Design and Finite Element Analysis of Disc Brake with different ... · with different materials for passenger car Snehita Kilari1, Tara Sasanka C2, K.G.S.V.Manikanta3 1,2Assistant

© 2018 IJRTI | Volume 3, Issue 8 | ISSN: 2456-3315

IJRTI1808018 International Journal for Research Trends and Innovation (www.ijrti.org) 114

Design and Finite Element Analysis of Disc Brake

with different materials for passenger car

Snehita Kilari1, Tara Sasanka C2, K.G.S.V.Manikanta3

1,2Assistant professor, 3UG Student,

Department of Mechanical Engineering,

RVR&JC College of Engineering, Chowdavaram, Guntur, Andhra Pradesh, India.

Abstract: Disc brake is a mechanical device which is a essential component of the vehicle and is utilized widely for the

protection of the passengers therefore a conventional breaking setup is necessary for all the vehicles. Disc brake fulfils

different functions and requirements which include slowing or stopping the revolving wheel, preventing its motion. The

major objective here is to find out the effect of the load on the component during the period of braking therefore an attempt

is made to design a solid model of disc brake to analyse it, so as to improve the performance and to observe the deformations

and stresses. Structural analysis is conducted on three materials which include Grey cast iron, aluminium alloy and

structural steel. The present work lime lights the aspect of typical disc brake system for automobiles which is modelled using

CATIA for the above mentioned three materials and the analysis is completed in ANSYS. When compared, the results of

analytical with that of finite element, it is observed that the values obtained from the FE analysis are less than their

permissible values. Henceforth the best suitable design for the application can be determined from their strength,

performance and rigidity criterion.

Keywords: ANSYS, CATIA, Aluminium, Cast Iron, Steel, Disc Brake, Finite Element Method, Structural Analysis.

_____________________________________________________________________________________

I. INTRODUCTION

The launch of the tradition of disc-style brakes has its initiation in England during 1890's. In 1902, the Lanchester Motor

Company designed brakes that appeared and functioned in an identical manner to a modern disc-brake system[1]. Frederick William

Lanchester was the person to be patented the earliest caliper style vehicle disc brake in his Birmingham factory. Disc brakes were

trendy on sports cars when they were initially launched, as sports cars require more effective brake performance thus they were

initially introduced and tested in them. The competition for exceptionally operating vehicle in the present automotive world is

increasing.

Discs which are common in light weight vehicles are being used in passenger vehicles too. The mass and power of the

vehicle decides the necessity of ventilated holes on the disc. When weight and power of the vehicle increases the heat production

also increases as it determines the number of holes thereby modifying their shape and size. Frequent application of brakes impact

the heating characteristics in the case of development, material preference, contact region properties, physical geometry and

deformations.

The brake discs are commonly made up of materials like Cast iron, Aluminium, Structural steels or composites like

reinforced carbon-carbon composites or ceramic matrix composites etc,. Brakes convert kinetic energy to thermal energy, this

phenomenon is known as brake fade. Too hot brakes are not efficient. Disc brakes are less exposed to the brake fade. Even when

the brake components are overheated quick recovery takes place since they are provided with vent holes and are readily cooled.

II. FUNCTIONING OF DISC BRAKE

The major components of a disk brake are as shown in the below Fig.1.

Brake pads, couple of brake pads are forced adjacent to the disc which causes friction. It allows the motion of the disc to slow

or stop.

Caliper, it consists of the brake pads and pistons, is attached to the wheel hub and fixed housing.

Rotor, rotating part in the braking system which spins the wheel.

Hub, rotates with the axle, placed at the centre of the wheel.

Vents, helps in reducing the temperature caused by frequent application of brakes[2].

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Figure.1: Components of disc brake

Working Principle

Braking can be done mechanically, pneumatically, hydraulically or electromagnetically by forcing a pair of brake pads

which are forced adjacent to both sides of the disc which causes friction. The Pascal’s Law/Principle of transmission of fluid

pressure is fundamental for the functioning of a disk brake. The functioning of a hydraulic braking arrangement is shown in the

below Fig.2. When brake pedal is pressed, the push rod that is linked to pedal and master cylinder accelerates the master cylinder

piston. Thus the master cylinder piston moves back and forth in order to push the return spring which is placed inside the bore of

master cylinder, creates pressure inside reservoir tank. Brake fluid starts flowing from reservoir tank to brake hosepipes through a

primary seal. A secondary seal is made available to make sure that the brake fluid does not go in any other way. Then the fluid

enters into cylinder bore of caliper assembly via brake hose pipes and pushes the caliper pistons, followed by the rolling motion of

piston ring with piston. The caliper then drives the brake pad. Brake pads stick with brake disc which generates friction, allowing

the motion of the disc to slow or stop[3].

Figure.2:Working of hydraulic brake system

Brake Power Calculations

Braking power calculation is essential since braking performance of vehicles is a significant issue in order to prevent

accidents. The Mass of the vehicle is 2000 kg, initially travelling at 80kmph (22.22m/s)which comes to rest after the brake

application. brake rotor diameter of designed brake is 0.258m, coefficient of friction is μ=0.6 ,Axle weight distribution on each

side 30%,(γ)=0.3, Percentage of kinetic energy absorbed by the disc is 85%( k)=0.85[1].

Energy generated is K.E = k 1

2 γ

m (u−v)2

2

= 0.85 1

2 (0.3)

2000 (22.22−0)2

2

= 62950.37 J

Vehicle should be stopped at a distance of 41.94 m

Within a time of t=5.8 sec

Braking power is P= K.E

𝑡 =

62950.37 J

5.8 sec =10853.5 W

III. DESIGN & ANALYSIS

Design Methodology

CATIA is a multi-platform mechanical design suite. It is a characteristic aided supported, parametric solid modelling

design tool. Conceptualization, design, engineering, manufacturing and PLM are multiple phases supported by CATIA. It is easy

to transform 2D sketches into 3D parts in CATIA as it has user-friendly graphical interface. By means of using automatic or user

described relations to confine design objective complete 3-D replica are generated with or without constraints. The disc brake

presented in the paper is designed using the version P3 V5 R11 which is as shown in the Fig.3. To perform operations like add,




remove, rotate, sweep and cut the material while modelling, the different features used are Pad, Pocket, Revolve, Rib, Slot, Loft etc

for this design[3,8]. The designed Disc Brake can be imported to "IGES" format and later it is exported to the ANSYS for analysis.

Figure.3: Solid model of disc brake in CATIA

FEA & Static Structural Analysis with ANSYS

With its diversity and flexibility as an analysis tool the finite element method is the best method to arrive at a solution/s to

diverse engineering problems[4]. Though it is not possible to provide mathematical solutions to various engineering problems but

to solve problems related to complex material properties and boundary conditions FEA is accepted to be the most viable and potent

tool in industries. In finite element analysis, Structural analysis is universally preferred to analyse civil engineering structures such

as buildings and bridges but also mechanical components such as machine tools, parts, aerospace/naval engineering structures

including aircraft bodies, ship hulls and machine housings as well as etc. Static structural analysis is carried out to observe stresses,

strains, displacements and forces caused by different loads based on the assumptions of steady loading and response conditions[5].

The following table1 shows three different materials with the properties required to conduct analysis in workbench[7].

C. Types Of Structural Analysis

Essentially seven varieties of structural analysis are discussed below[5]:

a) Static Analysis, Displacements, stresses, etc. can be determined under static loading conditions.

b) Modal Analysis, Natural frequencies and mode shapes of a structure can be determined.

c) Harmonic Analysis, response of a structure to harmonically time-varying loads can be observed.

d) Transient Dynamic Analysis, response of a structure to arbitrarily time-varying loads can be observed.

e) Spectrum Analysis, an extension to modal analysis, stresses and strains due to a response spectrum can be calculated.

f) Buckling Analysis, buckling loads, buckling mode shapes can be determined.

g) Fatigue Analysis, response of a design subjected to a specified environment of restraints and loads can be observed.

TABLE 1: PROPERTIES OF MATERIALS

Properties Cast Iron Al6082 Structural Steel

Density ρ(kg/m3) 7300 2700 8600

Young's Modulus E (GPa) 136 71 220

Poisson's Ratio ν 0.26 0.34 0.29

Thermal Conductivity (W/m K) 48 180 37

Specific Heat c (J/Kg 0C) 475 940 435

Coefficient of Expansion α (/0K) 11.5 X 10-6 24 X 10-6 12.6 X 10-6

Step Wise Analysis In ANSYS

General steps involved in the ANSYS are as following[6]:

a) Preliminary Decisions

Analysis type

Model

Element type

b) Pre processing

Material

Import the model

Mesh the model

c) Solution

Apply loads

Solve

d) Post processing

Review results




Check the solution

Mesh Generation

The purpose of meshing is to offer robust and simplified mesh generation process[9]. The solid model of disc brake which

is imported to workbench in IGES format should be divided into finite elements. Elements used for meshing are tetrahedral three-

dimensional elements. A finite element mesh model generated in workbench 14.5 is shown in Fig.4. Boundary conditions are then

applied to these elements and nodes.

Figure.4:Generated mesh using ANSYS workbench

IV. RESULTS

The behaviour of present disc brake models can be evaluated based on their deformations (shown in table 2), stresses

under the operating condition of the constant hydraulic pressure. The following Fig. 5,6,7,8,9,10,11,12 shows principal stresses,

von-mises stresses for the three materials cast iron, aluminium alloy, structural steel. Regarding the outcomes they are acceptably

in agreement with those generally found in the literature survey.

As Elastic modulus is high for Structural steel, its stress ranges are also high when compared with aluminium alloy.

Deformation is also less for aluminium alloy. Also the Von-Mises stress are less when compared with other materials. And for Cast

iron the stress range is equivalent to structural steel. Since cast iron disc brakes experience corrosion when contacted with moisture,

it is not preferred.

Figure. 5:Maximum principal stresses of cast iron Figure. 6:Minimum principal stresses of cast iron




Figure. 7:Von-Mises stresses of cast iron Figure. 8:Maximum principal stresses of Aluminium alloy

Figure. 9:Minimum principal stresses of Aluminium alloy Figure. 10:Vonmises stresses of Aluminium alloy

Figure. 11:Maximum principal stresses of structural steel Figure. 12:Minimum principal stresses of structural steel

Figure. 13:Von-Mises stresses of structural steel

TABLE2 : DEFORMATION OF THREE MATERIALS

Cast iron 0.4317 mm

Aluminium alloy 0.1182mm

Structural steel 0.2573mm




V. CONCLUSION

The inside region of the disc where shaft is to be located will be effected more compared to any other part of the disc. On

evaluating the deformations and stresses attained as a result of given pressure the disc made of aluminium alloy considered here

can withstand the applied pressure. Also aluminium alloys are efficient for use in automotive components owing to their low

weight. The further experiment can be conducted with addition of pressure and can be analysed. Design is safe on the basis of

strength and rigidity except that the stresses found in the results are not adequate with the practical scenarios. It would be interesting

to resolve the problem in thermo mechanical disc brakes with an experimental study to confirm the numerical results,

recommendations for the extension of future work related to disc brake is as follows: Tribological study of contact disc- pads,

experimental study to test the precision of numerical model developed. To get better performance material design modifications

may be made on structural design. Thermal analysis can also be suggested for analysis in future to test brake behaviour when

subjected to temperature.

REFERENCES

[1] Manjunath T V, Dr Suresh P M, "Structural and Thermal Analysis of Rotor Disc of Disc Brake", International Journal of

Innovative Research in Science, Engineering and Technology, Vol. 2, Issue 12, pp. 7741-7742, December 2013.

[2] Er. N. B. Shinde1, Prof. B.R. Borkar2, "C.A.D. & F.E.M. ANALYSIS OF DISC BRAKE SYSTEM", International Journal

Of Engineering And Computer Science, Volume 4, Issue 3, pp.10697-10698, March 2015.

[3] Prof. Mit Patel, Mansi Raval, Jenish Patel, "Design of Disc Brake’s Rotor", International Journal of Engineering

Development and Research, Volume 4, Issue 4, pp.919-920, 2016.

[4] K.Sowjanya, S.Suresh, "Structural Analysis of Disc Brake Rotor", International Journal of Computer Trends and

Technology, volume 4, Issue 7, pp.2296-2297, July 2013.

[5] “The trusted ANSYS mechanical suite rapidly complex structural problems with ease”, Wikipedia.

[6] Praveena S, Lava Kumar M, Kesavulu A, "Modeling and Thermal Analysis of Disc Brake", International Journal of

Engineering Research and Applications, Vol. 4, Issue 10 (Part-3), pp. 103-104, October 2014.

[7] Ashby M F. Materials selection in mechanical design. 3rd ed. UK: Butterworth Heinemann; 2005.

[8] Sunkara Sreedhar, Parosh.G, "DESIGN AND STRUCTURAL ANALYSIS OF DISC BRAKE BY USING CATIA AND

ANSYS-WORKBENCH", International Research Journal of Engineering and Technology, Volume 04, Issue 09, pp.70-

72, 2017.

[9] V.M.M.Thilak, R.Krishnaraj, Dr.M.Sakthivel, K.Kanthavel, Deepan Marudachalam M.G, R.Palani, "Transient Thermal

and Structural Analysis of the Rotor Disc of Disc Brake", International Journal of Scientific & Engineering Research,

Volume 2, Issue 8, pp. August-2011.


Documents

Design and Finite Element Analysis of Disc Brake with different ... · with different materials for passenger car Snehita Kilari1, Tara Sasanka C2, K.G.S.V.Manikanta3 1,2Assistant