Disc Brake Rotor Selection through Finite Element Analysis...Rotor which studies about action on disc brake by analysis of the different forces acting on disc brake. Hopefully this

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Disc Brake Rotor Selection through Finite Element Analysis

Swapnil Umale 1,Dheeraj Varma

2

1Mechanical Engineering Dept -Padm. Dr. V.B. Kolte College of Engineering, Malkapur (M.S.)

2Mechanical Engineering Dept -Padm. Dr. V.B. Kolte College of Engineering, Malkapur (M.S.)

Abstract:These days’ technologies go beyond us. For automotive field, the technology of engine

develops very fast even the system of the car, luxury or comforts everything that develops by the

innovation of engineer. Although the engineer gives priority for safety measure, but most consumers

still have inadequate of knowledge in safety system. Thus safety is the first important thing we must

focus. This paper deals with “Force and thermal Analysis on Disc Brake and Optimization of Disc

Rotor” which studies about action on disc brake by analysis of the different forces acting on disc

brake. Hopefully this paper will help everyone to understand action force and friction force on the

disc brake and how disc brake works more efficiently, which can help to reduce the accident that

may happen in each day. Profile 3 is selected for further work as it gives better result.

Keyword:Disc brake, Disc profile optimization.

I. INTRODUCTION

A. Importance:

While braking, most of the kinetic energy are converted into thermal energy and increase the disc

temperature. This project consists of thermal stress analysis on pulsar brake disc rotor for steady state

and transient condition. The heat dissipated along the brake disc surface during the periodic braking

via conduction, convection and radiation. In order to get the stable and accurate result of element

size, time step selection is very important and all of these aspects are discussed in this paper. The

findings of this research provide a useful design tool to improve the brake performance of disc brake

system.

B. Need:

• A problem in Disc Brake occurs because of uneven stress & heat dissipation during braking of

two wheeler as follows:-

• Scarring, Cracking, Rusting, Poor stopping, noise, Vibration, Pulling, Grabbing, Dragging,

Pulsation etc

C. Principle of Working: When hydraulic pressure is applied to the calliper piston, it forces the inside pad to contact

the disc. As the pressure increases, the calliper moves to the right and cause the outside pad to

contact the disc. Braking force is generated by friction between the disc pads as they are squeezed

against the disc rotor. 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. The friction surface is

constantly exposed to the air, ensuring good heat dissipation, minimizing brake fade. It also allows

for self-cleaning as dust and water is thrown off, reducing friction difference.

Unlike drum brakes, disc brakes have limited self-energizing action making it necessary to apply

greater hydraulic pressure to obtain sufficient braking force. This is accomplished by increasing the

size of the caliper piston. The simple design facilitates easy maintenance and pad replacement.

International Journal of Recent Trends in Engineering & Research (IJRTER)

Volume 02, Issue 4; April - 2016 [ISSN: 2455-1457]


Figure 1. Principle of working of disc brake

D. Characteristics of Disc Brake: • Peak force – The peak force is the maximum decelerating effect that can be obtained. The

peak force is often greater than the traction limit of the tires, in which case the brake can cause a

wheel skid.

• Continuous power dissipation – Brakes typically get hot in use, and fail when the

temperature gets too high. The greatest amount of power (energy per unit time) that can be

dissipated through the brake without failure is the continuous power dissipation. Continuous

power dissipation often depends on e.g., the temperature and speed of ambient cooling air.

• Fade – As a brake heats, it may become less effective, called brake fade. Some designs are

inherently prone to fade, while other designs are relatively immune. Further, use considerations,

such as cooling, often have a big effect on fade.

• Smoothness – A brake that is grabby, pulses, has chatter, or otherwise exerts varying brake

force may lead to skids. For example, railroad wheels have little traction, and friction brakes

without an anti-skid mechanism often lead to skids, which increases maintenance costs and leads

to a "thump thump" feeling for riders inside.

• Power – Brakes are often described as "powerful" when a small human application force

leads to a braking force that is higher than typical for other brakes in the same class. This notion

of "powerful" does not relate to continuous power dissipation, and may be confusing in that a

brake may be "powerful" and brake strongly with a gentle brake application, yet have lower

(worse) peak force than a less "powerful" brake.

• Pedal feel – Brake pedal feel encompasses subjective perception of brake power output as a

function of pedal travel. Pedal travel is influenced by the fluid displacement of the brake and

other factors.

• Drag – Brakes have varied amount of drag in the off-brake condition depending on design of

the system to accommodate total system compliance and deformation that exists under braking

with ability to retract friction material from the rubbing surface in the off-brake condition.

• Durability – Friction brakes have wear surfaces that must be renewed periodically. Wear

surfaces include the brake shoes or pads, and also the brake disc or drum. There may be

tradeoffs, for example a wear surface that generates high peak force may also wear quickly.

• Weight – Brakes are often "added weight" in that they serve no other function. Further,

brakes are often mounted on wheels, and unstrung weight can significantly hurt traction in some

circumstances. "Weight" may mean the brake itself, or may include additional support structure.

• Noise – Brakes usually create some minor noise when applied, but often create squeal or

grinding noises that are quite loud.




E. Application:

• Brakes are used primarily in motor vehicles, in machinery and equipment

• Disc brakes are used aircraft, bicycles, railway

• Widely used in cars and trucks.

• The disc brake inertia is small, fast action, high sensitivity,

• The disc brakes on the new mine hoist brake.

• Adjustable braking torque

• The multi-rope friction hoist all use disc brakes.

F. Objectives: • The given disk brake rotor of its stability and rigidity (for this structural Analysis and coupled

Thermal analysis is carried out on a given disk brake rotor).

• Best combination of parameters of disk brake rotor like, wall thickness and material there by a

best combination will be suggested.

• Design of the rotor component for a disc brake system using load analysis, stress analysis and

thermal analysis system approach.

II. LITERATURE REVIEW

• Ali Belhocine et. all [1] studied the thermal behaviour of the full and ventilated brake discs of

the vehicles using computing code ANSYS. The modelling of the temperature distribution in the disc

brake is used to identify all the factors and the entering parameters concerned at the time of the

braking operation such as the type of braking, the geometric design of the disc and the used material.

The numerical simulation for the coupled transient thermal field and stress field is carried out by

sequentially thermal-structural coupled method based on ANSYS to evaluate the stress fields and

deformations which are established in the disc with the pressure on the pads. The results obtained by

the simulation are satisfactory when compared with those of the specialized literature

• G. Babukanth et. al. [2] studied 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 behaviour 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 behaviours (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 behaviours of the carbon-carbon

composites with excellent mechanical properties are also discussed.

• The paper of Atul sharma et. al. [3] explains Disc brake basics like, Disc brake, are often

used in automobile transmission system to stop moving machine. Due to space constraint and

performance requirement, disc brakes have fluctuating load characteristics, resulting in local stress

and deflections. Friction temperature in brake disc can cause material carbonization and debonding.

This research paper explains the design and finite element analysis (FEA) model of brake disc by

which deflections in X, Y, Z direction and Von-mises stress can be calculated by applying boundary

conditions. The FEA outcomes are correlated with experimental data. A good agreement, with 5%

discrepancy in the experimental data during the first engagement is obtained. The developed method

improves the understanding of the structural failure, modal prediction, operating conditions, and

reduces product development time and cost




• Amit Telang et. al. [4] work on the effect of SiC particle reinforcement and further its heat

treatment on Al alloy (ADC12) are studied in the application of automobile brake discs. ADC 12 is

synthesized by stir casting process and it’s composite with silicon carbide (SiC) in weight percentage

of 10% as the hard particle and its heat treated variety. The candidate materials have been compared

with tests on a rig developed for testing of brake discs under variety of operating conditions. The

brake disc test set-up is a facility developed for simulating on road brake disc operating conditions.

The brake disc test procedure for performance evaluation has been developed and formulated based

on the Bureau of Indian standards (IS-14664:1999) for the acceptability of results. For evaluation the

performance has been compared with the conventional steel brake disc with an emphasis on brake

torque. In general it is observed that the average brake torque for ADC12 alloy at all velocities and

brake force is lower than steel. The brake torque of the composites is higher than steel, the addition

of SiC particles increased material hardness and its brake torque. Heat treatment of the composite

material further increased the brake torque.

• The aim of this work was to investigate the temperature fields and also structural fields of the

solid disc brake during short and emergency braking with four different materials. The distribution of

the temperature depends on the various factors such as friction, surface roughness and speed. The

effect of the angular velocity and the contact pressure induces the temperature rise of disc brake. The

finite element simulation for two-dimensional model was preferred due to the heat flux ratio

constantly distributed in circumferential direction. We will take down the value of temperature,

friction contact power, nodal displacement and deformation for different pressure condition using

analysis software with four materials namely cast iron, cast steel, aluminium and carbon fibre

reinforced plastic. Presently the Disc brakes are made up of cast iron and cast steel. With the value at

the hand we can determine the best suitable material for the brake drum with higher life span. The

detailed drawings of all parts are to be furnished by Daniel Das. A et. al. [5]

• Oder, G. et. al. [6] present paper shows a thermal and stress analysis of a brake disc for

railway vehicles using the finite element method (FEM). Performed analysis deals with two cases of

braking; the first case considers braking to a standstill; the second case considers braking on a hill

and maintaining a constant speed. In both cases the main boundary condition is the heat flux on the

braking surfaces and the holding force of the brake callipers. In addition the centrifugal load1 is

considered.

III. MODELING OF PROFILES

Figure 2: Forces act on disc brake during rotation




A. Various Profiles for Testing:

Figure 3: Profile 1

Figure 4: Profile 2

Figure 5: Profile 3




Figure 6: Profile 4

Figure 7: Profile 5

IV. ANALYSIS FOR PROFILE SELECTION

Sample Analysis for Profile 1:

A. Static Analysis Results:

Figure 8: Deformation result of disc brake 1




Figure 9: Stress result of disc brake 1

B. Thermal Analysis:

Figure 10: Temperature distribution on disc 1

Figure 11: Heat flux for disc 1




Table 1.Results based on analysis carried out for profiles:

Profile

of Disc Deformation,mm

Stress,

MPa

Heat Flux,

W/mm2

1 0.0029405 13.149 0.56531

2 0.0053579 14.399 0.93465

3 0.0038928 20.209 1.0538

4 0.0028292 12.742 0.49042

5 0.0047418 13.326 0.58095

From above results it’s clear that profile 3 is giving higher heat flux among all profiles and hence its

best. Stresses are on higher side but are within allowable limit - Cast Iron material is used.

V. CONCLUSION & FUTURE SCOPE

A. Conclusion: - Disc profile plays important role in thermal distribution and should be carefully selected.

-The results we got for selected profile 3 are showing good improvement compare to other profiles.

B. Future Scope:

-Material Analysis can be done.

- Dynamic Analysis can be done.

- Modal Analysis (Vibrations) can be included for further improvement.

- Transient Thermal Analysis can be scope for further work.

REFERENCES 1. Ali Belhocine, Mostefa Bouchetara “Thermo-mechanical modelling of dry contacts in automotive disc brake” at

International Journal of Thermal Sciences 60 (2012) 161e170, 2012 Published by Elsevier Masson SAS.

2. G. Babukanth and M. Vimal Teja “Transient Analysis of Disk Brake By using Ansys Software” International

Journal of Mechanical and Industrial Engineering (IJMIE), ISSN No. 2231 –6477, Vol-2, Issue-1, 2012.

3. Atul sharma and M.L. Aggarwal “Deflection and stress Analysis of Brake Disc using Finite Element Method” at

Proceedings of the National Conference on Trends and Advances in Mechanical Engineering, YMCA University of

Science & Technology, Faridabad, Haryana, Oct 19-20, 2012.

4. Amit Telang, Ameenur Rehman1, Gajendra Dixit and Satyabrata Das “Effect of reinforcement and heat treatment

on the friction performance of Al Si alloy and brake pad pair” at Scholars Research Library Archives of Applied

Science Research, 2010, 2 (4): 95-102.

5. Daniel Das.A, Christo Reegan Raj.V, Preethy.S, Ramya Bharani.G “Structural and Thermal Analysis of Disc

Brake in Automobiles” at International Journal of Latest Trends in Engineering and Technology (IJLTET) ISSN:

2278-621X Vol. 2 Issue 3 May 2013.

6. Oder, G., Reibenschuh, M., Lerher, T., Sraml, M.; Samec, B.; Potrc, I. “Thermal And Stress Analysis Of Brake

Discs In Railway Vehicles” at International Journal of Advanced Engineering 3(2009)1, ISSN 1846-5900.

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Disc Brake Rotor Selection through Finite Element Analysis...Rotor which studies about action on disc brake by analysis of the different forces acting on disc brake. Hopefully this