An experimental and statistical study on the effect of drill geometries on force and hole quality in drilling of glass fibre reinforced plastic (original) (raw)
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The most effective way of achieving good quality holes while drilling fibre reinforced plastics is by reducing the thrust and torque. Drilling experiments were conducted with drill points, namely standard twist drill, Zhirov-point drill, and multifacet drill, using wide range of spindle speed, and feed rate to analyse thrust force, delamination and surface roughness. At high spindle speed, cutting force is less and the special geometry improves the quality of the hole further, especially Zhirov point drill. Multifacet drill is found better as far as the delamination value is concerned.
Drilling of Glass Fibre Reinforced Plastic
Advanced Materials Research, 2012
Nowadays composite materials are used in many industrial areas. The main application of these is the aircraft industry. Problematic points with machining of composite materials are tool wear, tool life, delamination and temperature during machining of polymer composite materials. Paper focuses on investigation of delamination at drilling of glass fibre reinforced composites. Experiments were planned on the base so called design of experiment - DOE. We observed the evolution of delamination at investigations, when we combined 4 different variables (vc, fz, tool, cooling system). We investigated the evolution of force relations, torques, dimensional and shape accuracy, considering on delamination. We processed results statistically, for processing we used software MINITAB and MATLAB. We summarized results in tables and graphs.
Glass fiber reinforced plastic (GFRP) composite materials are widely used industrial, aerospace, and automotive sector. Its have excellent properties such as high strength to weight ratio, higher fatigue limit high stiffness to weight ratio, corrosion resistance and design flexibility. Drilling is one of the major machining operations that are carried out on fiber reinforced metal composite materials to the need for components assembly. There are many problems encountered when drilling Glass fiber reinforced plastic (GFRP) composites. These problems include delaminating of the composite, poor surface roughness and hole deviation. In present experimental investigation analyse the effect of various machining parameters i.e. cutting speed, the feed rate, and the drill diameter on the quality of the drilled holes. Hole deviation of each hole is measured with help of digital vernier calliper. Taguhi's and ANOVA Technique have been employed to study the effect of the interactions between different drilling parameters on deviation of holes. After experiments suggests the optimal conditions for minimum hole deviation.
International Journal of Engineering Research and Technology (IJERT), 2015
https://www.ijert.org/experimental-investigation-of-thrust-force-in-drilling-of-glass-fiber-reinforced-plasticgfrp-composite-laminates https://www.ijert.org/research/experimental-investigation-of-thrust-force-in-drilling-of-glass-fiber-reinforced-plasticgfrp-composite-laminates-IJERTV4IS020693.pdf Fiber Reinforced Polymer (FRP) composite materials are finding increased applications in variety of engineering fields such as automotive, aeronautical, etc and subsequently, the accurate machining is need for the composites has increased enormously. The mechanism behind the machining of fiber reinforced polymer composite is quite different from the metals, and it brings about so many undesirable results, such as sub-surface layer with cracks and delaminating. Glass fiber reinforced polymer (GFRP) composites have been steadily replacing metals as a better choice in place of engineering materials for various applications. Drilling holes efficiently in order to minimize the waste and defects of GFRP, it is most essential to understand the machining behavior of GFRP. There is a need to turn to analytical and experimental approaches to fully understanding the machining process. This work aimed to make an experimental investigation on drilling behavior of the GFRP and also to optimize process parameters.
This paper presents the results of an experimental investigation into the effect of lubrication and the tool type on thrust force and torque during the drilling of unidirectional glass fiber-reinforced plastic (GFRP) laminates. It is well-known that the most effective way of achieving good quality of holes while drilling fiber-reinforced plastics (FRPs) is by reducing the thrust and torque. Therefore, this investigation was aimed at exploring the possibility of reducing the thrust force and torque by using the concept of trepanning. The design considerations and development methodology of trepanning tools and twist drills are discussed. The appropriate tool has been determined by using statistically planned experiments and analysis. Orthogonal arrays with analysis of means as well as analysis of variance have been used to assess individual factor and interaction effects and their significance levels. The investigations have revealed that the performance of the trepanning tool was superior to that of the twist drill in terms of thrust force, torque and hole quality, as well as the influence of lubrication conditions.
MATEC Web of Conferences, 2014
The demand for mechanical fastening in composite materials is increasing due to their potential in large assemblies, aerospace and automotive industries. In practice, small components are integrated into large assemblies drilling holes in composite materials. Drilling defect free holes in composite presents many challenges during part assembly and services. This study presents the effects of cutting parameters used for drilling holes in glass fiber reinforced polymeric (GFRP) composites and hybrid fiber reinforced polymeric (HFRP) composites. Both the composites plates of 3 mm thickness were fabricated using a hand lay-up technique for the purpose of evaluating the effects of parameters on the quality of drilled holes. The holes were drilled using a 5 mm solid carbide twist drill at different spindle speed and feed rate. The quality of holes was assessed with respect to damage factor (F d) and surface roughness (Ra) of the drilled holes. Results showed that the HFRP composite experienced lower damage factor (F d) as compared to GFRP composite at lowerfeedrate or spindle speed. Scanning electron microscopic (SEM) examination revealed that the occurrence of delamination, fiber pull-out and matrix cracking was accelerated in the drilled holes at high spindle speed and feed rate.
Drilling of woven glass fiber-reinforced plastic—an experimental and finite element study
The International Journal of Advanced Manufacturing Technology, 2011
The present research work aims at studying the failure of woven glass fiber reinforced epoxy polymer composite laminates by drilling. The drilling experiments are conducted by using three drill bits of different drill point geometries of industrial grade by selecting suitable cutting speed and feed rate values. The drill bits used are made of High Speed Steel (HSS) and Tungsten Carbide materials. The thrust force signals were recorded using a drill tool dynamometer. Stress analysis of the drilled composite laminates based on the thrust force values was conducted in order to predict the design safety by finite element modeling (FEM). Furthermore, failure of the composite laminates is examined theoretically and analytically by using Tsai-Wu failure criterion for predicting ply failure. The results showed that HSS 8 facet drill is not recommended for drilling woven composite laminates as it recorded the highest failure index for high thrust force values. The surfaces of the drilled composites have been examined through SEM micrographs.
Drilling of Glass Fibre Reinforced (GFRP) Epoxy Composite Materials- an Experimental Study
— Fiber reinforced polymer composites have gained substantial attention as engineering structural materials in automotive, marine and aircraft industry as well as in civil engineering applications. This is due to their outstanding mechanical properties, impact resistance, high durability and flexibility in design capabilities and light weight. However, the delamination and the unstable crack growths are inherent problems associated with these fabric reinforced composites. Damage of composite structures through delamination are unstable crack growth perhaps the most important aspects of mechanical behavior which limit the wide applications of these materials. Machining of composite materials is difficult to carry out due to the anisotropic and non-homogeneous structure of composites and to the high abrasiveness of their reinforcing constituents. This typically results in damage being introduced into the work piece and very rapid wear development in the cutting tool. Conventional machining processes such as turning, drilling or milling can be adapted to composite materials, provided proper tool design and operating conditions are maintained. The present work also describes the machining (drilling) of GFRP composites with the help of Step drill of three sets, with three different speeds. Further work has been carried out by immersion of GFRP composites in sea water for 8 hrs, 16 hrs and 24 hrs duration and performed drilling operation. Results revealed that 8-4 mm step drill showed better machining characteristic than the other two 12-8 mm and 10-6 mm step drills. The ZnS Filled GFRP composites had better performance than TiO2 filled GFRP Composites.
A Review Paper on Effects of Drilling on Glass Fiber Reinforced Plastic
Procedia Technology, 2014
Drilling is an important process for making and assembling components made from Glass Fiber Reinforced Plastic (GFRP). Various processes like conventional drilling, vibration assisted drilling and ultrasonic assisted drilling have been attempted in order to maintain the integrity of the material and obtain the necessary accuracy in drilling of GFRP. This paper attempts to review the influence of machining parameter on the delamination damage of GFRP during drilling. In conventional machining feed rate, tool material and cutting speed are the most influential factor on the delamination hence machining at higher speed, harder tool material and lower feed rate have lesser delamination of the GFRP. Vibration assisted drilling and Ultrasonic assisted drilling have lesser thrust and hence lesser delamination compared to conventional drilling, which indicates that both vibration assisted drilling and Ultrasonic assisted drilling are more appropriate for drilling of GFRP.