International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056

Volume: 08 Issue: 04 | Apr 2021 www.irjet.net p-ISSN: 2395-0072

DESIGN AND ANALYSIS OF DISC BRAKE ROTOR FOR ALL TERRAIN

VEHICLES
VINODKUMAR V1, GOWRI SHANKAR M2, KAILASH K3, HARIHARAN J4, KAMALESH5

1Asst.Professor, Department of Mechanical Engineering, Panimalar Institute of Technology, Chennai, India.

2-5UG scholar, Department of Mechanical Engineering, Panimalar Institute of Technology, Chennai, India.

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Abstract: A disc brake is a device by means of systems are designed to reduce the speed and stop a
which artificial frictional resistance is applied to the moving. This is done by causing friction at the wheels.
rotating member, in order to stop the motion of a Friction converts the kinetic energy into heat. The
machine or a vehicle. Brake fading and thermo-elastic greater the pressure applied to the objects, the more
deformation of brake rotor is frequently found friction & heat produced, & the sooner the vehicle is
problem in custom made rotors. Due to combined brought to a stop. Kinetic friction acts in the brakes
effect of mechanical forces and temperature rise, the and static friction between the tire and road to slow
rotor deforms. This problem is very severe in All the vehicle. Most brakes commonly use friction
Terrain Vehicles (ATVs). To avoid this problem, pre- between two surfaces pressed together to convert the
manufacturing analysis of rotor is must. This project kinetic energy of the moving object into heat, though
deals with the structural and thermal analysis of other methods of energy conversion may be
rotor disc of disc brake BAJA SAE CAR through finite employed. For example, regenerative braking
element analysis approach using ANSYS software. converts much of the energy to electrical energy,
The rotor discs are commonly manufactured of grey which may be stored for later use. Other methods
cast iron. The SAE also recommend grey cast iron for convert kinetic energy into potential energy in such
various applications. SS410 is also suitable for stored forms as pressurized air or pressurized oil.
condition of parameters of rotor disc like Disc Eddy current brakes use magnetic fields to convert
diameter, Pattern & Material composition. The kinetic energy into electric current in the brake disc,
modelling of rotor disc is done in Solidworks 2017 fin, or rail, which is converted into heat. Still other
software. Analysis is done by using ANSYS 17.2 braking methods even transform kinetic energy into
different forms, for example by transferring the
KEYWORDS: Structural and Thermal analysis, SAE BAJA,
energy to a rotating flywheel.
Rotor Disc, Grey Cast Iron, SS 410, Finite Element Analysis

INTRODUCTION DISC BRAKE

A brake is a mechanical device that inhibits motion A disc brake is a type of brake that uses the calipers
by absorbing energy from a moving system. It is used to squeeze pairs of pads against a disc or rotor to
for slowing or stopping a moving vehicle, wheel, axle, create friction. This action slows the rotation of a
or to prevent its motion, most often accomplished by shaft, such as a vehicle axle, either to reduce its
means of friction. It is an energy converting rotational speed or to hold it stationary. The energy
mechanism that converts vehicle movement into heat of motion is converted into waste heat which must be
while stopping the rotation of the wheels. All braking dispersed.

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Brake disc (Rotor) come into their original shape. At this time retraction
spring pushes the brake 5 pads to their original
The brake disc (rotor) is the rotating part of a wheel's
position. The return spring in master cylinder
disc brake assembly, against which the brake pads
assembly pushes the master cylinder piston back into
are applied. Some are simply solid, but others are
its original position and allows the fluid to flow back
hollowed out with fins or vanes joining together the
to reservoir via hosepipe and master cylinder bore.
disc's two contact surfaces. The weight and power of
the vehicle determines the need for ventilated discs. CALCULATION OF BRAKE DISC
WORKING PRINCIPLE OF DISC BRAKE
When a brake lever or pedal is pressed, the push rod
which is connected to lever or pedal and master
cylinder piston pushes the master cylinder piston.
This movement allows the master cylinder piston to
slide and push the return spring inside the bore of
master cylinder, which generates pressure in
reservoir tank. At this moment a primary seal allows
the brake fluid of reservoir tank to flow over it into
the brake hosepipes. A secondary seal ensures that
the brake fluid does not go other side.Then the fluid
enters in to cylinder bore of caliper assembly via
brake hosepipes and pushes the caliper piston or
pistons. At this time the piston ring moves in rolling .
shape with piston. Then the caliper piston pushes
brake pad. This movement causes brake pads to stick
with brake disc which creates friction and stops the
brake disc/rotor to rotate. This way disk brake
system stops or slows down the vehicle.

Static Weight Distribution :

Taking moment about rear axle,

Fzf x l = W x lr
When the brake lever or pedal is released the piston
ring pushes the calliper piston back to cylinder bore Fzf = (W x lr) / l = (2600 x 58)/142.2
of calliper till both, calliper piston and piston ring Fzf = 106.05 Kg
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(Therefore, static weight distribution is in the ratio Validation of Brake Torque Requirement
40:60)
The braking torque should be more than the torque
Dynamic Weight Distribution: produed in order for braking.

Consider ∆dyn as dynamic weight distribution, this Force at master cylinder:

dynamic weight is loaded to front axle by unloading
The applied force is transferred through the push
from rear axle during braking. Taking moment of the
rod to master cylinder
forces acting on the vehicle about the centre of
gravity. Fmc = PF x PR = 250 x 6

We get dynamic weight equation as follows, = 1500 N.

∆dyn = (h/l) x (a/g) x W Force at Calliper Piston:

It is the normal force acting on the disc. It is called as
= (h/l) x µr x W
clamping force. The force applied traveled to caliper
Since Traction force (F= µrmg) and Force produced through brake fluid. According to Bernoulli’s theorem
by the vehicle (F=ma) should be equal. pressure at master cylinder and calliper piston is
equal.
∆dyn = (75/142.2) x 0.65 x 260
Fc = Pmc x ac = ( Fmc x ac ) / amc
∆dyn = 89.14 Kg
= (1500 x 9.08 x 10-4 ) / 2.85 x 10 -4
= 4778.94 N
Front Axle Reaction Force:
Considering Brake fluid loss, leverage loss, assume
It is equal to normal force acting on the front axle efficiency as 80%.
between road and vehicle.
Fc = 3822.68 N
Fzf + ∆dyn = 106.05 + 89.14
Braking Force on Discs:
= 195.2 Kg (1914.81 N)
It is the frictional force between pad and disc. This
Front Axle braking Force: force is acting on both side of the disc
It is the frictional force acting on the front axle
Fc(disc) = 2 ( µd x Fc ) = 2 (0.40 x 3822.68)
between road and tyre.
= 3058.144 N.
Fxf = Fzf, ∆dyn x µr = 1914.81 x 0.65
Torque Generated:
Fxf = 1244.62 N
Torque generated by the disc: Tfront = Fc(disc) x Reffective

Txf = Fxf x r = 1244.62 x 0.2794 Where,

= 347.75 ~ 350 Nm Reffective = (Disk diameter/2) - (Calliper
Torque produced by the single front wheel (or disc) diameter/2)
Txf = 175 Nm = (160/2) – (34/2)

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= 63 mm Braking Time:
Tfront = 3058.144 x 0.063 Using velocity as a function of acceleration equation v
= 192 Nm ~ 200 Nm = u + at

Thus, Braking torque required > Braking torque Deceleration = µr g = 0.65 x 9.81
(front). Thus, the expected disc diameter is validated = 6.3765 m/s 2
for design..
Acceleration = -6.3765 m/s 2
Heat Flux Entering the Rotor Hence,
The following assumptions are made before 0 = 16.67 + (-6.3765 x t)
calculations:
t = 2.615 s
1. Whole kinetic energy transferred into heat energy
Power generated on a disc:
through rotor
Heat generated per time is called Power (Heat flow).
2. Heat transfer through the tyre is neglected
P = E / t = 36125.557/2.615
3. Heat transfer through the pad is neglected
= 13814.75 J/s
4. Approximated swept area is used to calculate heat
flux As 75% of the kinetic energy is been distributed to
the front wheels power generated in one rotor
Abbreviations:
= (P x 0.75) / 2 = (36125.557 x 0.75)/2
E = Heat Energy
=5180.53 J
u = Initial Velocity
Heat flux generated:
v = Final Velocity
Flow of energy per unit of area per unit of time is
t = Braking Time
called Heat flux (Heat flux density).
P = Power (Heat Flow)
Heat flux entering disc is through the swept area of
A = Swept area of pad on the disc pad.
Φ = Heat Flux Φ = P/2A
Maximum Heat Energy: = 13547.08/ (2 x 0.0221)
The kinetic energy produced is wholly transferred to =117467.82 w/m2 (for 170 mm)
disc.
Maximum heat energy(E) = maximum kinetic energy
E = 0 .5 x mv 2 = 0.5 x (260 x 16.672 )
= 36125.557 J

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Design of Rotor (Brake disc)

The design part of the project was done in
Solidworks 2017.
The design is done with following specification
Specifications
Disc Inner Diameter = 60 mm
Disc Outer Diameter = 160 mm THERMAL ANALYSIS
Thickness = 4 mm Heat flux
Diameter of hole for bolt = 9 mm The heat flux is enter into disc through the area
With the above specification , the rotor is designed swept by the pad which was imprinted in the disc.
Heat flux is applied to both side of the disc.
along with the two different patterns
Slot 1 = Forward Curved Fin
Slot 2 = fin with small hole in outer range
In both the slots the fins are ranged around 16-17 in
such a way that the surface area is approximately
equal between different patterns

CONVECTION
we assumed heat transfer coefficient as
220 w/moC for 170 mm
Meshing
Convection takes place at all the surface of the rotor,
Element size - 2mm hence whole body is selected
Span angle center - fine
Smoothing – high

Radiation
Thermal radiation generates from the emission of
electromagnetic waves..

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It depends on the parameter called emmisivity taken

as 0.8 for both material .
The whole body Is taken for radiation.

RESULTS FOR STEADY STATE THERMAL

ANALYSIS
STAINLESS STEEL 410
Steady-state thermal analyses to calculate the
thermal response to heat loads depending on the
prescribed temperatures or applied convection
conditions or both. Steady-state thermal analyses
assume a steady-state for all thermal loads and
boundary conditions. This form of analysis does not
evaluate changes over time, where heat storage
effects varying over a period of time can be ignored.

Heat transfer is the physical act of thermal energy

being exchanged between two systems by dissipating
heat. Temperature and the flow of heat are the basic
principles of heat transfer. The amount of thermal
energy available is determined by the temperature,
and the heat flow represents movement of thermal
energy.

Temperature variation and heat flux throughout the

MAXIMUM TEMPERATURE
geometry of the rotor are calculated and analysed
here GREY CAST IRON
MAXIMUM HEAT FLUX

GREY CAST IRON

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SLOT 1

MAXIMUM HEAT FLUX: 5.4115𝑒 5 w/𝑚2

MINIMUM HEAT FLUX: 881.46 w/𝑚2

SLOT 2

MAXIMUM HEAT FLUX: 5.1958𝑒 5 w/𝑚2

MINIMUM HEAT FLUX: 329.03 w/𝑚2

STAINLESS STEEL 410

SLOT 1
STAINLESS STEEL 410
MAXIMUM HEAT FLUX: 4.2936𝑒 5 w/𝑚2

MINIMUM HEAT FLUX: 351.95 w/𝑚2

SLOT 2

MAXIMUM HEAT FLUX: 4.407𝑒 5 w/𝑚2

MINIMUM HEAT FLUX: 323.63 w/𝑚2

MAXIMUM TEMPERATURE

RESULTS

GREY CAST IRON

SLOT 1

MAXIMUM TEMPERATURE: 232.95 ℃

MAXIMUM HEAT FLUX
MINIMUM TEMPERATURE: 60.39 ℃
RESULTS
SLOT 2
GREY CAST IRON
MAXIMUM TEMPERATURE: 252.95 ℃

MINIMUM TEMPERATURE: 69.07 ℃

STAINLESS STEEL 410

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SLOT 1 iii) Hence SS410 of diameter 170mm with

slot1 is the best choose. Further it can be
MAXIMUM TEMPERATURE: 267.19 ℃
optimized more by increasing width of the slot
MINIMUM TEMPERATURE: 36.806 ℃ so as to reduce maximum temperature without
compromising with stress control since it has
SLOT 2 more yield strength.
MAXIMUM TEMPERATURE: 284.28 ℃ REFERENCE
MINIMUM TEMPERATURE: 40.15 ℃
Journals:
INFERENCE AND CONCLUSION 1. Akshaykumar Bote, Sumeet Satope, and
1. Comparing material, it has been found that Swapneel D. Rawool, (2017), ‘Thermal Analysis
maximum stress produced is equal to each other of Disc Brake’, IJIRST –International Journal for
and below its yield strength. But for SS410 Innovative Research in Science &
maximum stress very much lower than its yield Technology,Volume 3 , Issue 12 , May 2017, ISSN
strength which results less deformation than (online): 2349-6010
gray cast iron and it can further increase its 2. Madhu Maheswara Reddy.Y , and Usha Sri.P
surface area to increase heat dissipation. ,(2014), ‘Heat Transfer Analysis of Automotive
2. Maximum temperature of SS410 is little more Disc Brake’, IJARSE, Vol. No.3, Issue No.9,
than gray cast iron. And SS410 temperature September 2014
range is lesser than grey cast iron, which shows 3. Aditya Patankar , Sameer Ingale ,Sanket
poor conduction. Kothawade, and Rohit Kulkarni. (2016),
‘Determination Of Heat Transfer Coefficient Of
3. Comparing pattern design slot 2 has less stress
Brake Rotor Disc Using CFD Simulation’,
than slot 1 as well as its deformation
International Journal of Mechanical Engineering
4. So, it has been concluded and Technology (IJMET), Volume 7, Issue 3, May–
June 2016, pp.276–284
I) If corrosion resistance is the priority,
SS410 of diameter 170 mm with slot 1 is best 4 .Sanket Darekar, Ajinkya Dhage, Nimish
selection though it has high stress which is far Ghumatkar, Shivam Gosavi, Prof. S.M. Alage, ‘
less than yield strength, it has less possibility of Design and Analysis of Automotive Disc Brake
cracking and wear off at bolted place. And also, using FEM’, International Research Journal of
the cost of machining is also comparatively less. Engineering and Technology (IRJET), Volume:
07, Issue: 01, Jan 2020
ii) If reducing brake fade is priority, gray
cast iron of diameter 170 mm with slot 2 is best 5. B.Subbarayudu , Ginjala Kishore , ‘Design and
selection. Analysis of Ventilated Disc Brake’, IOSR Journal
of Mechanical and Civil Engineering (IOSR-
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JMCE) ,e-ISSN: 2278-1684,p-ISSN: 2320-334X,

Volume 15, Issue 5 Ver. I (Sep. - Oct. 2018), PP
46-59

6. Alok Kumar, Shatakshi Dwivedi, Tuhin

Srivastava, ‘Design and Analysis of Disc Brake
with different drill pattern, drill size, drill angle
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Engineering Research, ISSN 0973-4562 Volume
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