International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:01

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Vibration Damping Characteristics of Hybrid Polymer Matrix Composite Dr.P.S.Senthil Kumar1, Karthik.K 2,Raja.T3 Department of Mechanical Engineering., VEL TECH UNIVERSITY,Avadi,Chennai-600 062, Tamil nadu,India 1 [email protected], [email protected],[email protected], Abstract— This paper aims to study the damping characteristics of Hybrid polymer composite, which can be used in many applications and in engineering structures. The investigation aims to develop glass-epoxy composite with addition of carbon(600mesh) fillers with different weight fractions and to characterize the mechanical and damping properties. The carbon filler are used reinforcement and fabricated using Hand lay-up and vacuum bag molding technique. The damping characteristics were evaluated using free and forced vibration test with different amplitudes. The result indicates that the damping characteristics improved with increase in weight percentage of carbon reinforcement content. Further it was found that glass fiber – epoxy matrix with 5% carbon particles better damping properties which can be used for structural application. Index Term—

Glass fibre epoxy, carbon fillers, vacuum process, vibration, damping. 1. INTRODUCTION Vibrations are undesirable for structures, owing to the need for structural stability, position control, durability, performance and noise reduction. Vibrations are concern to large structures such as aircraft, as well as small structures such as electronics. Composite polymers have been used as dampers for their damping ability.This project aims to study the damping characteristics of Hybrid polymer composite, which can be used in many applications, and in engineering structures. Glass and carbon fibre reinforced with epoxy matrix hybrid composite have to be prepare by hand-lay-up and vacuum-bag molding fabrication technique .Then the free and forced vibration test will be perform by Fast Fourier Transformer analyzer (FFT) using LABVIEW. From this study the natural frequency, damping ratio and mode shapes is be determined.In recent years, there have been rapid growth in the development and application of fiber reinforced thermosetting polymer composites such as epoxy, polyester and vinyl ester. This is due to the realization of their good strength, low density and high performance to cost ratio with rapid clean processing. In recent times, there has been a remarkable growth in the large-scale production of fiber and/or filler reinforced epoxy matrix composites. Because of their high strength-to- weight and stiffness-to-weight ratios, they are extensively used for a wide variety of structural applications as in aerospace, automotive and chemical industries [1]. On account of their good combination of properties, fiber reinforced polymer composites (FRPCs) are used for producing a number of mechanical components such as gears, cams, wheels, brakes, clutches, bearings and seals.

Most of these are subjected to tribological loading conditions. The FRPCs exhibit relatively low densities and they can also be tailored for our design requirements by altering the stacking sequences to provide high strength and stiffness in the direction of high loading [2]. A number of material-processing strategies have been used to improve the wear performance of polymers. Glass fiber reinforced polymeric composites traditionally show poor wear resistance and high friction due to the brittle nature of the reinforcing fibers. This has prompted many researchers to cast the polymers with fibers/fillers. Considerable efforts are being made to extend the range of applications. Such use would provide economical and functional benefits to both manufacturers and consumers. Studies have been conducted with various shapes, sizes, types and compositions of fibers in a number of matrices [3-8]. A motion which repeats itself after a certain interval of time may be called a vibration. Vibration is the motion of the particle or a system of connected bodies displaced from of equilibrium. Vibration occurs when a system is displaced from a position of stable equilibrium under the action of restoring forces. The system keeps on moving back and forth across its position of equilibrium. Vibrations are undesirable for structural, owing to the need for structural stability, position control, durability (particularly against fatigue). Performance and noise reduction .Vibration are of concern to large structures such as air craft, as well as small structures such as electronics, vibration reduction can be attained by increasing the damping capacity (loss of energy) and/or increasing the stiffness (storage modulus). The loss modulus is the product of these two quantities and thus can be considered a figure of merit for the vibration reduction. Damping of a structure can be attained by passive or active methods. Passive methods make use of the inherent ability of certain materials (whether structural or non structural material) to absorb the vibration energy, Thereby providing passive energy dissipation. Active methods make use of sensor and actuators to attain vibration sensing and activation to suppress the vibration in a real time, the sensors and actuators can be piezoelectric devices. Materials for vibration damping are mainly 1.metals, 2.polymers and rubber because of their viscoelastic character.

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International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:01 Rubber is commonly used as a vibration damping material owing to its viscoelastic. However Viscoelastic is not only mechanism for damping. Defects such as dislocation, phase boundaries, grain boundaries and various interfaces also contribute to damping, since defects may move slightly and surfaces may slip with respect to one another during vibration, Thereby dissipating energy. Thus, The microstructure greatly affects the damping capacity of the material. The damping capacity depends not only on the material, but also on the loading frequency, as the viscoelasticity as well as defects response depends on the frequency. The damping capacity also defends on the temperature. Owing to the interface between reinforced (particles, whiskers or fibers) and matrix in a composite, Composite formation tends to increase the damping capacity, in addition to the well-known effects of increasing the stiffness. A high stiffness is useful for vibration reduction. However, metal matrix composites are expensive to make and their competition with the high damping alloy is difficult, a particular common form of composite is a laminate in which a high damping layer is sandwiched and constrained by stiff layers. The shear deformation of the constrained layer provides damping, while the stiff layer allows structural use of the laminate. Polymers for vibration damping areDue to their Viscoelastic behavior, polymers (particularly thermoplastic) can provide damping. Rubber is particularly well known for its damping ability. However, rubber suffers from low stiffness, which results in a rather low value of the loss modulus; other polymers used for vibration damping include polyurethane, The common Viscoelastic materials are 1.Acrylic rubber, 2.Polypropylene/butyl rubber blend, 3.Polyvinyl chloride/chlorinated, 4.Polyethylene/ epoxidized natural rubber blend, 5.Polyimide / Polyimide blend, 6.Polysulfide / Polysulfide blend, 7. Nylon-6/polypropylene blend, 8. Fluor silicon rubber, 9.Nits rile rubber, 10.Silicon rubber In General purpose of viscoelastic materials are used for low amplitude vibration damping, such as sound transmission and acoustical wave thought elastic media. Industrial uses of rubber products Isolation systems, automobile tires, bushing, mounts, seals, diaphragm, rubber pads, lubricants, speakers, machinery pads, electronic devices, etc.,In automobile engines and pump applications, bearing are very important to maintain smooth transmission of motion and enables noiseless operation. In general babbit metal, bronze, cast iron, gun metal and non-metals such as carbon, graphite and rubber are used for the construction of bearing. In recent development of material science polymer and ceramic composites are considered the most practical and light weight structural materials in the composite industries. Compared with conventional metal bearing with polymer and ceramic bearing have been shown to offer significant benefits in terms of rolling contact fatigue life, and the low density of material

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greatly reduce the dynamic loading in very high speed applications such as machine tools and aircraft and gas turbine engines. The technological developments in composite materials are responsible for partially meeting the global industrial demand for materials with improved performance capabilities. Polymer composites are used mainly in automobile and aircraft industries applications. Polymer matric are generally thermosets and thermoplastics polymers are being used as matrices. Unsaturated polyesters resins have been in use for decades in production of many industrial applications. For heavy duty structural applications epoxides, phenolic, and a few specialty polymer materials are used on a commercial scale. Polymers such as PEEK, PSUL, polyesters, vinyl ester, epoxies, polyamides etc. These polymers are used in many combinations in different fibers for developing the bearing materials with high wear resistance and less coefficient of friction. A composite material is a material composed of two or more constituents. The constituents are combined at a microscopic level and are not soluble in each other. The material holds the reinforcement to form the desired shape while the reinforcement improves the overall mechanical properties of the matrix. When designed properly, the new combined material exhibits better strength than would each individual material. The most primitive man-made composite materials are straw and mud combined to form bricks for building construction. In recent times there has been a remarkable growth in the large scale production of fiber and fiber reinforced epoxy matrix composites because of their remarkable properties. These are used in structural applications as in aerospace, automotive and chemical industry on account of their good combination of properties. Fibers reinforced polymer composites are used for producing number of mechanical components such as gears, cams, wheels, brakes, clutches, bush bearing and seals [9]. Considerable efforts are being made to extend the range of applications. Such use would provide economical and functional benefits to both manufacturers and consumers. Various researchers have studied the friction and wear characteristics on polymers such as epoxy, vinyl ester polyester. In aircraft and space vehicles high reliability and relatively long life are required of all assemblies and elements, including bearings. With the advent of the space era very demanding bearing operating conditions such as high vacuum, extreme temperatures, large temperature differentials, long life (both wear and fatigue life, usually 10–15 years without maintenance) and low frictional power are quite common [10,11]. These ever increasingly stringent demands present great challenges for those responsible for the development and validation of new rolling contact bearing materials. Analysis of hybrid jute-sisal fabric reinforced polyester composites. The hybrid jute-sisal laminate are prepared by hand lay-up technique using untreated woven jute and sisal as reinforced materials and commercially available polyester resin as a matrix material.

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International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:01 A cantilevered rectangular symmetric plate of hybrid jute-sisal fabric reinforced polyester composite having aspect ratio of 0.83 with 5 layers of cloth for hybrid jute-sisal laminate with fiber direction orientation at [+90°/+45°/0°/45°/-90°] laminate is prepared. In the analysis, a frequency domain model is used along with Frequency Response Function (FRF) measurements obtained from the plate. These measurements are made using a Fast Fourier Technique (FFT) based spectrum analyzer. Natural frequency, damping factor and mode shapes are obtained from the laminates.The objective of the present work is to determine the damping factor and mode shapes for a cantilevered rectangular symmetric plate of hybrid jute-sisal fabric reinforced polyester composite with fiber orientation at [+90°/+45°/0°/-45°/-90°] using a Fast Fourier Technique (FFT) based spectrum analyzer. Shape memory alloy (SMA) and piezoelectric (PZTLead Zirconium, Titanium) patches are commercially available for a variety of actuator and damping materials. These smart materials can be used for active vibration suppression of flexible structures. In this work SMA based and PZT based composites are presented for investigating the vibration characteristics. In first case, the smart beam consists of a Glass fiber reinforced polymer (GFRP) beam modeled in cantilevered configuration with externally attached SMAs. In second case, the smart beam consists of a GFRP beam with surface bonded PZT patches. A mathematical model is developed to study the behavior of the smart beam. The vibration suppression of smart beam is investigated using ANSYS. The experimental work is carried out for both cases in order to evaluate the vibration control of flexible beam for first mode, also to find the effectiveness of the proposed actuators. As a result the vibration characteristic of GFRP beam is more effective when SMA is used as an actuator.[16]

A active vibration control technique applied to a smart beam. The smart beam consists of Aluminum and mild steel beams modeled in cantilevered configuration with surface bonded piezoelectric (lead-Zirconium-Titanium-PZT) patches .The natural frequency of smart beams were found using finite element code for first four modes by varying the location of actuator from the fixed end of the structure, and it has good agreement with analytically found natural frequency. An experimental apparatus has been developed for the vibration suppression of the smart beams. The free vibration of the mild steel and aluminum beams were carried out by varying the initial displacement and input voltage to the PZT in order to find out the settling time and the damping factor of both of the beams. The results shows that the aluminum beam will have little more damping effect than mild steel leads to less settling time of aluminum. glass fiber to the PEEK makes a major difference in wear behavior and friction properties are improved. The pure PEEK composite and PEEK+ 30% glass fiber composite is tested in pin on disc apparatus with different speeds and

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pressure and different working conditions such as dry and water lubricated conditions. The particles such as graphite and wax materials are added in polymers called polyamide. The addition of particles in two different percentage 5% to 15% graphite and 4% wax. The wax added polymer exhibits better wear resistance and low coefficient of friction than graphite. Wax is cheaper product than graphite. As compared with graphite composite the wax composite is 20times ore resistant in dry condition [13] Use of inorganic fillers dispersed in polymeric composites is increasing. Fillers not only reduce the cost of the composites, but also meet performance requirements, which could not have been achieved by using reinforcement and resin ingredients alone. In order to obtain perfect friction and wear properties many researchers modified polymers using different fillers [14-22] 2. EXPERIMENTAL DETAILS

Fig.1.Carbon particle

Fig.2.E-Glass fiber

2.1 MATERIALS The following materials such as Glass fiber, epoxy resin and carbon particles are used. The E-glass chopped mat fabric of 0.4mm and epoxy resin (LY 556) with room temperature curing hardener (HY 951 grade) with diluent DY 021 mix was employed for the matrix material. The carbon particle[600_mesh] materials are used in the Glass and carbon-epoxy composite. The details is shown in table 2.1 Table I Details of prepared composite

Samples 1. 2. 3. 4.

Epoxy (wt %) 30 30 30 30

Glass (wt %) 70 65 60 55

Carbon (wt %) 5 10 15

2.2 FABRICATION PROCESS The fabrication process is done by vacuum bag molding. The vacuum bag molding is modification to the wet hand layup technique. The circular mold is prepared as per required beam dimensions (300mmx25mmx4.5mm). The Glass-epoxy material and carbon particles with different volume fractions is mixed and stirred manually. The mixed materials are poured into the prepared mold. The mold is placed inside the bag

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made of flexible film and all edges are sealed. The bag is then evacuated, so that pressure eliminates voids in the laminate, forcing excess air and resin from the mold. The laminate is then placed in the oven with 100°c temperature and kept for 1 hour for curing completely. The cutting operation is done for cutting the laminate into dimensions required for the test such as Free and Forced vibration by using LABVIEW software. 3.EXPERIMENTAL SET-UP

Fig. 5. Lab View Block diagram Table II Dimensions and properties of the composite beam

Length(m) width(m) Thickness(m) Young’s modulus(GPa) Density(g/cm^3) Volume fraction of glass fiber

Fig.3. Block diagram for free vibration test

3.1 Free vibration test

The system was displaced from its mean position and released .the resulting free vibrations are recorded. From which information regarding the natural frequency and damping can be obtained,In practice, a mechanical system under test is rapped by impact from a light hammer to include free vibrations.

Fig. 4.Experimental set up for free vibration test

l b t Ec c Vf glass

0.3 0.025 0.0045 34.40 1.98 0.7

3.2 forced vibration test External forces using by mini shaker.The system was displaced from its mean position and released .the resulting free vibrations are recorded. From which information regarding the natural frequency and damping can be obtained, In practice, a mechanical system under test is rapped by impact from a light hammer to include free vibrations

Fig. 6.Block diagram for forced vibration test

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Sample-1 ( Vf glass=70%,Vm=30%)

Fig. 7.Experimental set-up forced vibration test Table III natural frequency, damping ratio, loss factor, for composite beam

Sample

1 2 3 4

Loss factor in ( §)

Damping ratio in(€)

0.1508 0.1177 0.1541 0.2177

0.0239 0.0224 0.0245 0.0346

Natural Frequency (Hz) 25 25.6 25.6 26.6

in

Frequency in Hz

Table IV Experimental comparison of Natural frequency of the beam

27 26 Series1

25 1

Fig. 8.Vibration Amplitude (mm) Vs Frequency (Hz)

Sample-2 ( Vf glass=65%,Vfcarbon=5%,Vm=30%)

2

Damping Ratio

5.RESULT AND DISCUSSION 5.1 Natural Frequency: The density of the GFRP beam is about 1.98 g/cm3 is muchlesser than the density of the glass fiber. Therefore, thenatural frequencies of the GFRP with carbon beams aredecreased accordingly due to the increase of the overalldensity of the beams. However, thisphenomenon can bechanged by using composite materials with high tensilemodulus. The natural frequencies of the composite beamswith different volume of fiber.hat the natural frequencies initially decreases for the beamwith different volume fraction.The decrease of the natural. The frequencies are then increased withcontinuously increasing the damping ratio.5.2 Damping property: The damping property of the beam is testedBy free and forced vibration test then comparing results, AndDifferent compositions 5.1 shows the free vibration of theGFRP beam. and natural frequency. The Settling time decreases due to the increase in force generated by the hybrid composite beam.

Fig. 9. Vibration Amplitude (mm) Vs Time (sec) & Vibration Amplitude (mm) Vs Frequency (Hz)

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International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:15 No:01 Sample-3 ( Vf glass=60%,Vfcarbon=10%,Vm=30%)

[3]

[4] [5]

[6]

[7]

[8] [9] Fig. 10. Vibration Amplitude (mm) Vs Time(sec) & Vibration Amplitude (mm) Vs Frequency (Hz)

[10]

Sample-4 ( Vfglass=55%,Vf carbon=15%,Vm=30%) [11]

[12]

[13]

[14]

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composite. Journal of composite science and technology, Vol. 63, 2003, pp. 1629-1635. Zheng Wang ,Link Li, Meng Gong. Measurement of dynamic modulus of elasticity and damping ratio of wood-based composite using the cantilever beam vibration technique, journal of construction and building materials. Vol. 28, 2012, pp. 831-834. Binod P.Yadav. Vibration damping using four –layer sandwich, journal of sound and vibration, Vol 317, 2008, pp. 9576-5900. Theodore, L.Karavasilis, James, M.Richard Sause. Experimental evaluation of the seismic performance of steel MRF swith compressed Elastomer damper using large –scale real time hybrid simulation. Engineering structures, Vol. 33, 2011, pp. 1859-1869. Manex Martinez-Agirre, Maria Jesus Elejabarrieta. Dynamic characterization of high damping Viscoelastic materials from vibration test data. Journal of Sound and Vibration, Vol. 330, 2011, PP. 3930– 3943. B.Darabi, J.A.Rongong. Polymeric particle dampers under steadystate vertical vibrations. Journal of Sound and Vibration, Vol. 331, 2012, PP. 3304–3316. Y.Hong, X.D.He, R.G.Wang. Vibration and damping analysis of a composite blade. Material and design, Vol. 34, 2012, pp. 98-105. E.Salin, Y.Liu, M.Vippola. Vibration damping properties of steel/rubber/composite hybrid structures. Composite Structures, Vol. 94, 2012, pp. 3327–3335. Chensong Dong, Ian J.Davies. Optimal design for the flexural behavior of glass and carbon fiber reinforced polymer hybrid composites. Materials and Design, Vol. 37, 2012, pp. 450–457. Chensong Dong, Heshan A. Flexural properties of hybrid composite reinforced by S-2glass and T700S carbon fibers Composites. Composites Part B, Vol. 43, 2012, pp.573–581. Akash D.A, Thyagaraj.N.R, Sudev.L.J. Experimental study of dynamic behavior of hybrid jute/sisal fibre reinforced polyester composites. International Journal of Science and Engineering Applications, Vol. 2 Issue 8, 2013, pp. 2319-7560. Yuvaraja.M, Senthilkumar.M. Comparative study on vibration characteristics of a flexible GFRP composite beam using SMA and PZT Actuators, Manuf. and Ind. Engg, Vol. 11(1), 2012, pp. 13386549. Yuvaraja.M, Senthilkumar.M, I.Balaguru. Study on vibration characteristics of PZT Actuated mild steel and aluminum cantilever beams. International journal of engineering, Vol. 1, 2011, pp. 15842673.

Fig. 11.Vibration Amplitude (mm) Vs Frequency (Hz)& Vibration Amplitude (mm) Vs Time (sec)

CONCLUSION Based on the experimental observations, the following The design, characterization and testing of hybrid composite beam for use in active vibration control applicationshas been presented. In this study vibration damping characteristic behavior is compared. Both glass and glass hybridcomposite can be used for active vibration control, but from the results it is found that the Hybrid composite is comparativelymore efficient than the glass reinforced composite . REFERENCES [1]

[2]

Shafi Ullah Khan, Chi Yin Li,Naveed A. Siddiiqui, Jang-Kyo Kim. Vibration damping characteristics of Carbon fiber-reinforced composites containing multi-walled Carbon nanotubes. Journal of Composites Science and Technology, Vol. 71, 2011, pp. 1486-1494. Ioanac. Finegan. Gary.G.Tibbetts, Ronald, F.Gibson. Modeling and characterization of damping in carbon nano fiber / polypropylene

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