, effective stresses, temperature and chip morphology in conventional drilling (CD) and ultrasonic-assisted drilling (UAD) of Ti6A14V using three different point angle (140°, 120°, 90°) drill bits in order to optimize the chip breakability of Ti6A14V. The three different point angle drill bits are utilized to establish the finite element models (FEM) to simulate the drilling process with Lagrangian approach in DEFORM-3D software. The simulations are validated by the experimental findings and analytical data of thrust forces, and the percent errors in results range approximately between 3 and 7%. The results obtained prove that UAD can produce segmental discontinuous chip, lower thrust force, lower process temperature and lower effective stress. The point angle of 120° drill achieved the thinnest chip thickness and the excellent effects of chip breaking. The achieved results are assumed to help for the optimization of the drill tool geometries, drilling parameters and chip breakability.

Composites are now being used to replace traditional metallic structures in a variety of industries that including aerospace, aircraft, and military, that demand structural materials of high stiffness-to-weight and strength-to-weight ratios. This work is aimed at investigation on drilling process parameters of a hybrid composite. A hybrid composite is prepared with Epoxy as matrix with Jute and Glass fibre reinforced material. It is attempted to investigate the delamination tendency of hybrid composite along with optimization of drilling parameters. The two parameters considered are speed and feed rate. Each of this is considered at 3 levels. Response characteristics are thrust force, torque, delamination factor. L9 orthogonal array will be considered for experimentation. Standard Analysis is performed to discriminate significant and insignificant factors. Optimized process parameters are obtained for each of response characteristics. The objective is to optimize drilling process parameters of a hybrid compositeTaguchi’s L9 3-level orthogonal array was employed in this work. Entropy weighted multivariate loss function optimizes the multi-responses with a single desired response for drilled hybrid composites at the common factor level. Spindle speed and feed rate operate as control elements, the responses are dependent on torque, thrust force, and delamination. Medium spindle speeds with smaller feed rates enhance drilling success, according to the findings. The results also showed that spindle speed has a higher influence on the quality of holes drilled.

Influence of Thrust Force in Drilling of Glass Fiber Reinforced Polycarbonate (GFR/PC) Thermoplastic Matrix Composites Using Box-behnken Design

Multi characteristic optimization of high-speed machining of GFRP laminate by hybrid Taguchi desirability approach

Prediction of drilling induced delamination and circularity deviation in GFRP nanocomposites using deep neural network

Thrust and torque force analysis in the drilling of aramid fibre-reinforced composite laminates using RSM and MLPNN-GA

Simulation and optimization of machining parameters in drilling of titanium alloys

Aircraft manufacturing involves drilling of large number of holes, in which the joint can be critically affected by the quality of the hole. Effect of drill geometry on drilling of glass/epoxy laminates using twist, Zhirov and Multifaceted Drills (MFD), has been studied. The thrust force and hole quality were compared for each drill geometry. Zhirov drill cuts the hole with less force and best surface finish. MFD produces less delamination when compared with the other geometries. ANOVA was used to study the effect of drill geometries, spindle speed, and feed rate on thrust force, surface finish and delamination factor.

Glass fiber reinforced polymer (GFRP) composites have high sensitivity to UV radiation, temperature, and moisture, and these factors lead to the decrease of mechanical properties. This study attempts to modify unsaturated polyester (UP) and vinylester (VE) resins with nano zinc oxide (ZnO) and organo-montmorillonite (OMMT), in order to improve UV radiation resistance and hygrothermal resistance. The nano ZnO/OMMT modified UP and VE based GFRP composites were subjected to UV radiation and hygrothermal aging at 30 °C, 50 °C and 60 °C (95% RH) for 90 days. Mass loss, moisture uptake, color change, flexural properties and short-beam-shear test were investigated. In comparison to unmodified GFRP specimens, ZnO/OMMT modifying decreased the mass loss, the color change, saturation moisture uptake, and the coefficient of diffusion. After exposure in UV radiation for 90 days, the flexural strength and interlaminar shear strength of nano modified GFRP composites increased by 23.5% and 27.8% compared with those of the unmodified GFRP composites. Nano ZnO/OMMT modifying also increased the flexural strength and interlaminar shear strength by 26.5% and 27.2% in hygrothermal condition at 60 °C. Furthermore, based on the change of mechanical properties and Arrhenius rate model, a prediction model was proposed to predict the life of nano modified FRP composites.