Analysis of mechanical properties of glass and carbon fiber reinforced polymer material

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1 Analysis of mechanical properties of glass and carbon fiber reinforced polymer material D.Bino prince raja Noorul Islam Centre for Higher Education, Kumaracoil , International Journal of Applied Engineering Research ISSN Volume 10, Number 11 (2015) B. Stanly Jones Retnam Noorul Islam Centre for Higher Education, Kumaracoil , ] M. Ramachandran MPSTME, SVKM S NMIMS. Shirpur, Dhule , Maharashtra, sweetestchandran@gmail.com ] M. Sivapragash Noorul Islam Centre for Higher Education, Kumaracoil , India. Abstract FRP materials have significantly expanded their application in Manufacturing Industry in recent years. Although light weight, low cost, superior corrosion resistance, and simple maintenance have been recognized as major advantages of using FRP materials, the design of fiber reinforced material are typically not as well understood as those for metallic counterpart. Long term degradation of FRP requires distinctive strength design methods, acceptance criteria and testing procedures. For conducting the test like tensile test and compressive strength in universal testing machine for the flat FRP was unavailable. Glass fiber alone will have very less young s modulus, Poisson s ratio and shear modulus because of this disadvantage, this material was not recommended for many works in ship. But carbon fiber is having very good mechanical properties but it is too costly and the orientation of the fibers also plays a vital role in the mechanical properties of the materials. In this paper we discuss the new setup and system to conduct tensile and compressive test for the flat fiber reinforced plastic material and conducting the test for the hybrid fiber reinforced plastic with carbon and glass fibers in the universal testing machine. From the data got from tensile and compressive test, the values of young s modulus, tensile strength and compressive strength and Poisson s ratio of the hybrid FRP composite materials. Key words: FRP, Carbon Fiber, Glass Fiber, young s modulus I. Introduction [1][2]For FRP composites the main research and development challenges today concern material characterization and the need to ensure that the properties assumed in design are compatible with those achieved by the real production process. The situation is made especially difficult by the constant introduction of new or modified component materials and new processes. For performing the test on the fiber reinforced plastic material is still need more technology so there is a lagging in the FPR material characterization and in this paper we are introducing the new system for carrying out the tensile test and compressive test in the universal testing machine to get the accurate result. There is particular uncertainty about the influence of production defects and damage, especially on the compression strength of laminates with carbon or other high strength fibers. Due to the poor mechanical properties of the glass fiber reinforced plastic material; we need to go for the alternative material like carbon and other natural fibers. Carbon fibers are too costly so we are going for the combinations of glass fiber with carbon fiber to get the required mechanical properties. Other topics requiring R&D concern improved fire performance, including lightweight fire protection systems, development of reliability based design codes that take proper account of the multiplicity of failure mechanisms that are possible with composites, proper characterization of nonlinear structural behavior including buckling, and recycling. II. Glass Fiber Material [3]Glass fibers material is having a various combinations of B 2 O 3, SiO 2, Al 2 O 3, Mg O, or Ca O in a powder form. Then the combinations are heated with heated through melting directly to temperatures around thousand three hundred degrees Celsius after that various dies are used to extrude glass fiber in filaments form in diameter in the ranging of 9 to 17µm. Then the glass fiber filaments are made into larger threads thereby it made into spun onto bobbins, which is convenient for further transportation and further processing. Glass fiber material in past is the most popular in the world by means of using to reinforce plastic and thus it as a very good place in the production process. It is significantly cheap and easily available when compare to the other fiber materials like carbon fiber and aramid fiber. The only disadvantages of the glass fiber are it cannot withstand more temperature like carbon fiber. process of making filaments is spun into larger diameter threads is called roving process and the glass fiber threads are familiarly used in the spray applications and in woven reinforcing glass fabrics. Reinforcing glass fiber fabrics are the web form reinforcing fabric material which has both warped and also the direction is weft. Glass fiber material mats are nonwoven and web form mats of glass fibers. Glass fiber materials mats are manufactured as continuous mats with the help of continuous glass fibers and also in small dimensions with cut glass fibers. Usually for the ship super structure we need a continuous mat with continuous glass fibers. Chopped fiber glass mat are used in processes most 10387

2 commonly for moulding processes, where the length of glass fiber threads is between 3 and 26 mm. Table 1 Mechanical properties of glass fiber FRP Sl.No Parameters GFRP 1 Youngs modulus in N/mm Poisson s ratio Shear modulus in N/mm Fiber volume fraction in % 50 III. Carbon Fiber Carbons fiber material is created by when the poly acryl nitrite fibers or Pitch resin or Rayon are carbonized at higher temperatures. Through further processes of graphitizing or stretching the fibers strength or elasticity can be enhanced respectively. Carbon fibers are manufactured in diameters analogous to glass fibers with the diameters ranging from 9 to 17µm. These fibers wound into larger threads for transportation and further production processes. Table 2 Mechanical properties of Carbon Fiber FRP Sl. No Parameters Values 1 Youngs modulus in N/mm2 2 Poisson s ratio Shear modulus in N/mm2 4 Fiber volume fraction in % 3200 [5]After that the carbon fiber material goes for further processes which include weaving or braiding which leads to carbon fabrics, cloths and mats as the same way of glass fiber material that will be used as actual reinforcements. IV. Epoxy Resin Epoxy is the cured end product of epoxy resins, as well as a colloquial name for the epoxide functional group. Epoxy resins, also known as poly epoxides are a class of reactive pre polymers and polymers which contain epoxide groups. Epoxy has a wide range of applications, including metal coatings, use in electronics / electrical components, high tension electrical insulators; fiber reinforced plastic materials, and structural adhesives. V. Wet Layup Wet layup forming process is one of the types of fiber reinforcement material manufacturing process. This process includes the matrix which is placed on the forming tool. Both the carbon reinforced fiber layer and glass reinforced fiber layer are placed in an open moulding process. Usually the resin was taken 70 percentage of its volume and remaining 30 percentages of carbon fiber and glass fiber are taken in combinations as shown in the table 3. Table 3 Composition of hybrid FRP material 50 Sl. Type No s of layer 1 Carb on fiber 2 Glass fiber Percent age in hybrid 30 Then it is saturated with the epoxy wet resin by pouring on the reinforced fiber layer.then the reinforced fiber layer mould is with the wet epoxy resin is allowed to cool in the normal room temperature and vacuum bags are used to compress the reinforced fiber layer for getting the better result. For getting the better result we can still keep the mould at different temperature level to get the best temperature level for getting the very good mechanical properties. VI. Tensile test for hybrid FRP The hybrid FRP specimens used in this study were cut from the 14 mm thickness of rectangular sheet manufactured by using vacuum bags assisted wet layup resin moulding process. Tables 3 show the percentage of carbon fibre and glass fibre in the hybrid fibre reinforced plastic sheet by volume. The mechanical properties of each carbon fibre and glass fibres were tabulated in the table2 and table 1 respectively. For the test purpose we are cutting the specimen in two ways from the rectangle sheet. The specimen cutted along longitudinal axis of the sheet is taken as 01 and the specimen cutted along the transverse axis is taken as 02 specimen and the dimensions of the specimens were taken as per the table4. Table 4 Dimensions of the Specimen for tensile test Speci men 70 No of specimen Total length Gauge Lengt The hybrid fibre reinforced plastic material length was taken based on the maximum clearance of universal testing machine and based on the recommendation of the ASTMD 3039 code the gauge length is taken for FRP composite specimen tension test. For best gripping to hold the thick hybrid FRP specimens is not available. To make the tension test in the existing testing machine special type of holding system was made as per the figure 1. The special holding system consists of steel pipe filled with low viscosity epoxy with high strength in between the steel pipe and the flat fibre reinforced plastic specimen for performing the tensile test under tensile loading. The holding system was the modification of standard tensile tests for fibre reinforced bars based on ACI440.3R

Fig. 1: details of tensile test specimen with steel holder. [6]The steel pipe was taken as per the figure 3 which is having the stipulated dimensions with internal thread to get better grip.

3 Fig. 1: details of tensile test specimen with steel holder. [6]The steel pipe was taken as per the figure 3 which is having the stipulated dimensions with internal thread to get better grip. The steel pipe was cleaned with acetone and adhesive was provided in the contact area then the specimen is kept at centre and epoxy was poured. Leakage of epoxy was prevented by duct tapes. The specimen was kept for 24 hours to get better fixed in steel pipe and hardened. Strain gauge with metallic foil type was attached on both sides in both horizontal and vertical direction along the centre line of fibre reinforced plastic material. Table 5 Mechanical properties of Hybrid FRP in tension Sl.No Parameters Specimen 01 Specimen 01 1 Youngs modulus 2 Poisson s ratio Tensile strength The procedure and the test set up was made based on the ACI440 3R and ASTMD3039 specifications. The universal testing machine with 500kN capacity was used for the test. The hybrid specimen end with steel pipe was loaded in the wedge friction metal grips of the universal testing machine. Strain rate of 100 micro strains was made by applying load until final failure. Load and strain during the test was recorded by data logger. All the specimens were tested in the same format. The final average values of the young modulus, tensile strength and Poisson s ratio. The young s modulus was calculated with the help of stress and strain created in the specimen. The tensile strength was calculated from average thickness and width of specimen and maximum tensile load. Poisson s ratio was calculated from lateral and linear strain. The specimen 01 is having the maximum stiffness and maximum strength. The specimens 02 are having low strength and stiffness when compare with 01 specimen. The difference of modulus value was less than difference of tensile strength values this can be due to the imperfections created during the manufacturing process. VII. Compressive test for Hybrid FRP For the compressive test the dimension of the specimens was taken as per the table 6 were taken. All the specimens were taken similar composition of the tensile test composition for the compressive test. The specimen A1 denotes that the specimen were tabbed with glass fiber reinforced plastic laminates at both ends with 30mm length and the A2 specimen denotes the specimen were inserted in the steel pipe as same as for tensile test and filled with the epoxy with adhesives. Both the A1 specimen and the A2 specimen will have a gauge length of 80mm after tabbed with either steel pipe or glass fiber reinforced plastic. These kinds of arrangements were done on the specimens for performing the strength test without end crushing. Table 6 Dimensions of the Specimen for compressive test Specimen No of specimen A A A A B B B B For the compressive modulus the specimens used for test were similar to strength test but the ends were not tabbed. For performing the compressive modulus test, two specimens were taken namely B1 specimen and B2 specimen. Bothe the specimen were untabbed and having the dimensions of 140mm and 80mm. The test set up and the procedure for performing the strength test and compressive modulus test was done under compressive load with the help of developed test fixture. These developed test fixture was designed and fabricated based on the ASTM 3410 code. The compressive load was introduced to the hybrid fiber reinforced plastics specimens through the end loading to get accurate result. For measuring the strain occurred in each hybrid FRP specimen was done by using foil resistance strain gauges was applied back to back in the measuring section to get the best result. For calculating the compressive modulus and to determine the strain to failure, the strain data of the specimens were used. The amount of bending of the of the hybrid FRP specimens while conducting the test was done by using back to back strain gauges. To fix the hybrid FRP test specimen in the fixture at first the specimen was inserted in the cap heads with the bolts and placed with the test fixture. The cap head along with specimen was placed on the top loading platen in the circular groove. While fixing in the platen the fixing bolts was loosened slightly to make the specimen top surface pressing on the top platen. After that the fixing bolts in the test fixture were then again tighten with hand tight. Then the test fixture was turn over slowly for inserting the lower end cap head in the bottom loading platen in the circular groove. The test fixture upper half rest against the FRP specimen top face. Then the lower head cap fixing bolts was loosened slightly to make the test specimen pressing the lower loading pattern. After that the lower head cap fixing bolts was tighten with finger tight. Than a load guide steel was passing through the bored hole precisely made in the 10389

4 loading platens bottom side was fixed on the loading platen top side for maintaining the alignment of test specimen during the loading. Finally the test specimens was inspected to ensure the hybrid FRP specimen of both ends were perfectly even with the bottom and top side of the loading platens. TABLE 7 Mechanical properties of Hybrid FRP in compression After the hybrid FRP specimen was accurately mounted Specimen Young s Compressive Poisson s modulus strength ratio A A A A B B B B on the test fixture. The test fixture will place on the universal testing machine and the tests were carried out. By using the universal testing machine the hybrid FRP test specimens were compressed and the corresponding deformations at the various load conditions were recorded. As recommended by the ASTM 3410 code. The compressive load was given at the rate of 1.27mm/min in displacement control and the load was measured with the help of 300kn load cell at the bottom of the test fixture. The effective compressive modulus and compressive strength of all the (A1, A2, B1, B2 )hybrid fiber reinforced plastic composite laminates with 0 degree orientation and 90 degree orientation were reported in the table 7. The mechanical properties of compressive modulus and compressive strength were calculated by using the compressive test data. The compressive modulus was calculated based on the stress strain value of the each specimen. And the compressive strength was calculated from the maximum compressive load and average thickness and width of the specimen. As per the tabulated value in the table 7 the 01 specimen will have the highest strength and stiffness and the 02 specimen will show the less strength and stiffness when subjected to the compressive loading which is similar to the tensile test report. The variations in between the values of young s modulus, poisson s ratio and compressive strength are less than 10% which proves that the test fixture provides consistent results. This less than 10 percentage difference is acceptable in conducting fiber composite materials pointed out by Weiner and Wolfe. The difference on compressive modulus of each specimen is lower than difference of compressive strength value. It also shows the young s modulus is less sensitive to defect when compare to the strength of the materials. When compare to tensile strength valves, the compressive strength values is lower. This is due to the existence of manufacturing defects in the hybrid fiber reinforced plastic composites such as voids and internal micro cracks which tends open in conducting the tensile test. VIII. Conclusions The system used for holding the flat FRP specimen for performing the tensile test and compressive test was given accurate result. In the tensile test the failure was occurred in the gauge length of the specimen this proves that the holding mechanism was worked out correctly. The young s modulus of the specimens both in tensile test and compressive tests were found out. When compare with the glass fiber reinforced plastic material, the hybrid composites with glass fiber and carbon fiber was having the very good mechanical properties. So this hybrid fiber reinforced composites was used for the replacement of glass fiber reinforced plastic material where there is a need of very good mechanical properties. The test set up also easy to use and it is economical when compared with unconventional test and it will give reliable data for the composite materials. The variations in the results are less than ten percentages which proves that the experimental test was conducted between the margins of error. To get the precision result it is recommended to have more number of samples, thereby the coefficient of variation of the measured value will be reduced. The fiber reinforced plastic with mixture of carbon fiber and plastic fiber will increase the strength and stability of the material. Less amount of carbon fiber will reduce the cost of the material and thereby we can get the best material at the less cost. The methodology for determining the structural properties and critical temperature at which an FRP structure fails has significant merits. References [1]. ABS Guide for Certification of FRP Hydrocarbon Production Piping System, American Bureau of Shipping, [2]. API Spec 15HR High Pressure Fiber Glass Line Pipe, American Petroleum Institute, 2004 [3]. API Spec 15LR Low Pressure Fiber Glass Line Pipe, American Petroleum Institute, 2001 [4]. ASTM D1599 Standard Test Method for Resistance to Short-Time Hydraulic Failure Pressure of Plastic Pipe, Tubing, and Fittings, American Society for Testing and Materials, 1999 [5]. ASTM D2105 Standard Test Method for Longitudinal Tensile Properties of Fiberglass (Glass- Fiber-Reinforced Thermosetting- Resin) Pipe and Tube, American Society for Testing and Materials,

5 [6]. ASTM D2925 Standard Test Method for Beam Deflection of Fiberglass (Glass-Fiber-Reinforced Thermosetting Resin) Pipe Under Full Bore Flow, American Society for Testing and Materials,2001 [7]. ASTM D2992 Standard Practice for Obtaining Hydrostatic or Pressure Design Basis for Fiberglass (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe and Fittings, American Society for Testing and Materials, 2001 [8]. ASTM D Standard Specification for Filament-Wound Fiberglass (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe, American Society for Testing and Materials, 2001 [9]. ASTM D790 Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials, American Society for Testing and Materials, 2003 [10]. ASTM F Standard Specification for Thermosetting Resin Fiber glass Pipe Systems to Be Used for Marine Applications, American Society for Testing and Materials, 2006 [11]. Composite Material for Offshore Operations 2, S. Wang, J. Williams, and K. Lo, Ed., University of Houston, 1999 [12]. Dastidar, A., Dahn, C., Cole, B., and Lo, K. Electrostatic Characteristics of FRP Pipes, Fourth International Conference on Composite Materials for Offshore Operation, Houston, TX, Oct 4-6,2005 [13]. ISO Petroleum and Natural Gas Industries Glass-Reinforced Plastics (GRP) Piping, International Standard Organization, [14]. ISO Ships and Marine Technology Standard specification for thermosetting Resin Fiber Glass Pipe and Fittings to be Used for Marine Applications, International Standard Organization, 2004 [15]. SOLAS, Ch.II.2, Construction Fire Protection, Fire Detection, and Fire Extinction, July (in Ref. 7) [16]. Manley, D: Procuring for survivability, in proceedings of the International Symposium, WARSHIP2001 Future Surface Warships, RINA, June 2001, London, The UK. [17]. Manley, D: The Development of "Smart" requirements for Ship Survivability, NATO RTO Symposium on Combat Survivability of Air, Space, Sea and Land Vehicles, Aalborg, Denmark, September [18]. Wright, D. J.: The integration of vulnerability targets into warship vulnerability, NATO RTO Symposium on Combat Survivability of Air, Space, Sea and Land Vehicles, Aalborg, Denmark, September [19]. McGeorge, D., Høyning, B.: Fire Safety of Naval Vessels Made of Composite Materials: Symposium on Combat Survivability of Air, Space, Sea and Land Vehicles, Aalborg, Denmark, September [20]. Van Aanhold, J.E., Groves, A., Lystrup, A and McGeorge, D.: Dynamic and Static Performance of Composite T-joints, NATO RTO Symposium on Combat Survivability of Air, Space, Sea and Land Vehicles, Aalborg, Denmark, September [21]. Clifford, S.M., Manger, C.I.C. and Clyne, T.W.: Characterisation of a Glass-Fiber Reinforced Vinyl Ester to Steel Joint for Use between a Naval GRP Superstructure and a Steel Hull, Composite Structures 57, 59-66,. [22]. S. Shah, A. Patil, Ramachandran. M, K. Kalita. Effect of coal ash as a filler on mechanical properties of glass fiber reinforced material. Int. J. of Applied Engineering Research (IJAER), Volume 9, Issue

Carbon Fiber Epoxy Composites and Its Mechanical Properties. Hitesh Pingle 1

ISSN UA Volume 01 Issue 01 June-2018 Carbon Fiber Epoxy Composites and Its Mechanical Properties Hitesh Pingle 1 Available online at: www.xournals.com Received 15 th December 2017 Revised 19 th February