brake disk analysis

7/23/2019 Brake Disk Analysis

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Disc brake DesignAnd Analysis



Brake Disc Design and analysis is a

project through which we have aimedto achieve an understanding and

learning of development of a productstraight from its conception to

manufacturing, encompassing all thestages such as Initial Calculations,Designing, aterial !election and

anufacturing considerations"



Targets of the Project

Try to simulate the various physical and thermalloads on the brake disc.

To study various calculations and contributingfactors on selection of a brake disc

To research further on all the included topics andsuggest improvements in the design and materialsused

To study the kinds of loads and stresses of a brakeunder use.

To study materials generally used formanufacturing of brake discs in the industry.

To estimate ways to better research the variation

of results found during analysis and actual use.



Brake Calculations

What we want to achieve through theBrake Calculation ?



B! for Brake Calculation



#ce ee o ra eCalculation



%esult of Brake Calculation

#rom the calculations, $ressure on Disc part between padsfound is %"&' ( )*& +m-

.he surface temperature in a single stop was found to be/&'0, and by estimating for multiple stops, it reaches up to

&**0elvin

Brake .or1ue on the front disc was found throughcalculations to be 23'"& +"m



&s on braking all the kinetic energy is converted into heat energy'which is generated at the brake pad'disc interface we will distributethis as heat power supplied at the disc pad interface(only at the partof disc in contact with pads)

We*ll determine kinetic energy by assuming a given speed+ lets say,-ms to be brought to a complete stop given by/.-0mass0velocity1,.. The ma# coe2cient of friction would provideus with deceleration hence the stopping time+ so we*d know how thepower is distributed over time.

We*d analy3e the disk under this heat power provided as a 4u# onlyfor the while the brakes are applied+ and convection throughout therest of the disk surface so it is simultaneously also cooling re4ectinga real scenario. 5nitial temperature is assumed to be same as thesurroundings+ the convection coe2cient used is an estimate and

we*ll look to calculate a closer value through C! simulation

Thermal &nalysis of Brake!isc



Thermal BoundaryConditions 6

Temperature &llows for the de7nition of a temperature on a certainentity or body

Convection applies a convection boundary condition to the selectedfaces. The convection coe2cient and ambient temperature arespeci7ed and the heat lost due to convection is calculatedautomatically.

8eat lu# &pplies some amount of heat into a face per unit area.

• 8eat lu# &pplies some amount of heat into a face per unit area.

8eat Power &pplies some amount of heat to a verte#+ edge+ face orcomponent. %adiation &llows surface'to'surface or surface'to'ambient radiation.

5n our model+ we will apply convection to all faces because all of thefaces will be e#posed to the air. 5n addition+ we will apply a heatpower to the faces that the brake pads touch.



$creenshot of the &nalysis 6



5deal Properties for Brake!isc$roperties 4usti5cation for 6e1uired $roperty

8ardnessBrake disc is generally e#pected to have highhardness for slower wear rates. The hardnessgenerally re9uired is about '-7'2 86C

Temper $oftening&s in braking applications the temperaturereached are often as high as /** degrees

temper softening might lead to warping anddeformation of disc under the physical loads.

$trength The strength of the material should be high9 /%* $a : to withstand the loads and this ismeasured in terms of its yieldcompressive

strength

atigue $trength&s it is a component that is supposed to workfor a long time of application depending on theuse+ its e#pected to work without failure forlarge number of cycles. This is measured interms of creep strength.



Physical Properties of :eneral Purpose$teels 6



Carbon Ceramic

.;$<! $6=$<6.I<! $6=B><! I$6=?<<+.

CC'$iC is aCarbon 7ber

phase added toa $ilicon Carbide

matri#.

• 5ncreasedstrength withlower density.

•&bility to

withstand hightemperatureswithout failure.

•;ow Coe2cientof Thermal

"#pansion.

•Can withstandsurface Temperatures of<///C with

minimal wear.

• 5ne2cient andmuch weaker if

used in coldcondition.

•

Cracking onoccur on thesurface.

• ;ow demandfor high

performancebrakes.

• "#pensive

• =ake thematerial with ahigher ceramiccontent in order

to achieve

higher surfacetemperature.

• >se of morethermally

conductive 7bre

in the ceramicmatri# in orderto have highperformance.



&luminum =atri# Composites

.;$<! $6=$<6.I<! $6=B><! I$6=?<<+.

&luminum=atri#

Composite

( &=C )==C %otor

• ;ight weight( /@ weightreduction as

compared toCast 5ron ).

• Better heatconductivity.

0 &bility todistribute wearuniformly overthe surface.

• ;owercoe2cient offriction and

wear rates thanclassical steel

discs.

• 8ighly costlyas well as

di2cult tomanufacture.

• %educe brakenoise and wear

• 5mprovesunsprung masswhich leads tobetter vehicle

acceleration andmaneuverability.



.;$<! $6=$<6.I<! $6=B><! I$6=?<<+.

CC'$iC is aCarbon 7ber

phase added toa $ilicon Carbide

matri#.

• 5ncreasedstrength withlower density.

•&bility towithstand hightemperatureswithout failure.

•;ow Coe2cientof Thermal"#pansion.

•Can withstandsurface Temperatures of<///C withminimal wear.

• 5ne2cient andmuch weaker if

used in coldcondition.

• Cracking onoccur on the

surface.

• ;ow demandfor high

performancebrakes.

• "#pensive

• =ake thematerial with ahigher ceramiccontent in order

to achievehigher surfacetemperature.

• >se of morethermally

conductive 7brein the ceramicmatri# in orderto have highperformance.

$tainless $teel



Comparison of diAerent

=artensitic $teel



>niversal Testing =achine

• &s an e#ercise to 7nd if there

is any change in themicrostructure due to multipleloading and unloading cyclesof the brake disc ( thermal

and physical )+ we tested aspecimen from a brake disc ofmotorbike which had done/+///kms.

• 5t was tested for its ield$trength and Percentage"longation in the >T= in the$D= lab of our college and theresults were E//=Pa ield$trength and ,/@ Percentage

"longation indicated it to be



Conclusion

Producing a high performance vehicle one must consider thecomponents+ the materials used and the purpose of the vehicle. Thedisc brakes on a racecar emphasi3e diAerent properties than amotorcycle+ or airplane. & racecar would be focused on high thermalresistance since there is a great amount of friction compared to amotorcycle would focus in weight reduction since it doesn*t produce asmuch heat. or optimal performance and e2ciency there must be abalance of mechanical properties of the material used+ it*s performanceand cost. 5n a racecar like the one selected for our project+ theperformance bene7t due to using carbon ceramic discs does not justifyits cost+ also the heat generated is not enough for a signi7cant

advantage. &luminium matri# provide insu2cient friction coe2cient+and their weight advantage is nulli7ed due to need of a larger caliper.8ence our choice would be to use a artensitic steel which canprovide good performance(coe2cient of friction and heat dissipation).



uture Prospects and urther$tudy 6

We*ll aim at optimi3ing weight and convection rates through iterationsof simulations using diAerent designs adding ribs or holes+ varyingthem in number and diameter to reach an optimum solution for theselected test vehicle.

We had stumbled upon some research on using a closer to real value

of convection through a C! simulation of air around the brake disc.5*m personally in contact with totalsim.co.uk. 5t would lead to a closervalue of the convection coe2cient that would result in a moreaccurate result.

We have gone through a number of research papers on the 5dealbrake disc materials+ its something we might look into. We havescouted for various active temperature sensing and data loggingunits+ 5*d attached a few pdf*s of some products along by motec andte#ense



Thank ou

Presented By 6

&nanya Bharadwaj &shwani $aini Chanchal Frishna ,k<,&"</ ,k<,&"<G ,k<,&",

brake disk analysis

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