Thermal Analysis Investigation of Brake

Discs Using CreoFinal Year Project Presentation

Saqib Ahmed (B00238797)Supervisor – David Kennedy

Overview of Project

This project touches upon the following modules –

Computer Aided Design (CAD) Thermal and Mechanical Design Race Engineering Analysis & Simulation Design Prototyping and Testing Motorsport Design Engineering Application Project

Overview of Problem for Vauxhall VX220 Brake DiscAssumptions can be made, where the thermal and mechanical loads will cause the brake disc to

deform/fatigue/crack.

Sources Regarding ProjectAuthor Title Year Overview Method

Y. Yildiz, M. Duzgun

Stress analysis of ventilated brake discs

using the finite element method

2010Stress Analysis of ventilated disc brakes via FEM, crack

formations

Experimental & Computational (Analytical)

V.M.M Thilak, R Krishnaraj, M Sakthivel, K Kanthavel,

Deepan Marudachalam, R Palani

Transient thermal and structural analysis of the rotor disc of disc brake

2011Transient Thermal Analysis

via ANSYSComputational & Analytical

Haripal Singh, Harshdeep Shergill

Thermal Analysis of Disc Brake Using Comsol

2012

Analysis of heat dissipation/heat generation during emergency braking,

comparison of three materials (conduction, convection &

radiation)

Computational & Analytical

Ameer Fareed Basha Shaik, Ch. Lakshmi Srinivas

STRUCTURAL AND THERMAL ANALYSIS OF DISC BRAKE WITH AND

WITHOUT CROSSDRILLED ROTAR OF RACE CAR

2012Thermal Analysis using

ANSYSComputational & Analytical

K. Sowjanya, S. SureshStructural analysis of disc

brake rotor2013

Creo Parametric model of brake, using ANSYS for Von Mises stress, deflection and

normal stresses

Computational & AnalyticalMetropolitan Police Brake Test – 50mph to 0mph 50 times (http://www.fleetnews.co.uk/news/2004/11/2/fleet-in-focus-the-met/18004/)

Main Research• Modelling of Problem• Experiment • Mechanical/Thermal Loading Validation • FEA of Brake Disc Designs

Modelling of Problem

Original VX220 Modified

Experiment on Vehicle (Heat Rise)

FL FR Non-Contact

∆T (oC)Initial Temp 20.6 20.2 IR (oC)

  Before After  

Run 1 20.2 23.5 3.3Run 2 25.9 30.3 4.4Run 3 23.9 32.4 8.5

Ek = 1/2mv2

Ek = Q = mC∆TSince mC = constant,

∆T directly proportional to Ek

Q = mC∆T∆T = 8.5 ≈ 129171.8 J

Validation (Mechanical Clamp Force)Front Force Calculations

Pad Contact Area (mm) 46.2 mm

Effective Disc Rad (mm) 120.9 mm

  0.1209 m     

Clamp Force, F 12688 NPer Side of Brake

Disc 6343.8 N

• Corner weights Calculated• 65-35 Front-Rear Brake

Balance• Disc Dia – 288 mm

Area 1 = 11145.5mmArea 2 = 14537.0mm

Area of Webbing = 3391.5mm

Validation (Mechanical Clamp Force)

10% Leigh-way for FEAStress found on model –

3.7744MPa

Hand Calculations

Validation (Thermal Stress Analysis)

Cast iron 4.5% C, ASTM A-48

Yield Strength = 130MPa

Ultimate Tensile Strength = 200 MPaOriginal VX220 Modifie

d

Validation (Thermal Stress Analysis)

OriginalMaxStress = 2738 MPa

Realistic = 1643MPa

VX220MaxStress = 1212.18

MPaRealistic = 727.317 MPa

ModifiedMaxStress = 1305.11MPa

Realistic = 783.072 MPa

FE Analysis of Brake Discs

Mechanical plus Thermal Load Cases

Consider the bolt holes added to the model since this will allow the model to be free to rotate around in the z-axis

Angular Velocity and Acceleration calculation required

Consider the scaling of results (very important!)

Problems and Limitations of Project

Working out exact values for the analysis Centre of Gravity of vehicle Exact calibration of the heat gun

Limitations with CAD/FEA Software no underlying shells or beams in the mechanical & thermal analysis Fine details aborting analysis on Creo Simulate

Discussion & Conclusion

Discussion To be completed - Timeline of Project Assumptions from Thermal & Mechanical Analysis

Conclusion• Modelling of Problem• Experiment • Mechanical/Thermal Loading Validation • FEA of Brake Disc Designs

Future Research

Choice of materials (isotopes) Centre of Gravity of Vehicle Experiment (knife-edge) Implementing dimensional analysis Using a different FEA software which is more suitable (Comsol,

ANYSYS, ABAQUS CAE) More demanding physical test (Metropolitan Police) Physical modelling of modified brake design in controlled conditions Manufacturing methods and heat treatment to components

Thank you for listening!

Any Questions?