thermal black ppt

8/13/2019 THERMAL Black Ppt

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A

PROJECT

REPORTSUBMITTEDINPARTIALFULLFILMENT

FOR

THEAWARDOFDEGREEOFBACHELOROFTECHNOLOGY

IN

MECHANICALENGINEERING

BYCH.KRISHNACHAITANYAVARMA(07241A0309)

PADMANABHDAS(07241A0313)

PUNEETKUMAR.J(07241A0315)

THERMALANDSTRUCTURALANALYSISOFVENTEDANDNORMALDISC

DEPARMENTOFMECHANICALENGINEERING

GOKARAJURANGARAJUINSTITUTEOFENGINEERINGANDTECHNOLOGY

(AFFLIATEDTO

JAWAHARLAL

N

EHRU

TECHNOLOGICAL

UNIVERSITY)

HYDERABAD

20072011

BRAKEROTORS


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ACKNOWLEDGEMENT

Iexpressmygratitudetochairman,projectReviewCommittee,JNTUCollegeof

Engineering,

for

their

valuable

recommendations

and

for

accepting

this

project

work.

Iexpressmydeepsenseofgratitudetowardsmyableandacknowledgeguide,Mr.

Ra t n a ki r a n ,Asst.Professor,MechanicalEngineering,GRIET,Hyderabad,t o w h o mIowe

thecreditofbeingthemovingspiritbehindthisproject,wh o s e gu i d a n c eandconstant

inspirationledmetowardsitscompletion.

I

convey

my

sincere

thanks

to

Mr . K . G . K MU RT H Y ,

Head

of

the

Mechanical

Engineering

Department&Mr . P . S . V . K U RMA RA OProfessor,GOKARAJURANGARAJUINSTITUEOF

ENGINEERINGANDTECNOLOGY,HYDERABADforhiskindcooperationi n t h ecompletionof

theproject.

Atthisjuncture,Ifeelthat,IamgratefultoMr.PRADEEP,ORANGETECHNOLOGIES,

AMEERPET, HYDERABAD,forassistanceincompletionofprojectwork.

Finally,Iextendmysenseofgratitudetoallmyfriends,teachingandnonteachingstaff,

whodirectlyorindirectlyhelpmeinthisendeavor.

CH,K r i s h a n a c h a i t a n y a v a r m a ( 07241A 0309)

P a d m a n a b h D a s ( 07241A 0313)

P u n e e t ku m a r .J(07241A0315)


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ABSTRACT

Safety

aspect

in

automotive

engineering

has

been

considered

as

a n u m b e r

onepriorityindevelopmentofnewvehicle.Eachsinglesystemhasbeenstudiedand

developedinordertomeetsafetyrequirement.Insteadofh a vi n g a i rbag,goodsuspensionsystems,

goodhandlingandsafecornering,thereisonemostcriticalsysteminthevehiclewhichisbrakesystems.

Withoutbrakesysteminthevehiclewillputapassengerinunsafeposition.Therefore,itisamustforall

vehiclestohaveproperbrakesystem.Duetocriticalsysteminthevehicle,manyofresearchershave

conductedastudyonbrakesystemanditsentirecomponent.Inthisproject,theauthorhasconducted

astudyonventilatedandnormaldiscbrakerotorofnormalpassengervehiclewithfullloadofcapacity.

Thestudyismorelikelyconcernofheatandtemperaturedistributionondiscbrakerotor.

Steady

state

and

transient

response

has

been

conducted

through

the

heat

transfer

analysiswheretopredicttheworsecasescenarioandtemperaturebehaviorsofdiscbrakerotor.

Inthisstudy,finiteelementanalysisapproachedhasbeenconductedinorderto

identifythetemperaturedistributionsandbehaviorsofdiscbrakerotorinsteadystateandtransient

responses.An s y s i s h a sbeenusedasfiniteelementssoftwaretoperformthethermalanalysisonboth

responses.Bothresultshavebeencomparedforbetterjustification.Thus,bothresultsprovidebetter

understanding

on

the

thermal

characteristic

of

disc

brake

rotor

and

assist

the

automotive

industry

in

developingoptimumandeffectivediscbrakerotor.


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OBJECTIVEANDSCOPE

., :

, ,.

( )

. .


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Partsofdiscbrake

1.DISCCALIPERS

..( ,1996)..

,

.


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2.BRAKEPADS

. ( , 1980),

,

.

750 , - 950'~

0.25 0.5.

,

. ,

.


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3.BRAKEDISC/DISCBRAKEROTOR

Disc

brake

rotor

is

a

crucial

partinthebrakesystemwherethemainroleoftherotoristoreducetheheat

generated

by

dissipates

all

oftheheat.Inthatcase,

ventilateddiscbrakerotorismuchbetterthansolidrotorwhere

more

airflow

from

the

surroundingareatodissipateproducedheat.Figure2.9,

shows

the

internal

vanesallowairtocirculatebetween

twofrictionsurfacesoftherotors


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MODELLINGSOFTWARE

Therearedifferentsoftware'savailableformodelingsomeofthemare:

Solidworks

ProE

Ideas

Inventor

Mechanical

desktopUnigraphics

C a t i a v 5

CATIA

V5

(computer

aided

three

dimensional

interactive

a ppl i ca ti o n)a mul tiplatformCAD/CAM/CAEisusedasthemodelingtoolinthisproject


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CATIAV5

CATIAV5providesthepowerofparametricdesign.With

parametric,wedefinethemodalaccordingtothesizeand

positionalrelationshipofitsparts

1.INTRODUCTION

2.PART MODELLING

Manytechnicaldesignsconsistsofcomplexassembliesmadefromangular

shapedparts.Thistypeofdesignworkcanbemadea s i e r b ypartand

assemblymodelingcapabilitiesthatarewellintegrated.TheCATIAV5isa

3

D

parametric

solid

modeler

with

both

part

and

assembly

modeling

capabilities.YoucanseetheCATIAV5tomodelpiecepartsandthen

combinethemintomorecomplexassemblies.WithCATIAV5apartis

designedbysketchingitscomponentsshapesanddefiningtheirsizeshape

and

inter

relationships.

By

successfully

creating

these

fea t u r es y o uconstructthepartinabuildingblockfashion.SinceCATIAV5has

parametricfeatures,youcanchangeonefeatureandallrelatedfeatures

areautomaticallyupdatedtoreflectthechangeanditseffectsthroughout

thepart.Itcanbeusedtocreateangularshapedpart,tow h i c h 3 Dsurface

canbeappliedtocreatehybridpartsconsistingofmixtureofangularand

curvedshapes.Thisprovidestheabilitytocreatemodeld esi gn s wi t h

shapesofvaryingtypes


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3.GENERALMODELINGPROCESSFOREACHPART

P l a nthepart

C r e a t e

the

base

feature

C r e a t etheremainingfeatures

Analyze

the

part

Modifythefeaturesasnecessary

Assembly

modeling

FINITE ELEMENT ANALYSIS


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FINITEELEMENT

ANALYSIS

Thefiniteelementmethodisnumericalanalysistechniqueforobtaining

approximatesolutionstoawidevarietyofengineeringproblems. Becauseofits

diversityandflexibilityasananalysistool,itisreceivingmuchattentioninalmost

everyindustry.Inmoreandmoreengineeringsituationstoday,wefindthatitis

necessaryto

obtain

approximate

solutions

to

problem

rather

than exact

closed

form

solution.

INTRODUCTION

PROCEDUREFOR

ANSYS

ANALYSIS

Theprocedureforstaticanalysisconsistsof

thesemainsteps

Buildingthe

model

Obtainingthesolution

Reviewingtheresults


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BUILDTHEMODEL

MATERIALPROPERTIES

InthisstepwespecifythejobnameandanalysistitleusePREP7todefinetheelement

types,

element

real

constants,

material

properties

and

model

geometry

element

type

bothlinearandnon linearstructuralelementsareallowed.TheANSYSelementslibrary

containsover80differentelementtypes.Auniquenumberandprefixidentifyeach

elementtype.

E.g.

BEAM

94,

PLAN

71,

SOLID

96

and

PIPE

16E

Y o u n g.s mo d u l u s(EX)mustbedefinedforastaticanalysis.Ifweplantoapplyinertia

loads

(such

as

gravity)

we

define

mass

properties

such

as

density

(DENS).

Similarly

ifweplantoapplythermalloads(temperatures)wedefinecoefficientofthermalexpansion

SOLUTIONInthisstepwedefinetheanalysistypeandoptions,apply

loadsandinitiatethefiniteelementsolution.Thisinvolves

threephases:

PreprocessorphaseSolutionphasePostprocessorphase


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PRE

PROCESSOR

PHASE SOLUTION

PHASE

POST

PROCESSOR

GEOMETRYDEFINITION ELEMENTMATRIXFORMATION POSTSOLUTIONOPERATION

MESH GENERATION OVERALLMATRIXT RIA NG ULAR IZA TIO N P OSTDATAPRINTOUTFORREPORTS

MATERIAL WAVEFRONT POSTDATA

DEFINITIONS SCANINGPOSTDATADISPLAY

CONSTRAINDEFINITIONS DISPLACEMENT,STRESS,ET.,

LOADDEFINITIONS CALCULATION

MODELDISPLAY

ThefollowingTable showsthebriefdescriptionofstepsfollowedineachphase


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FINITEELEMENTGENERATIONThemaximumamountoftimeinafiniteelementanalysisisspent

on

generating

elements

and

nodal

data.

Pre

processor

allows

the

usertogeneratenodesandelementsautomaticallyatthesame

timeallowingcontroloversizeandnumberofelements.There

arevarioustypesofelementsthatcanbemappedorgenerated

on

various

geometric

entities.

The

elements

developed

by

variousautomaticelementgenerationcapabilitiesofpreprocessorcanbe

checkedelementcharacteristicsthatmayneedtobeverified

beforethefiniteelementanalysisforconnectivity,distortion

indexetc.Generally,automaticmeshgeneratingcapabilitiesof

preprocessorareusedratherthandefiningthenodesindividually.Ifrequirednodescanbedefinedeasilybydefiningtheallocations

orbytranslatingtheexistingnodes.Alsoononecanplot,delete,

orsearchnodes.

BOUNDARYCONDITIONSANDLOADING

Aftercompletionofthefiniteelementmodelithastoco n st r a i n a n d

loadhastobeappliedtothemodel.Usercandefineconstraints

and

loads

in

various

ways.

All

constraints

and

loads

are

assigned

set

ID.Thishelpstheusertokeeptrackofloadcases.


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MODELDISPLAY

During

the

construction

and

verification

stages

of

the

model

it

may

be

necessary

to

view

itfromdifferentangles.Itisusefultorotatethemodelwithrespecttotheglobalsystem

andviewitfromdifferentangles.Preprocessoroffersthiscapabilities.Bywindowing

featurepreprocessorallowstheusertoenlargeaspecifica r e a o f themodelforclarity

and

details.

Pre

processor

also

provides

features

like

smoothness,

scaling,

regions,

active

set,etcforefficientmodelviewingandediting.

MATERIALDEFECTIONS

Allelementsaredefinedbynodes,whichhaveonlytheirlocationdefined.Inthecase

of

plateandshellelementsthereisnoindicationofthickness.Thisthicknesscanbegiven

aselementproperty.Propertytablesforaparticularpropertyset1Dhavetobeinput.

Differenttypesofelementshavedifferentpropertiesfore.g.

Beams:Crosssectionalarea,momentofinertiaetc

Shell:

Thickness

Springs:Stiffness


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POSTPROCESSORIt is a powerful user- friendly post- processing programusing interactive colour graphics.

It has extensive plotting features for displaying the resultsobtained from the finite element analysis. One picture ofthe analysis results (i.e. the results in a visual form) canoften reveal in seconds what would take an engineer hourto assess from a numerical output, say in tabular form. Theengineer may also see the important aspects of the results

that could be easily missed in a stack of numerical data.Employing state of art image enhancement techniques,facilities viewing of:

Contours of stresses, displacements, temperatures etc.Deform geometric plots Animated deformed shapes Time-history plots Solid sectioning Hidden line plot Light source shaded plot

Boundary line plot etc.

The entire range of post processing options of differenttypes of analysis can be accessed through thecommand/menu mode there by giving the user addedflexibility and convenience.


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THERMALANALYSISAthermalanalysiscalculatesthetemperature

distributionand

related

thermal

quantitiesinbrakedisk.Typicalthermal

quantitiesare:

1.Thetemperaturedistribution

2.Theamountofheatlostorgained

3.Thermalfluxes

Typesofthermalanalysis

1.Asteadystatethermalanalysisdeterminesthetemperature

distributionandotherthermalquantitiesundersteadystateloading

conditions.Asteadystateloadingconditionisasituationwhere

heatstorageeffectsvaryingoveraperiodoftimecanbeignored.

2.Atransientthermalanalysisdeterminesthetemperature

distributionandotherthermalquantitiesunderconditionsthat

varyingoveraperiodoftime.


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PLANNINGTHEANALYSIS

In this step a compromise between the computer time andaccuracyoftheanalysis ismade.Thevariousparametersset inanalysis

are

given

below:

Thermalmodeling

Analysistype.thermalhmethod.

SteadystateorTransient?Transient

Thermalor

Structural?

Thermal

Propertiesofthematerial?Isotropic

Objectiveofanalysistofindoutthetemperaturedistributioninthebrakedisk

whenthe

process

of

braking

is

done.

UnitsSI


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Structuralanalysisisthemostcommonapplicationofthefinite element

analysis.The

term

structural

implies

civil

engineering

structure

such

as

bridge

andbuilding,butalsonaval,aeronauticalandmechanicalstructuresuchasship

hulls,aircraftbodiesandmachinehousingaswellasmechanical components

suchaspiston,machinepartsandtools.

STRUCTURALANALYSIS

Typesofstructuralanalysis:

Staticanalysis

Modalanalysis

Harmonicanalysis

Transientdynamicanalysis

Spectrumanalysis

Buckling

analysis Explicitdynamicanalysis

TheseventypesofstructuralanalysesinANSYS.Onecanperform the

followingtypes

of

structural

analysis.

Each

of

these

analysis

types

are

discussedasfollows:

MODELING AND ANALYSIS


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MODELINGANDANALYSIS

Itisverydifficulttoexactlymodelthebrakedisk,inwhichtherearestill

researchesare

going

on

to

find

out

transient

thermo

elastic

behavior

of

disk

brake

duringbrakingapplications

1.Thediskmaterialisconsideredashomogeneousandisotropic.

2.Thedomainisconsideredasaxissymmetric.

3.Inertia

and

body

force

effects

are

negligible

during

the

analysis.

4.Thediskisstressfreebeforetheapplicationofbrake.

5.Brakesareappliedontheentirefourwheels.

6.Theanalysisisbasedonpurethermalloadingandvibrationand thusonlystresslevel

due

theabove

said

is

done.

The

analysis

doesnotdeterminethelifeofthediskbrake.

7.Onlyambientaircoolingistakenintoaccountandnoforced

Convectionistaken.

8.Thekineticenergyofthevehicleislostthroughthebrakedisksi.e.

noheatlossbetweenthetyre andtheroadsurfaceanddeceleration

isuniform.

9.Thediskbrakemodelusedisofsolidtypeandnotventilated one.

10.Thethermalconductivityofthematerialusedfortheanalysisis

uniformthroughout.

11.Thespecificheatofthematerialusedisconstantthroughoutand

doesnotchangewithtemperature.

DEFINITION OF PROBLEM DOMAIN


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DEFINITIONOFPROBLEMDOMAINDuetotheapplicationofbrakesonthecardiskbrakerotor,heat

generationtakesplaceduetofrictionandthisthermalfluxhas tobe

conductedand

dispersed

across

the

disk

rotor

cross

section.

The condition

ofbrakingisverymuchsevereandthusthethermalanalysishas tobe

carriedout.Thethermalloadingaswellasstructureisaxissymmetric.

Henceaxissymmetricanalysiscanbeperformed,butinthisstudywe

performed3D

analysis,

which

is

an

exact

representation

for

this

thermal

analysis.Thermalanalysisiscarriedoutandwiththeaboveloadstructural

analysisisalsoperformedforanalyzingthestabilityofthestructure.

The3dmodelofthesolidtypebrakeisdoneinCATIAandconvertedinto

Parasolid

file.

Fig.solidtypediskbrake3Dmodelisometricview


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Fig.solidtypediskbrake3Dmodelfrontview

Fig.

solid

type

disk

brake

3D

model

wireframe


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SOLID90isahigherorderversionofthe3Deightnodethermalelement(SOLID70).The

elementhas20nodeswithasingledegreeof

freedom,temperature,ateachnode.The20

node

elements

have

compatible

temperature

shapesandarewellsuitedtomodelcurved

boundaries.The20nodethermalelementis

applicabletoa3D,steadystateortransient

thermal

analysisThegeometry,nodelocations,andthe

coordinatesystemforthiselementareshown

inFigure"SOLID90Geometry".Theelementis

definedby20nodepointsandthematerial

properties.

A

prism

shaped

element

may

be

formedbydefiningduplicateK,L,andS;Aand

B;andO,P,andWnodenumbers.

SOLID90ElementDescription


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face

1

(J

I

L

K),

face

2

(I

J

N

M),

face

3

(J

K

O

N),

face4(KLPO),face5(LIMP),face6(MNOP)

HG(I),HG(J),HG(K),HG(L),HG(M),HG(N),HG(O),HG(P),HG(Q),HG(R),

HG(S),HG(T),HG(U),HG(V),HG(W),HG(X),HG(Y),HG(Z),HG(A),HG(B)

SOLID90InputSummary

Nodes

I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,A,B

Degrees

of

Freedom

TEMP

MaterialProperties

KXX,KYY,KZZ,DENS,C,ENTH

SurfaceLoads

C o n v e c t i o n o r

Heat

Flux

(but

not

both)

and

Radiation

(using

Lab

=

RDSF)

BodyLoads

HeatGenerations


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Fig.solidtypediskbrakemeshmodel Fig.solidtypediskbrakemeshmodelisometricview

Totalnumberofelements=39800

Totalnumberofnodes=98104


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APPLYINGTHEBOUNDARYCONDITIONSInthermalandstructuralanalysisofdiskbrake,wehave

to

apply

thermal

and

boundary

conditions

on

3D

disk

modelofdiskbrake.

THERMALBOUNDARYCONDITIONSAsshowninFig.amodelpresentsathreedimensional

solid

disk

squeezed

by

two

finite

width

friction

material

calledpads.Theentiresurface,S,ofthediskhasthree

differentregionsincludingS1andS2.OnS1heatfluxis

specifiedduetothefrictionalheatingbetweenthepads

anddisk,andS2isdefinedfortheconvectionboundary.

The

rest

of

the

region,

except

S1

U

S2,

is

either

temperaturespecifiedorassumedtobeinsulated:the

innerandouterrimareaofdisk.

Fig.ThermalmodelofDiskbrake


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Fig.Temperatureboundaryconditionof77degreesCappliedonsolidtype

DiskbrakeFig.ConvectionboundaryconditionappliedonsolidtypeDiskbrake

Material

Properties

on

Pad

and

Disk

Thermalconductivity,K( w / m k )

Density,r (kg/m3)

1800

Specificheat,c(J/Kgk) 1.88

Poissons

ratio,

v 0.3

Thermalexpansion, ( 1 06/k) 0.3Elasticmodulus,E(GPa) 50.2

Coefficientoffriction, 0.2

Fig.TemperaturedistributiononsolidtypeDiskbrakeonthefront

side


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Fig.TemperaturedistributiononsolidtypeDiskbrakeontherearside

Fig.TemperaturedistributiononsolidtypeDiskbrakealongthe

thickness

Fig.GraphicalrepresentationofTemperaturedistributiononsolidtypeDisk

brake

along

the

thickness

STRUCTURALANALYSISNORMALDISCBRAKEROTOR


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STRUCTURALBOUNDARYCONDITIONS

Sincetheaxissymmetricmodelisconsideredallthenodesonthehubradius

arefixed.Sothenodaldisplacementsinthehubbecomezeroi.e.inradial,

axialandangulardirections

Fig.StructuralboundaryconditionappliedonsolidtypeDiskbrake

Fig.TemperaturedistributionisappliedasThermalloadsonsolidtype

Diskbrakefromthethermalanalysis

RESULTS


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RESULTS

Fig.

Total

deflection

of

solid

type

Disk

brakeFig.DeflectioninXdirofsolidtypeDiskbrake


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Fig.DeflectioninYdirofsolidtypeDiskbrake

Fig.DeflectioninZdirofsolidtypeDiskbrake


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Fig.

V o n M i ses st r ess

on

solid

type

Disk

brake

Fig.XdirstressonsolidtypeDiskbrake


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Fig.

Y

dir

stress

on

solid

type

Disk

brake

Fig.ZdirstressonsolidtypeDiskbrake

Tooptimizetheabovediskbrakeacomplicatedmodelofventilateddiskbrakeistaken


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andtherebyforcedconvectionisconsideredintheanalysis

Fig.Ventilatedtypediskbrake3Dmodelisometricview Fig.Ventilatedtypediskbrake3Dmodelisometricviewontherearside

Fig.Ventilatedtypediskbrake3Dmodelfrontview Fig.Ventilatedtypediskbrake3Dmodelinwireframe

CREATINGAFINITEELEMENTMESHFOEVENTEDROTOR


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APPLYINGTHE

BOUNDARY

CONDITIONS

Fig.Ventilatedtypediskbrakemeshmodelinisometricview Fig.Ventilatedtypediskbrake3Dmodelinshowingthevents

Fig.Temperatureboundaryconditionof77degreesCappliedonVenttype

Diskbrake Fig.ConvectionboundaryconditionappliedonVenttypeDiskbrake

Results


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Fig.TemperaturedistributiononVenttypeDiskbrakeonthefrontside Fig.TemperaturedistributiononVenttypeDiskbrakeontherearside

Fig.TemperaturedistributiononVenttypeDiskbrakealongthethicknessFig.GraphicalrepresentationofTemperaturedistributiononventtypeDis

brakealongthethickness

STRUCTURALANALYSISFORVENTEDDISCBRAKEROTOR


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Results

Fig.StructuralboundaryconditionappliedonVenttypeDiskbrake Fi g.TemperaturedistributionisappliedasThermalloadsonVenttypeDiskbrake

from

the

thermal

analysis

Fig.TotalDeflectiononVenttypeDiskbrake Fig.DeflectioninXdirofVenttypeDiskbrake


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Fig.DeflectioninYdirofVenttypeDiskbrake Fig.DeflectioninZdirofVenttypeDiskbrake

Fig.V o n M i s es s t r es sonVenttypeDiskbrake Fig.XdirstressonVenttypeDiskbrake


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Fig.

Y

dir

stress

on

Vent

type

Disk

brake

Fig.ZdirstressonVenttypeDiskbrake

CO C S O S


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SolidType VentilatedType

TotalDeflectionin(mm) 2.35 1 0.248

Vonmises Stress 2.26E+1 2 2.17 E+06

CONCLUSIONSThepresentstudycanprovideausefuldesigntoolandimprovethe

brakeperformance

of

disk

brake

system.

From

the

below

Table

we

cansaythatallthevaluesobtainedfromtheanalysisarelessthan

theirallowablevalues.Hencethebrakediskdesignissafebasedon

thestrengthandrigiditycriteria.Comparingthedifferentresults

obtainedfrom

analysis.

It

is

concluded

that

ventilated

type

disk

brakeisthebestpossibleforthepresentapplication.


42/42

thermal black ppt

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