Airo International Research Journal August, 2018 Volume XV ... · The analysis performed in ANSYS...

Airo International Research Journal August, 2018

Volume XV, ISSN: 2320-3714

Impact Factor 0.75 to 3.19

1




ANALYSIS AND PERFORMANCE IMPROVEMENT OF A DISC

BRAKE REPLACING TRADITIONAL MATERIAL GREY CAST IRON

IN ANSYS

Haider Ali Naqvi1, Josy George

2, Mukesh Sahu

3

Assistant Professor, Department of Mechanical Engineering, Lakshmi Narain College of

Technology, Bhopal

Declaration of Author: I hereby declare that the content of this research paper has been truly made by me including the title of the research paper/research article, and no serial sequence of any sentence has been copied through internet or any other source except references or some unavoidable essential or technical terms. In case of finding any patent or copy right content of any source or other author in my paper/article, I sha ll always be responsible for further clarification or any legal issues. For sole right content of different author or different source, which was unintentionally or intentionally used in this research paper shall immediately be removed from this journal and I shall be accountable for any further legal issues, and there will be no responsibility of Journal in any matter. If anyone has some issue related to the content of this research paper’s copied or plagiarism content he/she may cont act on my above mentioned email ID.

ABSTRACT

In today’s developing automobile sector, there is drastic change in the technology from

transmission system to braking system. The braking system is considered as one of the most

important system from performance as well as safety point of view. When the brakes are

applied to the moving vehicle, all the kinetic energy of the vehicle gets converted into

equivalent amount of heat generation.

The aim of this research work is to choose best material which is light in weight and fulfill all

design requirements. The model of disc is created in CATIA V5 while the analysis is

conducted in ANSYS 19.0. The analysis performed in ANSYS is steady static structural.

Keywords –Static structural analysis, Finite Element Method, Disc Brake, ANSYS etc

I. INTRODUCTION

A brake is a device by means of which

artificial frictional resistance is applied to

moving machine member, in order to stop

the motion of a machine. In the process of

performing this function, the brakes absorb

either kinetic energy of the moving

member or the potential energy given up

by objects being lowered by hoists,

elevators etc. The energy absorbed by

brakes is dissipated in the form of heat.

This heat is dissipated in the surrounding

atmosphere to stop the vehicle, so the

brake system should have following

requirements:

The brakes must be strong

enough to stop the vehicle with

in a minimum distance in an

emergency.

The driver must have proper

control over the vehicle during

braking and vehicle must not

skid.

The brakes must have well anti

fade characteristics i.e. their

effectiveness should not

decrease with constant

prolonged application.

The brakes should have well

anti wear properties.




When hydraulic pressure is applied to the

caliper piston, the pressure tends to exert a

force on the caliper which results in

squeezing the disc between two friction

surfaces of the disc. Since disc brakes do

not use friction between the lining and

rotor to increase braking power as drum

brakes do, they are less likely to cause a

pull. As most of the portion of the disc

brake is exposed to the surrounding, there

is best heat dissipation rate which gives

faster cooling of the disc brake disc. This

phenomenon plays an important role in

minimizing the brake fade. It also allows

for self-cleaning as dust and water is

thrown off, reducing friction difference.

A. PROBLEM OCCURRED IN DISC

BRAKE

Discs are made up mainly gray cast iron,

so discs are damaged in one of three ways:

scarring, cracking, warping or excessive

rusting. Service shops will sometimes

respond to any disc problem by changing

out the discs entirely. This is done mainly

where the cost of a new disc may actually

be lower than the cost of workers to

resurface the original disc. Mechanically

this is unnecessary unless the discs have

reached manufacturer's minimum

recommended thickness, which would

make it unsafe to use them, or vane

rusting. severe (ventilated discs only).

Most leading vehicle manufacturers

recommend brake disc skimming (US:

turning) as a solution for lateral run-out,

vibration issues and brake noises.

The machining process is performed in a

brake lathe, which removes a very thin

layer off the disc surface to clean off

minor damage and restore uniform

thickness. Machining the disc as necessary

will maximize the mileage out of the

current discs on the vehicle. Braking

systems rely on friction to bring the

vehicle to a halt – hydraulic pressure

pushes brake pads against a cast iron disc

or brake shoes against the inside of a cast

iron drum. When a vehicle is decelerated,

load is transferred to the front wheels –

this means that the front brakes do most of

the work in stopping the vehicle. Scarring

can occur if brake pads are not changed

promptly when they reach the end of their

service life and are considered worn out.

II. LITERATURE REVIEW

Swapnil.D.Kulkarni (2017)research in

disc brake is the recent trend in automobile

vehicles which dissipates the heat faster

than the conventional drum brakes. but if

hard braking is done, there is induction of

thermal stresses in the brake disc which

leads to generation of excessive

temperature .if this heat is not dissipated

properly, then distortion will be get

produced in the disc which leads to

thermal cracking of the disc leading to disc

failure. The brake disc has an inherent

ability that there is no change of co-

efficient of friction on the disc so there is

no problem of brake fading phenomenon.

The main advantage of disc brake is that

only a small portion of the disc is in

contact with the friction material i.e. the

caliper. Hence there is large surface area

of the disc which can dissipate the heat to

the atmosphere. Specifically the heat

dissipated to the atmosphere is the forced

convection mode. The aim of this research

work is to choose best profile and best

material which can dissipate maximum

amount of heat to the surrounding.




Prof. Mit Patel (2016) study in

optimization of technical aspects in

automobile is very important and

necessary as there are large numbers of

vehicles running on road today, so that

part or product will be durable, safe and

affordable to the users. The brakes are

very important aspects of a vehicle as it

fulfils all the stopping functions and

requirements. As brakes have to undergo

through continuous use, many issues

surround their heating characteristics when

it comes to their development, including

contact region properties, material choice,

development of hot spots, associated

physical geometry, and deformations. The

main purpose of this study is to analysis

the thermo-mechanical behaviour of the

brake disc during the braking phase. The

coupled thermal-structural analysis is used

to determine the deformation and the Von

Mises stress established in the disc to

enhance performance of the rotor disc. A

comparison between analytical and results

obtained from FEA is done and all the

values obtained from the analysis are less

than their allowable values. Hence best

suitable design, will be suggested based on

the performance, strength and rigidity

criteria.

C. Radhakrishnan P (2015) said that disc

brake is a device by means of which

artificial frictional resistance is applied to

rotating disc, in order to stop the motion of

vehicle. During the braking phase, the

frictional heat generated at the interface of

the disc and pads can lead to high

temperatures. The frictional heat generated

on the rotor surface can influence

excessive temperature rise which, in turn,

leads to undesirable effects such as

thermal elastic instability (TEI), premature

wear, brake fluid vaporization (BFV) and

thermally excited vibrations (TEV).This

causes will be reduced by better thermal

stability materials. In this project we

analyze the thermal behavior of the

ventilatedbrake disc with Titanium alloy

(Ti 550) and conventional grey cast iron

material in finite element software ANSYS

WORKBENCH 14.0. Modeling of the disc

brake rotor is done using SOLIDWORKS

2013.Finally a comparison is made

between conventional grey cast iron and Ti

550 materials and the best material for

making disc brake have been suggested

based on the magnitude of Von misses

stresses, temperature distribution and

deformation from the thermal analysis

result.

Swapnil R. Abhang (2014)said that each

single system has been studied and

developed in order to meet safety

requirement. Instead of having air bag,

good suspension systems, good handling

and safe cornering, there is one most

critical system in the vehicle which is

brake systems. Without brake system in

the vehicle will put a passenger in unsafe

position. Therefore, it is must for all

vehicles to have proper brake system. In

this paper carbon ceramic matrix disc

brake material use for calculating normal

force, shear force and piston force and also

calculating the braking distance of disc

brake. The standard disc brake two

wheelers model using in ANSYS and done

the Thermal analysis and Modal analysis

also calculate the deflection and Heat flux,

Temperature of disc brake model. This is

important to understand action force and

friction force on the disc brake new




material, how disc brake works more

efficiently, which can help to reduce the

accident that may happen in each day.

N. Balasubramanyam (2014)study in

transient analysis for the thermo elastic

contact problem of the disk brakes with

heat generation is performed using the

finite element analysis. To analyze the

thermo elastic phenomenon occurring in

the disk brakes, the occupied heat

conduction and elastic equations are

solved with contact problems. The

numerical simulation for the thermo elastic

behavior of disk brake is obtained in the

repeated brake condition. The

computational results are presented for the

distribution of heat flux and temperature

on each friction surface between the

contacting bodies. Also, thermo elastic

instability (TIE) phenomenon (the unstable

growth of contact pressure and

temperature) is investigated in the present

study, and the influence of the material

properties on the thermo elastic behaviors

(the maximum temperature on the friction

surfaces) is investigated to facilitate the

conceptual design of the disk brake

system. Based on these numerical results,

the thermo elastic behaviors of the carbon-

carbon composites with excellent

mechanical properties are also discussed.

III. OBJECTIVE

The brakes are one of the most important

control components of vehicle. They are

required to stop the vehicle within the

smallest possible distance and this is done

by converting the kinetic energy of the

vehicle into the heat energy which is

dissipated into the atmosphere.

The main objective of this study to

introduce new material on the disk brake

by replacing traditional material (Gray cast

iron) and increase the overall performance

of the disk brake.

IV. METHODOLOGY

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.




6

Fig. 1 Working of Disc Break

When the brake lever or pedal is released

the piston ring pushes the caliper piston

back to cylinder bore of caliper till both,

caliper piston and piston ring come into

their original shape. At this time retraction

spring pushes the brake pads to their

original position. The return spring in

master cylinder assembly pushes the

master cylinder piston back into its

original position and allows the fluid to

flow back to reservoir via hosepipe and

master cylinder bore.

A. DESIGN CALCULATION

1) The brake pedal:

Brake pedal is an mechanical component

used in the brake system of motor cycles

and cars where the driver foot is used for

applying the pressure to stop the vehicle in

the running condition. In this system the

increase in force is always equal to the

multiplication of lever ratio used in the

levels of the brake pad assembly.

Fbrake pedal = Fd × [L1 / L2]

Where,

Fbp = the force output of the brake

pedal assembly

Fd = the force applied to the pedal

pad by the driver = 370 N

L1 = the distance from the brake

pedal arm pivot to the output rod clevis

attachment

L2 =the distance from the brake

pedal arm pivot to the brake pedal pad

(L1/L2 = 4)

The incompressible liquid is assuming in

master cylinder of disk brake and its fixed

hydraulic vessels, the pressure calculation

of master cylinder will be denoted in

formula

𝑃𝑚𝑐 =𝐹𝑏𝑝𝐴𝑚𝑐

Where




Pmc= the hydraulic pressure

generated by the master cylinder.

Amc= the effective area of the

master cylinder hydraulic piston =

0.000285 m2.

Brake fluid, brake pipes and hoses:

Assuming no losses along the length of the

brake lines, the pressure transmitted to the

calipers will be equal to:

Pcal = Pmc

Where,

Pcal= the hydraulic pressure

transmitted to the caliper.

The rotor: This torque is related to

the brake pad frictional forceas follows:

Tr= Ffriction× Reff

Where,

Tr= the torque generated by the

rotor.

Reff= the effective radius (effective

moment arm) of the rotor (measured from

the rotor center of rotation to the center of

pressure of the caliper pistons).

This torque generated by the rotor

will be equal to the torque required to stop

the vehicle. In this report, they follow

Mass of the vehicle = 300

kg.

Maximum velocity of the

vehicle = 80 km/hr or 22.22

m/s.

Stopping Distance = 11.69

m.

Tire Size = 23 in diameter

that is 584.2 mm with 7

mm thickness

Disc flange or thickness =

16 mm.

50-50 wheel bias that is

equal braking force is

generated in all the 4

wheels of the vehicle.

Total force generated during

braking to stop the car,

F = m×a, a = deceleration during

braking = v2/2s = 22.222/2 x 11.69= 21.12

m/s2

F= 300 x 21.12

F= 6336 N.

Torque required stopping the

vehicle,

Tr= F/4 ×Rw

Tr= 6336/4 x 0.2921

Tr= 462.54 N-m.

As mentioned in above formulae,

Fbp= Fd× (L1/L2)

Fbp= 370 x 4

Fbp= 1480 N.

P = Fbp/Amc




Pmc= 1480/0.000285

Pmc= 5192982.456 Pa

Pmc= Pcal= 5192982.456 Pa

Fcal= Pcal ×Acal

Fcal= 5192982.456 x 0.0007068

Fcal= 3670.4 N.

Clamping Force = 2Fcal.

Fclamp= 7340.8 N.

Ffriction= Frictional force

generated on the rotor during

brakingprocess,

Ffriction= 7340.8 × 0.4

Ffriction= 2936.32 N

Torque generated by the rotor

during braking = Ffriction×Reff= 462.54

Therefore, the effective rotor radius

Reff= 0.1575 m.

Thus, the Effective Rotor Radius is

0.1575 meters that is 6.2 inches or 157.5

mm. And thus, the effective diameter is

315 mm.

Based on this effective diameter,

the outer diameter of the disc isdecided to

be 381 mm and the inner diameter to be

125 mm.

Kinetic Energy developed during

braking,

KE = ½ mv2

KE = ½ x 300 x (22.22)2

KE = 74059.26 J

B. PROCEDURE FOR ANSYS

ANALYSIS

Static analysis is used to determine the

displacements stresses, stains and forces in

structures or components due to loads that

do not induce significant inertia and

damping effects. Steady loading in

response conditions are assumed. The

kinds of loading that can be applied in a

static analysis include externally applied

forces and pressures, steady state inertial

forces such as gravity or rotational

velocity imposed (non-zero)

displacements, temperatures (for thermal

strain). A static analysis can be either

linear or nonlinear. In our present work we

consider linear static analysis. The

procedure for static analysis consists of

these main steps

Building the model

Obtaining the solution

Reviewing the results.

C. MATERIAL PROPERTIES

There are two material are used in

analysis one is gray cast iron and second is

aluminium 2014-T6, the general property

of material are as follows:

Table 1: Material Properties of gray cast iron and aluminium alloy.




Gray cast iron Aluminium

2014-T6

Density (kg/m3) 7200 2400

Young’s Modulus (GPa) 125 4270

0

Poisson’s ratio 0.25 0.33

D. STEPS OF ANSYS ANALYSIS

The different analysis steps involved in

ANSYS are mentioned below.

1) Pre-process

The model setup is basically done in pre-

processor. The different steps in pre-

processing are

2) Building the model

The CATIA provides the following

approaches for model generation: Creating

a solid model within CATIA. Every design

starts with the conventional calculations by

applying various fundamentals of design.

The basic model of disk brake is creating

in following step.

Fig. 2: Final base model of Disk brake in Catia




Fig. 3 Sketch of Basic Disk Brake model

E. Meshing

ANSYS Meshing includes intelligent,

general-purpose, automated high-

performance type of product. It delivers

the most suitable work for exact, proficient

Multi physics arrangements. A work

appropriate for a particular investigation

can be created with a solitary mouse click

for all parts in a model. For the master

client who needs to tweak on it give full

controls over the alternatives used to

create the work are accessible. The energy

of parallel preparing is consequently used

to decrease the time you have to wait for

mesh generation.

Creating a mesh in the imported geometry

is an important step in ANSYS analysis as

the size of the finite element is decided by

the mesh properties. Finer the mesh is,

more accurate are the results.

After the given meshing in ANSYS the

number of element is 13888 and number of

Nodes is27527

.




Fig 4: Meshing of base model

Table 2: Nodes & Element

Number of Nodes 1574

5

Number of

Elements

7753

F. BOUNDARAY CONDITION

The next step in the static structural

ANSYS analysis is to apply the boundary

conditions. All six hole are fixed in

applying fixed support and the after

applying a force, this force are applying in

disk brake in to opposite surfaces of disk

brake. The total applying force is 2936.32

Newton is apply in top and bottom of disk

brake. The above analysis is study in total

deformation equivalent stress and strain

analysis. Giving 27.63 rpm rotational

velocity for disk brake by clockwise

direction run calculation and monitoring

the solution. Since Also since the disc has

to be fixed at its centers, fixed supports are

given to the hub bolts and the inner portion

of the entire inner circle. Thus, overall

there are 4 initial boundary conditions

given to the disc rotors model or geometry

before proceeding to the solution.

Fig. 5 Boundary condition




V. RESULT

A. ANSYS analysis of Gray cast iron disk brake

Fig. 6: Total deformation of Gray cast iron disk brake

Fig. 7 Equivalent stress of Gray cast iron disk brake




Fig. 8 Strain of Gray cast iron disk brake

B. ANSYS analysis of Aluminium alloy disk brake

Fig. 9: Total deformation of Aluminium alloy disk brake




Fig. 10 Equivalent stress of Aluminium alloy disk brake

Fig. 11 Strain of Aluminium alloy disk brake

C. Comparison deformation of disk brake

The maximum deformation of Gray cast iron disk brake model is 1.2437e-6 m and

total deformation of aluminium alloy model is 2.1379e-9m

Table 3 Result of deformation

Disk brake model Deformation

(m)

Base model 1.2437e-6

Aluminium model 2.1379e-9




Graph 1 Comparison deformation

D. Comparison Equivalent stress of disk brake

The maximum equivalent stress of Gray cast iron disk brake model is 4.2158e6 Pa

and equivalent stress of Aluminium alloy model is 4.2187e6 Pa.

Table 4: Result of Equivalent stress

Disk brake model Equivalent stress

(Pa)

Gray cast iron 4.2158e6

Aluminium alloy 4.2187e6

Base Model Aluminium Model

Deformation (m) 1.24E-06 2.14E-09

0.00E+00

2.00E-07

4.00E-07

6.00E-07

8.00E-07

1.00E-06

1.20E-06

1.40E-06D

efo

rmat

ion

Deformation (m)




Graph 2 Comparison Equivalent stresses

E. Comparison Strain of disk brake

The maximum Strain of disk brake base model is 3.778e-5 and Strain of aluminium model is

5.8354e-8

Table 5 Result of Strain

Disk brake model Strain (m/m)

Gray cast iron 3.778e-5

Aluminium alloy 5.8354e-

8

Gray cast iron Aluminium alloy

Equivalent stress (Pa) 4.22E+06 4.22E+06

0.00E+00

1.00E+06

2.00E+06

3.00E+06

4.00E+06

5.00E+06Eq

uiv

ale

nt s

tre

ss

Equivalent stress (Pa)




Graph 3 Comparison strain

F. Comparison Weight of disk brake

The Weight of Graycas iron disk brake model is 5761.3 Kg and weight of Aluminium alloy

model is 2.2405Kg.

Table 6: Result of Weight

Disk brake

model

Weight

(gm)

Gray cast iron 5.7613

Aluminium alloy 2.2405


Strain (m/m) 3.78E-05 5.84E-08

0.00E+00

5.00E-06

1.00E-05

1.50E-05

2.00E-05

2.50E-05

3.00E-05

3.50E-05

4.00E-05

Stra

inStrain (m/m)




Graph 4 Comparison Weight

VI. CONCLUSION

Structural analysis is done on disc rotor for

two materials Gray cast iron and

Aluminum alloy. A present used material

for disc brake is Gray cast iron. We are

replacing the material with Aluminum

alloy, since its density is less than that of

Gray cast iron thereby reducing the weight

of disc brake. By observing the stress

values obtained in structural analysis, they

are less than the yield stress value of

Aluminum alloy, so using Aluminum alloy

for disc brake is safe. So using Aluminum

alloy is better. Reducing weight of disc

rotor, Braking system becomes less bulky

and compact. Moreover, with increased

weight braking force also increases, hence

weight reduction can result is effective

performance of disc brake.

Failure criteria of disc brake rotor is

equivalent stress, for both Aluminum as

well as Gray cast iron equivalent stress is

less than ultimate strength hence both

design are safe. But weight of Gray cast

iron is more than that of Aluminum, hence

to reduce weight of disc brake rotor it

should be made of Aluminum alloy.

VII. REFERENCE

[1] Swapnil.D.Kulkarni, J.J.Salunke

(2017) “THERMAL ANALYSIS

OF BRAKE DISC” IJRET:

International Journal of Research

in Engineering and Technology

eISSN: 2319-1163 | pISSN: 2321-

7308Volume: 06 Issue: 02

[2] Prof. Mit Patel, MansiRaval, Jenish

Patel (2016) “Design of Disc

Brake’s Rotor” International

Journal of Engineering

Development and ResearchVolume

4, Issue 4 | ISSN: 2321-9939

[3] C.RadhakrishnanP,

P,Yokeswaran.KP, P,

Vengadeshprasadh.MP,


Weight (Kg) 5.7613 2.2405

0

1

2

3

4

5

6

7W

eigh

tWeight (Kg)




P,Vishnuhasan.AP, P, Vimalraj.TP,

P, Velusamy.MP (2015) “DESIGN

AND ANALYSIS OF DISC

BRAKE WITH TITANIUM

ALLOY” IJISET - International

Journal of Innovative Science,

Engineering & Technology, Vol. 2

Issue 5

[4] Swapnil R. Abhang#1,

D.P.Bhaskar (2014) “Design and

Analysis of Disc Brake”

International Journal of

Engineering Trends and

Technology (IJETT) – Volume 8

[5] N. Balasubramanyam, Prof. Smt.

G. Prasanthi (2014) “Design and

Analysis of Disc Brake Rotor for a

TwoWheeler” International Journal

of Mechanical and Industrial

Technology (IJMIT)Vol. 1, Issue 1,

pp: (7-12)

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