Investigation Of Friction Materials Of Brake Pad In .
IJSRD - International Journal for Scientific Research & Development Vol. 7, Issue 02, 2019 ISSN (online): 2321-0613Investigation of Friction Materials of Brake Pad in Automobile DiskBrakeJayesh Shah1 Siddharth Tirole2P.G Student 2Assistant Professor1,2Department of Mechanical Engineering1,2Silver Oak College of Engineering & Technology, India1Abstract— Nowadays, a composite material is used asreplacement of the conventional materials in Automobileindustries because of high strength to light weight properties,which reduces the overall vehicle weight withoutcompromising the strength and reliability. Compositematerials with higher specific stiffness, low weight, and highdamping capacity have greater torque capacity thanconventional drive shaft. The advanced composite materialssuch as carbon and glass with epoxy resin are widely usedbecause of their high specific strength and high specificmodulus. The aim of this work is to replace the conventionalasbestos brake pad of automobiles with an appropriatecarbon/glass composite brake pad. Study also includes thepreparation of composite brake pad for overall weightreduction, whereas the conventional asbestos brake pad haslots of issue related to environment. In this approach,optimum designed brake pad finite element model will beprepared in finite element commercial software ABAQUS.The noise, vibration and buckling analysis will be done whichare very much essential for friction materials like brake padExperiment also conducted on instrument to measure thevibration and mechanical properties of composite shaft.Keywords: Composite Materials, Brake Pad, ABAQUS,NoiseI. INTRODUCTIONAutomotive brakes are designed to slow and stop a vehicle bytransforming kinetic (motion) energy into heat energy. As thebrake linings contact the drums/rotors they create frictionwhich produces the heat energy. The intensity of the heat isproportional to the vehicle speed, the weight of the vehicle,and the quickness of the stop. Faster speeds, heavier vehicles,and quicker stops equal more heat. The geometric spaceavailable for the brakes in a car is however rather limited andconstrained by the dimensions of the wheel, so that new formsof brake design had to be developed and some of these newdesigns were more susceptible to generate unwanted noises.A typical modern floating caliper disk brake in shown infigure 1.2 in an artist’s view. The brake consists of a brakedisk, housing, piston, yoke and brake pads [7].Fig. 1: A typical floating calliper disk brakeA. Brake PadA brake pad consists of a friction material which is attachedto a stiff back plate. Figure 1.3 shows a brake pad attached toa back plate. Sometimes the friction material and back platetogether are called a brake pad. A brake pad usuallyincorporates slots on its face and chamfers at the ends. Figure1.4 shows different configurations of pads. A pad can havemore than one slot and it could be arranged in differentorientations.Fig. 2: An assembly of pad, back plate and shimIn the present study, an investigation of disc brakesqueal is performed by using the new complex eigenvaluecapability of the finite element (FE) software ABAQUSversion 6.4. This FE method uses nonlinear static analysis tocalculate the friction coupling prior to the complexeigenvalue extraction, as opposed to the direct matrix inputapproach that requires the user to tailor the friction couplingto stiffness matrix, Thus, the effect of non-uniform contactand other nonlinear effects are incorporated. A systematicanalysis is done to investigate the effects of systemparameters, such as the hydraulic pressure, the rotationalvelocity of the disc, the friction coefficient of the contactinteractions between the pads and the disc, the stiffness of thedisc, and the stiffness of the back plates of the pads, on thedisc squeal. The simulations performed in this work present aguideline to reduce the squeal noise of the disc brake system.II. LITERATURE REVIEWFriction-induced vibrations in automotive disc brakes are ofsubstantial interest for academic research as wells forindustry. The numerous customer complaints due to brakenoise cause high warranty costs in the automotive industry.To enable silent brakes to be developed, noise, vibration andharshness (NVH) engineers analyze these phenomena usingcomputational and experimental simulations as well asvehicle tests. In the automotive industry, computationalsimulations have become increasingly important because ofshorter product development processes as well as costreduction necessities.Conventional materials are replaced by compositematerials in so many fields due to their lightweight and easyprocessing. Nowadays hybrid composite drive shafts are alsoAll rights reserved by www.ijsrd.com2071
Investigation of Friction Materials of Brake Pad in Automobile Disk Brake(IJSRD/Vol. 7/Issue 02/2019/569)used in replacement of the steel and aluminum for thepreparation of these composites automotive parts. Syntheticfibers mainly carbon, glass, Kevlar have satisfactory strengthproperties coupled with relatively low cost, recyclability andbiodegradability and are being used in automotive industries,construction as well as in packaging industries with fewdrawbacks. The low density of fibers allows fabrication ofcomposites that gives good mechanical properties with a lowspecific mass. The increased interest in the use of fiber amongresearchers and technologist’s has been well known. Inautomotive industry brake squeal has become an importantcost factor because of customer dissatisfaction. In NorthAmerica up to one billion dollars p.a. were spent on noise,vibration and harness (NVH) issues. From the literature it isobserved that many researcher and automobile industries areworking on reduction of noise and vibration.S. Oberst and J. C.S. Lai studied the influence ofgeometrical parameters (namely, the number and location ofslots) of brake pads on brake squeal noise. Four differentbrakes lining geometry were prepared (i) basic configurationwithout any slot (ii) basic configuration modified with avertical slot in the mid-surfaces (iii) basic configuration withtwo slots and (iv) basic configuration with diagonals slot.This study reveals for the first time that severe nonlinearity isdirectly correlated with brake squeal and could be the reasonfor bad noise performance.T. Jearsiripongkul and D. Hochlenert studied themathematical-mechanical models for studying the brakesdynamics of modern passenger’s cars. A simplified model forthe dynamics of a floating calliper disk brake is presented.The model includes the brake disk, modelled as a flexiblerotating plate, calliper and brake pads. In the model all theprominent features of squeal are reproduced, such as e.g.independence of the frequency on the speed, etc. For amoderately wide frequency range (1-5 kHz) the transversevibration of the disk plays a significant role in squeal. Thepad stiffness and damping coefficient are modelled bydistributed nonlinear springs and linear plementation of the active squeal control goes along witha more profound understanding of brake squeal and a bettermodelling of the phenomena, ultimately leadingimprovements in the design of disk brakes.M. Nouby and K. Srinivasan investigated theinfluence of brake design parameters on brakes squeal. Theystudied by modifying the various structure of brake pad toreduce the squeal. The finite element method (FEM) is usedto simulate and predict the disc brake squeal using a complexeigenvalue analysis. An approach to examine the disc brakesqueal based on the complex eigenvalue analysis is proposedin which a positive real part indicates that the correspondingEigen mode is unstable and in turn squeal may occur. Fromthe several simulations done by complex eigenvaluesanalysis, it is observed that higher coefficient of frictionincreases the likelihood of squeal. The squeal can be reducedby decreasing the stiffness of the back plates of the pads. Thechamfer provided significant squeal reduction. To explain theeffect of slot configurations on squeal, the understanding ofthe pressure contact distribution between the pad and rotorare required.L. Rudolf examined the study of fade inconventional disc brakes results from two basic causes. (1)The brake pads overheat, reducing their coefficient of frictionwhich decreases braking ability, and (2) Excessive heat in thebrake pads is transferred via the hydraulic pistons to the brakefluid, which boils and produces bubbles in the brake lines.The full circle disc Brake resists these fade inducing causesby: (1) Distributing in-pad heat over a greater area andconducting heat both away from and through the brake padsinto the brake body structure to enable more efficient heatdissipation, and (2) isolating the hydraulic cylinder from thebrake pads so that direct heat is not transferred to the brakefluid.III. DESIGN AND ANALYSIS OF BRAKE PADGrey cast iron is used for maruti Suzuki ecco passengervehicle in disk brake rotor applications. The materialproperties of the grey cast iron is given by the supplier.A. Complex Eigenvalue AnalysisDuring braking operation, the friction between the brake padand the disc can induce a dynamic instability in the system.This instability can create noise, commonly known as squeal.In order to study the squeal propensity of the disc brake, astability analysis is performed on the model, and the unstablemodes are equated to a possible squealing occurrence. Thegoverning equation of the system isM u C u K u 0Where M, C, and, K are respectively the mass,damping and stiffness matrices. u is the displacement Vector.For friction induced vibration, it’s assumed that the forcingfunction is mainly contributed by the friction forcefluctuation between the rotor and friction material, the forcevector is linearized as F K f u Where, Kf is the friction stiffness matrix. Thegoverning equation is the obtained by combining M ü C u K K u 0 A complex eigenvalue algorithm is then used tosolve this eigenvalue problem in order to obtain eigenvaluesand eigenvectors in complex values.B. Dynamic, Temperature Displacement Explicit AnalysisA static analysis is used to determine the displacements,stresses, strains and forces in structures or components causedby loads that do not induce significant inertia and dampingeffects. A static analysis can however include steady inertialoads such as gravity, spinning and time varying loads.Disk brake rotor is developed using Creo parametric4.0 software using exiting dimension of Eecco disk brakerotor as given in table 4.4. All the dimension presented intable 4.4 is measured using vernier calliper. Figure 4.1 and4.2 shows the 3D model of disk brake rotor and 2D drawingof rotor respectively.Parameter nameDimensionOuter diameter of the rotor disc232 mmInner diameter of rotor dics125 mmHole diameter60 mmThickness of rotor disc17 mmCalliper piston diameter44 mmAll rights reserved by www.ijsrd.com2072
Investigation of Friction Materials of Brake Pad in Automobile Disk Brake(IJSRD/Vol. 7/Issue 02/2019/569)Mass of disc4.42 kgTable 4.4: Dimension of grey cast iron disk brake rotorFig. 3: 2D drawing of disk brake rotor in Creo 4.0A finite element model of the disc brake is generatedusing the finite element (FE) software ABAQUS version6.14. The brake model used in this study consists of the twomain components contributing to squeal: the disc and the padas shown in figure 4.2. The disc has a diameter of 232 mmand a thickness with typical value of 17 mm and is made ofgrey cast iron. The pair of brake pads, which consist offriction plates and back plates, are pressed against the disc inorder to generate a friction torque to slow the disc rotation.The friction materials are made of a kevlar-carbon organiccomposite friction material and the back plates are made ofsteel. The Dynamic, temperature displacement explicitanalysis has been done on ABAQUS 6.14 software byexplicit module as depicted in figure 4.3.Fig. 4.9: Applying Pressure on Both Side of Brake PadIn present study following mesh type and size hasbeen selected as demonstrated in figure 4.10. Meshing size isrefined at the hole where the disc brake rotor is fixed withwheel. Figure 4.11 shows the load applied on disk and padrespectively.Type of meshing: - C3D8TType of elements: - HexFig. 4.10: Disc mesh, showing refinement under pad contactareaMaximum load condition for disc brake rotor occursduring applying brake to de acceleration the moving vehicle.The disc brake rotor is connected with wheel by bolts behavesas a fixed body offering zero displacement and withstandduring braking operation.Fig. 4.8: Specifying Material Properties in ANSYS 18.1SoftwareIn this static step a rotational velocity is imposed onthe disc as a predefined field variable. This provides for themodeling of steady-state frictional sliding between twobodies that are moving with different velocities. The imposedvelocity of 123.65 rad/s corresponds to braking at lowvelocity. Figure 4.9 shows the pressure is applied on thepistons and housing in astatic analysis.IV. RESULTS AND DISCUSSIONIn the present FEA study total temperature distribution,friction dissipation and kinetic energy is considered forevaluating the results. The temperature distribution of theAll rights reserved by www.ijsrd.com2073
Investigation of Friction Materials of Brake Pad in Automobile Disk Brake(IJSRD/Vol. 7/Issue 02/2019/569)grey cast iron rotor and brake pad is calculated and thevalues obtained are the maximum temperature is 345 oC mand the minimum temperature is 20 oC as shown in figure4.12.Fig. 4.12: Temperature distribution of grey cast iron rotordisc and padThe brake is applied for 4.24 second by brake padwith help of hydraulic cylinder pressure on the grey cast ironrotor and vehicle will stop at distance of 141.55 m. Theobtained temperature distribution as shown in figure 4.13 duehigh friction between brake rotor and pad.The surface pressure distribution on the brakelinings after the application of pressure in is shown in figure4.15 and figure 4.16 The accuracy of the complex modecalculation depends strongly on the accuracy of the surfacepressure distribution between the pad and the disc.Fig. 4.15: Contact pressure distribution on the inboard liningFig. 4.16: Contact pressure distribution on the inboard liningV. CONCLUSIONFig. 4.13: Temperature distribution of grey cast iron rotordiscAs show in figure 4.14, when brake is applied highamount of heat is generated between rotor and brake pad for4.24 seconds. The generated heat is absorbed by rotor andgradually dissipated in environment.Disk brake squeal based on Friction-induced is investigatedusing the new function of ABAQUS version 6.4, whichcombines a nonlinear static analysis and a complexeigenvalue extraction method. The nonlinear effects can betaken into account in the preloading steps in order to moreaccurately model a deformed configuration at which acomplex eigenvalue analysis is performed. The systematicanalysis here shows that significant pad bending vibrationmay be responsible for causing the disc brake squeal and themajor squeal frequency is approximately 12 kHz for thepresent disc brake system. The effects of the friction betweenthe pads and the disc, the stiffness of the disc, and the stiffnessof the back plates of the pads, on disc squeal, are significant,but the effects of the hydraulic pressure and the angularvelocity of the disc on disc squeal are not obvious. The squealcan be reduced by decreasing the friction coefficient,increasing the stiffness of the disc, using damping material onthe back of the pads, and modifying the shape of the brakepads.Fig. 4.14: Equivalent elastic stress of grey cast iron rotordiscAll rights reserved by www.ijsrd.com2074
Investigation of Friction Materials of Brake Pad in Automobile Disk Brake(IJSRD/Vol. 7/Issue 02/2019/569)REFERENCES[1] Chogdu C and Sooick A, “Thermo-Elastic Analysis forChattering Phenomenon of automotive disk brake”,KSME Inter. J., 2001, 15, 569-579.[2] Thira J.and Daniel H, “Disk Brake Squeal: Modellingand Active Control”, Diploma Thesis, TU Darmstadt,Institute f ur Mecha, 2003.[3] Introduction to Brake Systems – Study Guide, MeliorGeneral Motors Corporation, Service Operations LicenseAgreement, 2004.[4] Pandya NA, “Computer Aided Design and Analysis ofDisc Brake Rotors Advances in AutomobileEngineering,” BITS Pilani, Dubai Campus, DubaiInternational Academic City (DIAC), Dubai, UAEAmrish, Adv Automob Eng, 2016, 5:2.[5] Swapnil R. Abhang, Bhaskar DP, “Design and Analysisof Disc Brake”, Inter. J. of Engin. Trends and Techn.(IJETT) –4- Feb 2014[6] Ameer S. and Lakshmi S,“Structural and ThermalAnalysis of Disc Brake Without Cross-drilled Rotor OfRace Car”, Inter. J. of Advan. Engg. Rese. and Studies,2012 , 2249-8974, 39-43[7] Phillip H. and Nick w. “Materials of brake rakes/brake-types/disc-brake.htm[8] Ibrahim RA, “Friction-Induced Vibration”, Chatter,Squeal and Chaos Part II, ASME Applied MechanicsReviews, 47, 1994, 227-259.[9] Chakraborty G, Jearsiripongkul T, Wagner UV andHagedorn P,”A New Model for Floating Calliper DiskBrake”, VDI-Tagung Reibung and Schwingungen inFahrzeugen und Anlagen, Hannover, November 26-27,2002.[10] Chowdhary HV, Bajaj AK and Krousgrill CM, “AnAnalytical Approach to Model Disc Brake System forSqueal Prediction”, Proceedings of ASME DETC 2001,Pittsburgh, September 9-12, 2001.[11] Ouyang H and Mottershead JE, “Friction-InducedParametric Resonances in Disc: Effect of A NegativeFriction-Velocity Relationship”, J. of Sound andVibration, 209(2), 1998, 251-264.[12] Lin SC, Guan CC, Bakar ARA, Jamaluddin MR,M.M.W. Harujan W, and Ghani BA, Disc brake squealsuppression through chamfered and slotted pad. Intern. J.of Vehicle Struc. and Syst., 3(1), 2011, 28–35.[13] Dai Y and Lim TC, “Suppression of brake squeal noiseapplying finite element brake and pad model enhancedby spectral-based assurance criteria”, Applied Acoustics,69(3), 2008,196 – 214.[14] Ghazaly NM and Faris WF, “Optimal design of a brakepad for squeal noise reduction using response surfacemethodology”, Inter. J. of Vehicle Noise and Vibration,8(2), 125–135, 2012.[15] Eriksson M, Bergman F, and Jacobson S, “On the natureof tribological contact in automotive brakes”, Wear,252(1-2), 2002, 26–36.[16] Lee K and Barber JR, “An experimental investigation offrictionally excited thermo elastic instability inautomotive disk brakes under a drag brake application”,J. of Tribology, 116(3), 1994, 409–414.[17] Hiller MB, “Correlation between parameters of thetribosystem and automotive disc brake squeal”, PhDthesis, University of Paderborn, 2006[18] Matozo L, Menetrier A, and Tamagna A. Analysis ofhigh damping underlayer materials for brake pads and itseffects on NVH performance. SAE Technical Paper,pages 01–3223, 2006.[19] Automotive Disc Brake Manual: The Complete Guide tothe Theory and Practice of Automotive Disc BrakingSystems. Techbook Series. Haynes, Somerset, 1998.[20] Matozo L, Menetrier A, and Tamagna A, “Analysis ofhigh damping underlay materials for brake pads and itseffects on NVH performance”, SAE Technical Paper,01–3223, 2006.[21] Automotive Disc Brake Manual: “The Complete Guideto the Theory and Practice of Automotive Disc BrakingSystems”, Tech book Series. Haynes, Somerset, 1998.[22] Balvedi AM and Gerges SNY, “Squeal noise in discbrakes and the influence of damping on the systemdynamic stability”, Acta Acustica united with Acustica,94(2), 2008, 254–264.[23] Kinkaid OM, Reilly O and Papadopoulos P,“Automotive disc brake squeal”, J. of Sound andVibration, 267(1), 2003, 105–166.[24] Chan D and. Stachowiak GW, “Review of automotivebrake friction materials”, Proc. of Inst. of mech. Engin.,Part D: J. of Automobile Engin. 218(9), 2004, 953-966.[25] Hong US, Jung SL, Cho KH, Cho MH, Kim SJ, and JangH, “Wear mechanism of multiphase friction materialswith different phenolic res
disc, and the stiffness of the back plates of the pads, on the disc squeal. The simulations performed in this work present a guideline to reduce the squeal noise of the disc brake system. II. LITERATURE REVIEW Friction-induced vibrations in automotive disc brakes are of industry. The numerous customer complaints due to brake
Lecture Note Chapter 6 1. Overview: friction force Friction forces are categorized as either static or kinetic. The coefficient of static friction μs characterizes friction when no movement exists between the two surfaces in question, and the kinetic coefficient μk characterizes friction where motion occurs. s coefficient of static friction k coefficient of kinetic friction
2 www.CarlisleCBF.com 1-855-403-9083 3 3 Table of Contents 4 About Carlisle Brake & Friction CARLISLE BRAKE & FRICTION AFTERMARKET ADVANTAGE (OE GRADE PRODUCTS) 10 On-Highway Friction 5 Aftermarket Capabilities 6-7 Markets Served 8 Brake Assemblies 9 Wet Friction Discs & Components 16-29 Wet Friction Discs & Compo
Friction Loss in a fire hose is governed by several rules: (Use FL for Friction Loss) Rule 1 – Friction loss varies with the quality of the hose. a. Write the variation formula for the 1st Friction Rule _ Rule 2 – Friction loss varies directly with the length of the hose. b.
While friction’s work is to oppose the relative motion and here if friction comes then relative motion will start and without friction there is no relative motion so both the block move together with same acceleration and friction will not come. mg A mg B a
ISO 8855 the longitudinal friction coefficient obtained on a locked wheel is called sliding braking force coefficient. Skid number The friction value as measured according to ASTM 274 which describes the friction measurement using a locked, smooth or ribbed standard test tyre. The skid number is the measured friction coefficient multiplied by 100.
Keywords: friction force, coefficient of friction, block-on-ring, ASTM G-77, wear. 1 Introduction Friction properties rank among many important material properties, which characterize the tribological behavior of materials that are in a sliding contact. Because of the sliding between two or more machine parts friction arises.
12.1 Forces . Forces . 12.1 Assessment . Question #2 List four types of friction 1. Static Friction 2. Sliding Friction 3. Rolling Friction 4. Fluid Friction 12.1 Assessment . Question #3 You
angular velocity. The results in the figures 12-14 are shown. Figure 12. DC motor angular velocity with different friction models – voltage supply – 2 V Closest to the measured angular velocity is model with Coulomb friction. The next is Stribeck friction. Interestingly, that viscous friction which is very similar to
