AbstractComposites are an important class of materials available to mankind. Studies of these composites are plays a very important role inmaterial science, metallurgy, chemistry, solid mechanics and engineering applications. The E-glass fiber reinforced polymercomposite are more widely used in the automotive industry and other industrial applications, due to their advantages, like low cost,noise control, low weight and ease of processing. Presently very limited work has been done on the mechanical properties of choppedstrand mat of E-glass fiber reinforced composites. The present project works aims to prepare E-glass fiber based composite withpercentage variation of glass fiber content like 1%, 2% and 3% with using a bisphenol A as matrix material and conducting themechanical ( tensile, compressive and flexural) testing on the composite. As a final point of view, mechanical results are comparedwith the FEA results by using analysis software like ANSYS.
Keywords: chopped strand mat E-glass fiber, polymer composites, Bisphenol A, FEA, mechanical test.
1. Introduction
Composite materials are an important class of materials which are now available to mankind in large quantity.Composite materials are important for mechanical, chemical and civil engineers, material scientists for using them on ahuge amount of engineering and other applications. Modern composites had started in 1930s. Nowadays thetechnological development increases on advances in the material field. The greatest advantage of composite materials isstiffness and strength together with light weight. Composites materials have properties, which could not be achieved byeither of the constituent materials alone. Researchers are finding ways to improve other qualities of composites so theymay be strong, lightweight, long-lived, and inexpensive to produce.Dr.P.K.Palani and M.Nanda [1] analyzed the mechanical Properties of E-glass fiber and they conclude that, tensilestrength of 1wt% and 7wt% of nanoclay composite is less compared to the 5wt% of nanoclay composite and also thehardness for 1wt% and 7wt% of nanoclay composite is low compared to 5wt% of nanoclay composite. Milan Zmindak,Martin Dudinsky [7], they studied computational modeling of composite materials reinforced by glass fiber. From thisstudy they conclude that fiber length is much greater than the critical length. Dr.N.Seetharamaiah, Dhanaraj Pamar [9],they conducted experiments on the mechanical behavior of composite material using FEA and they conclude thatcomposite materials with 600 angle are having less deformation and 900 having minimum strain.
2. Materials and methods
In this research work, materials tested consist of E-glass fiber reinforced composites with bisphenol A as matrixreinforced composites. The chopped strand mat E-glass fiber are used, supplied by Goa glass fiber limited (Binani)Mumbai. Tables1,2 shows the mechanical properties of the E-glass fibers and Bisphenol-A
Table 1 properties of chopped strand mat E-glass fiberTypes of fiber Young’s modulus (Gpa) Modulus (Gpa) Poisson’s ratio Density (gms/cc)
Chopped strand mat E-glass fiber 80 32 0.35 2.58
Table 2 properties of matrix materialTypes of matrix Molecular formula Melting point Boiling point Density (gms/cc)
Bisphenol A C15H16O2 1550 c 2200 c 1.20
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2.1 Procedure for preparation of composites
Initially to prepare Aluminum mould plate of dimensions length 251mm, width 130mm and thickness 4mm. The mouldis kept on a flat surface and releasing agent is sprayed over the surface of the mould due to reduce the sticking problem.Then the required amount of matrix material is weighed and poured in the glass beaker and add the catalyst, promoter,hardener and glass fiber with an equivalent proportion then mixes the mixture by using mechanical stirrer. After this itis allowed to kept some time to eliminate the air bubbles, after some time matrix material is poured in the mould byrandom orientation. The preparation of composite material is carried out by the hand layup techniques then material iskept allowed to cure under the room temperature for 24 hours before it removed from the mould. Then material is postcured in the air for another 24 hours after removing out of the mould, similarly to prepared the all the three differentpercentage variation such as 1%, 2% and 3% of composites. Then cut the materials with suitable dimensions as perASTM standard by using a mechanical cutter.
2.2 Testing of mechanical properties
The test specimens are tested under the tensile, compressive and three point bending. These test specimens were testedin gogte institute of technology, mechanical department, Belagavi. The test was conducted on Universal testing machineand samples are prepared and tested as per ASTM standards.
2.2.1 Tensile, Flexural and Compression testThe tensile test specimens were prepared according to ASTM D3039 standard. The tensile test was carried out usingUniversal testing machine. The machine has two cross heads driven to apply the load at test specimen and other one isadjusted for the length of the specimen. Test process was involved by placing a test specimen in the machine with agauge length of 200mm and load is applied. When the load (tension) increases rapidly then specimen starts to elongateuntil specimen breaks, then the applied load against the elongation was recorded. The Flexural test specimens wereprepared according to ASTM D790-02 standard and the compression test specimens are prepared according to ASTMD695-02a standard. Similarly flexural and compression test was carried out using Universal testing machine at GITcollege Belgaum.
Table 1 Results from mechanical testingTensile Bending compression
ANSYS is general purpose finite element analysis software package. This type of analysis is typically used for designand optimization of systems which are too complex to analyze by hand. This method allows to model compositesmaterials with specialized elements called layered elements. ANSYS simulation involves mainly three steps,preprocessing, solving and post processing. Preprocessing involves creation of geometrical model, nodes, elements,assigning materials properties etc. Solver part involves solution of equations. ANSYS provides various solvers the totalwork consists for composites structure can be completed from design to final information as a result.
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Figure 1 Mean deformation for tensile test for 1%, 2%, 3%
Figure 2 Mean deformation for bending test for 1%, 2%, 3%
Figure 3 Mean deformation for compression test for 1%, 2%, 3%
From Figure 1 to Figure 3 clearly shows that with increasing the % of glass fiber content, the deformation also goes onincreasing.
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3. ANSYS results and discussionFinite element Analysis is a numerical method of a complex system into very small pieces called elements. Thesoftware uses equations that generate the behavior of these elements and solves them all. The results can be presented asbelow,
Figure 4 Deformation for pure epoxy Figure 5 Total deformation for 1%
Figure 6 Total Deformation for 2% Figure 7 Total Deformation for 3%
From fig 4 to figure 7 clearly shows that, the total deformation of the specimen increases with increasing the load.
Figure 8 Total deformation for pure epoxy Figure 9Total Deformation for 1%
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Figure 10 Total Deformation for 2% Figure 11 Total Deformation for 3%
Figure 12 Total Deformation for pure epoxy Figure 13 Total Deformation for 1%
Figure 14 Total Deformation for 2% Figure 15 Total Deformation for 3%
Figure 16 and 17 shows that the experimental deformation is more than the FEA deformation because this differencecan be observed due to the presence of inhomogenities such as air bubbles which are present in the specimens and alsoimproper mixture of reinforcement and matrix. From the experimental values we calculated the Tensile, bending andcompressive strengths of the pure epoxy and various percentages (1%, 2% and 3%) of the composite materials and alsothe modulus of the composite materials. By using these values we plotted the Effect of glass fiber content on tensilestrength of various % as shown below.
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Figure 16 Comparison of FEA and experimental deformation for a) tensile test and b) bending test.
Figure 17 Comparison of FEA and experimental deformation for compressive test
Figure 18 effect of glass fiber content on tensile strength
Figure 19 effect of glass fiber content on bending strength.
From figure 18 to Figure 20 shows the effect of fiber content on various % (pure epoxy, 1%, 2% and 3%) of glass fiber.The strength of composite material increases with increasing the percentage of glass fiber content. From the above figthe strength for 3% reinforcement is more than 1% and 2%.
(a) (b)
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Figure 20 Effect of glass fiber content on Compressive strength of various %
4. ConclusionsThe present work concludes the successful preparation of composite materials by using the E glass fiber reinforcedepoxy composite and testing of new class of epoxy composites reinforced with using the glass fiber and the bisphenol Aas a matrix material. From this research we conclude that,
I. The tensile strength of 3% of glass fiber is more than the 1% and 2%II. The flexural (bending) properties of composites are analyzed under the three point bending test. From this
bending test the results show that as the % of glass fiber decreases the strength of material also decreases.III. The compressive properties are analyzed by using compression test. From this test we conclude that
compressive strength for 1% is less than the 2% and 3% of glass fiber content.
From these three tests the results shows that, the flexural (bending) strength is more at 3% of glass fiber content. Alsofor tensile strength the same trend is followed. The compression test results show that 2% reinforcements provide betterresults. The result from the FEA and experimental values matches closely. The experimental values are more than theFEA values. These results can be attributed to the presence of inhomoginites such as, mixture of matrix and reinforcedmaterial thoroughly, air bubbles presence in the specimens and agglomeration of reinforcements.
References[1] Dr.P.K.Palani,,M.Nanda kumar: Analysis Of Mechanical Properties Of Chopped Strand Mat E-Glass Fiber Epoxy Resin
Nanoclay Composites, Volume2, Issue 2, Pages 185-189 2013.[2] X. Huang, X. Yu, C. Wang, G. Li, Y. Song, K. Lu, E. Niu, C. Gung, N. Clayton, and M. Su, Interlaminar Shear Strength
Property of the Glass Fiber/Polyimide Reinforced Epoxy Resin for ITER Feeder Mock-ups, vol. 24, no. 3, june 2014.[3] Mohd. Zulfli, N. H., Abu Bakar A. and Chow W. S. and thermal behaviors of glass fiber reinforced epoxy hybrid composites
containing oregano-montmorillonite, Vol. 7 2012.[4] Martin Nezadal_y, Jan Sch¨ur_ and Lorenz-Peter Schmidt,Non-destructive Testing of Glass Fiber reinforced Plastics with a
Synthetic Aperture Radar in the lower THz region.[5] Lianhua Fan, C. P. Wongv, Thermosetting and Thermoplastic Bisphenol A Epoxy / Phenoxy Resin as Encapsulate
Material:2001[6] Amjad J. AREF1 and Woo young Jung: Analysis and experimental studies of composite materials, August 1-6, 2004
Paper No. 2479.[7] Milan Zmindak. Martin Dundinsky, Computational Modeling of composites Materials Reinforced by Glass Fibers.[8] Kusmono and Zainal Arifin Mohd Ishak: Effect of clay addition on mechanical properties of unsaturated polyester/glass fiber
composites, international journal of polymer science, volume 2013.[9] Dr. N.Seetharamaiah,J.Dhanraj,Afroz Mehar. S.Irfan sadaq,Characterization and Mechanical behavior composite material
using FEA, volume 2, pp: 125-131,International journal of engineering science.[10] Ashwini Kumar, Deepak Choudary: Development of glass fiber Reinforced Epoxy composite[11] Satnam Singh, Pardeep Kumar, S.K.Jain, An Experimental and numerical investigation of mechanical properties of glass fiber
reinforced epoxy composites.[12] G.Rathnakar, H.K.Shivanan, Experimental Evaluation of Strength and stiffness of Fiber reinforced composites under flexural
loading.[13] H. Yilmaz, Tensile strength testing of thin spray- on liner products and shotcrete.[14] Brayan Harris Engineering Composite, Material book, The Institute of Material London[15] Mechanics of composite materials, second edition by Autar K.Kaw, 2006 by Talor and Francies.[16] Finite Element Analysis of Composite Materials, by Ever J.Barbero. 2008 CRC Press, Talor and Francies Group.[17] Glass fibers and their use in reinforced plastics by A.R.Henning, Fiberglass Ltd,Helens.[18] Engineered Materials Handbook Vol.1 ASM International, 1987.[19] ASTM D3039/3039M, Standard test method for tensile properties of polymer matrix composites materials.[20] ASTM D 790-02, Standard test method for Flexural properties of unreinforced and reinforced plastics and electrical insulating
materials.[21] ASTM D 695-02a, Standard test method for Compressive properties of rigid plastics.
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