Hybrid composite materials are the great potential for engineering material in many applications. Hybrid polymer composite material offers the designer to obtain the required properties in a controlled considerable extent by the choice of fibers and matrix. The properties are tailored in the material by selecting different kinds of fiber incorporated in the same resin matrix. In the present investigation, the mechanical properties of carbon and glass fibers reinforced epoxy hybrid composite were studied. The vacuum bagging technique was adopted for the fabrication of hybrid composite materials. The mechanical properties such as hardness, tensile strength, tensile modulus, ductility, and peak load of the hybrid composites were determined as per ASTM standards. The mechanical properties were improved as the fibers reinforcement content increased in the matrix material

Harish, G.

Jagannatha, T.D.

ePrints@Bangalore University

131Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015MECHANICAL PROPERTIES OF CARBON/GLASSFIBER REINFORCED EPOXY HYBRID POLYMERCOMPOSITEST D Jagannatha1* and G Harish1*Corresponding Author: T D Jagannatha, jagannathtd@gmail.comHybrid composite materials are the great potential for engineering material in many applications.Hybrid polymer composite material offers the designer to obtain the required properties in acontrolled considerable extent by the choice of fibers and matrix. The properties are tailored inthe material by selecting different kinds of fiber incorporated in the same resin matrix. In thepresent investigation, the mechanical properties of carbon and glass fibers reinforced epoxyhybrid composite were studied. The vacuum bagging technique was adopted for the fabricationof hybrid composite materials. The mechanical properties such as hardness, tensile strength,tensile modulus, ductility, and peak load of the hybrid composites were determined as per ASTMstandards. The mechanical properties were improved as the fibers reinforcement contentincreased in the matrix material.Keywords: BHN, Epoxy, Hybrid composite, Carbon/Glass fiber, Tensile strengthINTRODUCTIONNow a days, the composite engineers arefocusing on the development of new stronger,tougher, lightweight structural materialssupporting latest technologies and designconcepts for the complex shaped structureslike aircraft, automotive structures and largewind turbine blade structures (Gururaja et al.,2012). The development of compositematerials improves their performance basedon the reinforcement of two or more fibers in aISSN 2278 – 0149 www.ijmerr.comVol. 4, No. 2, April 2015© 2015 IJMERR. All Rights Reserved1 Department of Mechanical Engineering, UVCE, Bangalore University, Banagalore 560001, India.single polymeric matrix, which leads to theadvanced material system called hybridcomposites with a great diversity of materialproperties (Prabhakaran et al., 2012). This isa major challenge that can only be met throughan understanding of the relationships betweenmaterials architecture and mechanicalresponse. The positive or negative hybrideffect of selected mechanical property from therule of mixture behavior of carbon/carbon/epoxy and glass/carbon composites wereResearch Paper132Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015studied. None of the mechanical properties,excluding the fracture energies show signs ofa positive hybrid effect (Marom et al., 1978).Manders and Bader (1981) reported hybrideffect and failure strain enhancement of up to50% for the glass fiber/carbon fiber/epoxycomposite. The failure strain of the carbonphase increased as the relative proportion ofcarbon fiber was decreases and as the carbonfibers were more finely dispersed. Yerramalliand Waas (2003) have considered carbon/glass hybrid composite with an overall fibervolume fraction of 30%. Splitting and kinkingfailures were noted while loading the hybridlaminates under static and dynamic loadingrates. Zhang et al. (2012) studied themechanical behavior of hybrid compositesmade of carbon/glass reinforcements and theprocessing method used is ‘wet lay-up’ whichis not a best practice for obtaining high qualitylaminates. An addition of hard reinforcementssuch as silicon carbide, alumina and titaniumcarbide improves hardness, strength and wearresistance of the composites (Amar Patnaiket al., 2009; and Chauhan et al., 2009). Theintroduction of a glass fiber into a polymermatrix produces a composite material thatresults in an attractive combination of physicaland mechanical properties which cannot beobtained with monolithic alloys (Schwartz,1984). Among the various useful polymermatrices, vinyl ester is typically characterizedby properties such as fluidity, corrosionresistance and high strength-weight ratio(Suresha et al., 2007). The advantages ofFiber-reinforced PMCs over traditionalmaterials include greater mechanical strength,lighter weight, better dimensional stability,higher dielectric strength and corrosionresistance and flexibility to improve thedesigns (Folkes, 1992). The effectiveness ofreinforcement essentially depends on theadhesion between matrix and fiber, so this isa key factor in determining the final propertiesof the composite material, particularly itsmechanical properties (Yosoyima et al., 1984;Yosoyima et al., 1990; and Pukzky et al.,1995). In the present work, an attempt hasbeen made to study the influence of glass fiberand carbon fiber reinforced epoxy polymermatrix on the mechanical properties. Thehybrid composites were developed by varyingthe reinforcements from 15%, 30%, 45% and60% of glass fiber and carbon fiber in 40%epoxy matrix under vacuum bag process. Thehardness and tensile properties were studiedas per the ASTM standards.EXPERIMENTAL DETAILSMaterial SelectionThe E-glass fiber and Carbon fibers areselected as reinforcements and Epoxy asmatrix material. The epoxy resin and hardenerTri Ethylene Tetra Amine (TETA) were providedby Atul Ltd. Polymers division, Valsad, Gujarat,India. The Glass Fiber of bi-directional wovenmat with 200 gsm and the density of 2.5 gm/cc. The Carbon Fiber of bi-directional wovenmat with 200 gsm and the density of 1.78 gm/Figure 1: The Glass Fiber and CarbonFiber133Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015cc were used. The glass fiber and carbon fiberused in the fabrication of hybrid fiber reinforcedcomposites are shown in Figure 1.Fabrication of CompositesThe Glass/Carbon fiber/Epoxy based hybridcomposites were developed using vacuum bagprocess by varying both the reinforcements interms of weight percentage of 15%, 30%, 45%and 60% of glass fiber and carbon fiber in 40%of Epoxy matrix. The weight fraction of fibersand epoxy matrix materials were determinedby considering the density, specific gravity andmass. Initially, the fabrication of the compositewas done at room temperature by hand lay-uptechnique. The required ingredients of resinand hardener were mixed thoroughly in a basinand the mixture is subsequently stirredconstantly. The required sizes of fiber matswere prepared and the glass fiber waspositioned manually in the open mold and themold surface must be smooth enough toprevent bonding to the laminate. The mixtureso made is brushed uniformly over the glassand carbon plies alternatively. The entrappedair is removed manually with squeezes orrollers to complete the laminates structure.Then the vacuum bagging is applied to themold with a vacuum pressure 0.1 m bar foruniform distribution of resin and also to removethe entrapped air. The composite is cured atroom temperature and the post curing wasdone at 50 °C for 30 min, 65 °C for 45 min and75 °C for 1 hour. The Fiber reinforced PMCsis mainly used due to easy availability of glassfibers and economic processing techniqueadopted for producing the Fiber-reinforcedPMCs. The vacuum bagging process adoptedfor the development of hybrid composite isshown in Figure 2.Specimen PreparationThe glass fiber and carbon fibers reinforcedepoxy composite slabs were taken out fromthe mold and then specimens of suitabledimensions were prepared from the compositeslabs for different mechanical tests accordingto ASTM standards. The test specimens werecut by slabs by using diamond tipped cutterand different tools in the work shop. Tensiletest specimens were prepared according toASTM D638. Test specimens havingdimension of length 60 mm, width of 12 mmand thickness of 3 mm. Micro hardness testspecimens were prepared according ASTMstandard. Three identical test specimens wereprepared for different test.Testing of FRP CompositesMechanical properties of composites wereevaluated by tensile and hardnessmeasurements. The specimens wereprepared from the developed composites andedges of the specimen are finished by usingfile and emery paper for tensile testing. Tensiletests were examined according to ASTMD638. The specimen was loaded between twomanually adjustable grips of a 60 KNcomputerized Universal Testing Machine(UTM) with an electronic extensometer and theFigure 2: Vacuum Bag Process134Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015surrounding temperature is 35 °C. A tensile testspecimen placing in the testing machine andload was applied until it fractures. Due to theapplication of load, the elongation andmaximum load of the specimen is recorded.Test was repeated thrice and the averagevalue was taken to calculate the tensile strengthof the composites. Micro hardness test wasconducted as per ASTM standard on thespecimen using a Vickers micro hardnesstester. The hardness was measured at threedifferent locations of the specimen and theaverage value was calculated.RESULTS AND DISCUSSIONHardnessHardness is described as resistance to surfaceindentation of the material. The variations ofmicro hardness of the composite materials areshown in the Figure 3. This graph explains theeffect of glass fiber and carbon fiberreinforcements on the micro hardness of thehybrid composites. The carbon fiber reinforcedepoxy composite exhibits higher microhardness as compared to other twocomposites. The 60% carbon fiber reinforcedcomposites shows 14.29% increase in themicro hardness as compared to 60% glassfiber reinforced composites and 23% increasein the micro hardness with that of 30% glassfiber and 30% carbon fiber reinforced hybridcomposite. The increase in the hardness inthe composites is the indication of goodbonding between the matrix and thereinforcement materials.Tensile StrengthFigure 4 shows the effect of reinforcement onUltimate Tensile Strength (UTS) of the fiberreinforced composites. The ultimate tensilestrength of the carbon reinforced compositewas higher as compared to other type ofcomposites. The 60% carbon fiber reinforcedcomposites shows 65.24% increase in theUTS as compared to 60% glass fiberreinforced composites and 38.01% increasein the UTS with that of 30% glass fiber and30% carbon reinforced hybrid composite. TheUTS of carbon fiber reinforced composite ishigher because the strength of carbon fiber ishigher and it behaves like elastic materialduring tensile loading. The inclusion of carbonfiber mat reinforced polymeric compositeFigure 3: Effect of Reinforcements onMicro Hardness of the Fibers ReinforcedCompositesFigure 4: Effect of Reinforcements on UTSof the Fibers Reinforced Composites135Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015significantly enhanced the ultimate tensilestrength of the composite.Yield StrengthThe yield strength of the glass fiber and carbonfiber reinforced epoxy composites dependsupon the strength and modulus of the fibers,strength, and chemical stability of the matrix,fiber matrix interaction, and fiber length. The60% carbon fiber reinforced compositesshows 61.31% increase in the yield strengthas compared to 60% glass fiber reinforcedcomposites and 30% increase in the yieldstrength with that of 30% glass fiber and 30%carbon reinforced hybrid composite. Figure 5shows the effect of reinforcements on yieldstrength of the fibers reinforced composites.Yield strength increases with increase inaddition of reinforcement to composites thismay be due to improved in interfacial bondingstrength between filler, matrix, and fiber.peak load withstand capability as comparedto 60% glass fiber reinforced composites and35% increase in the peak load withstandcapability with that of 30% glass fiber and 30%carbon reinforced hybrid composite. Thehybrid composite shows more peak loadwithstand capability as the carbon fiberreinforcement percentage increases in thehybrid composite.DuctilityThe variation of ductility of fiber reinforcedcomposites is shown in Figure 5. The ductilityFigure 5: Effect of Reinforcementson Yield Strength of the FibersReinforced CompositesPeak LoadFigure 6 shows the effect of reinforcementson peak load of the fibers reinforced hybridcomposites. The 60% carbon fiber reinforcedcomposites shows 68.52% increase in theFigure 6: Effect of Reinforcementson Peak Load of the Fibers ReinforcedCompositesFigure 7: Effect of Reinforcements onDuctility of the Fibers ReinforcedComposites136Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015of 30% glass fiber and 30% carbon reinforcedhybrid composite is lower as compared toother two composites. The 60% carbon fiberreinforced composites shows 26.19%increase in the ductility as compared to 60%glass fiber reinforced composites and 50.94%increase in the ductility with that of 30% glassfiber and 30% carbon reinforced hybridcomposite.CONCLUSIONThe carbon fiber and glass fiber reinforcedhybrid composites have been fabricated byvacuum bag method. Experimental evaluationof mechanical properties like micro hardness,tensile and flexural strength of hybridcomposites as per ASTM standards has beensuccessfully completed. The micro hardnessof carbon fiber reinforced composite is higherthan the other composites. The tensileproperties have been studied and the breakingload has been measured. The inclusion ofcarbon fiber mat reinforced polymericcomposite significantly enhanced the ultimatetensile strength, yield strength and peak loadof the composite. The ductility of carbon fiberreinforced composite is higher than the othercomposites.REFERENCES1. Amar Patnaik and Mahapatra S S(2009), “Study on Mechanical andErosion Wear Behavior of HybridComposites Using Taguchi ExperimentalDesign”, J. Materials and Design ,Vol. 30, pp. 2791-2801.2. Chauhan S, Kumar A, Patnaik A,Satapathy A and Singh I (2009),“Mechanical and Wear Characterizationof GF Reinforced Vinyl Ester ResinComposites with Different Co-monomers”, J. Reinf. Plast. Compos.,Vol. 28, pp. 2675-2684.3. Folkes M J (1992), “Multi ComponentPolymer Systems”, in Miles I S andRostami S (Eds.), Longman Scientificand Technical: Essex, Chapter 8, UK.4. Gururaja M N and Hari Rao A N (2012),“A Review on Recent Applications andFuture Prospectus of HybridComposites”, International Journal ofSoft Computing and Engineering(IJSCE), Vol. 1, No. 6, pp. 352-355.5. Manders P W and Bader M G (1981),“The Strength of Hybrid Glass/CarbonFibre Composites: Part 1 Failure StrainEnhancement and Failure Mode”,Journal of Materials Science, Vol. 16,pp. 2233-2245.6. Marom G, Fischer S, Tuler F R andWagner H D (1978), “Hybrid Effects inComposites: Conditions for Positive orNegative Effects versus Rule-of-MixturesBehavior”, Journal of Materials Science,Vol. 13, pp. 1419-1426.7. Prabhakaran R T D, Madsen B,Toftegaard H and Markussen C M (2012),“Flexural Properties of Hybrid NaturalComposite-Micromechanics andExperimental Assessment”, Proceedingsof 3rd Asian Conference on Mechanics ofFunctional Materials and Structures(ACMFMS), Vol. 1, pp. 469-472, IndianInstitute of Technology, New Delhi.8. Pukzky B, Maurer-Frans H J and BoodeJ W (1995), “Impact Testing of137Int. J. Mech. Eng. & Rob. Res. 2015 T D Jagannatha and G Harish, 2015Polypropylene Blends and Composites”,Polym. Eng. Sci., Vol. 35, pp. 1962-1971.9. Schwartz M M (1984), CompositeMaterials Handbook, McGraw-Hill, New York, USA.10. Suresha B, Chandramohan G,Siddaramaiah P, Sampathkumaran andSeetharamu S (2007), “Mechanical andThree Body Abrasive Wear Behavior of3-D Glass Fabric Reinforced Vinyl EsterComposites”, J. Mater. Sci. Eng. (A),Vol. 443, pp. 285-291.11. Yerramalli C S and Waas A M (2003),“Compressive Behavior of HybridComposites”, Proceedings of 44th AIAA/ASME/ASCE/AHS Structures, StructuralDynamics and Materials Conference,Norfolk, Virginia (AIAA-2003-1509).12. Yosoyima R, Morimoto K and Suzuki T(1984), “The Reaction of Glass Fiber withDisocyanate and its Application”, J. Appl.Polym. Sci., Vol. 29, pp. 671-679.13. Yosoyima R, Morimoto K, Susuki T,Nakajima A and Ikada Y (1990),“Adhesion and Bonding in Composites”,Marcel Dekker Inc., New York, USA.14. Zhang J, Chaisombat K, He S and WangC H (2012), “Hybrid CompositeLaminates Reinforced with Glass/CarbonWoven Fabrics for Light Weight LoadBearing Structures”, Materials andDesign, Vol. 36, pp. 75-80.

Mechanical Properties of Carbon/Glass Fiber Reinforced Epoxy Hybrid Polymer Composites

http://eprints-bangaloreuniversity.in/4278/1/MECHANICAL%20%20PROPERTIES%20%20OF%20%20CARBONGLASS.pdf

Mechanical Properties of Carbon/Glass Fiber Reinforced Epoxy Hybrid Polymer Composites

Abstract

Similar works

Full text

Available Versions

ePrints@Bangalore University