Project Work(Phase-II)Review-I

Name: K.MAHESH KUMARReg No:200821427Project Guide: Dr.K.Malar Mohan.Ph.D.,Assistant ProfessorAU-FRG Institute for CAD/CAMAnna UniversityChennai-25

Crack changes the dynamic behaviour of the

structure and by examining this change,

crack size and position can be identified

Extracting modal parameters like mode

shape, natural frequency and damping to

detect crack in brake disc.

Selection of disc brake that will be used or

tested in this project

Modeling the disc brake in Pro-E

Performing modal analysis in ANSYS v13.0

Performing Experimental Modal Analysis

using Shaker

Comparison between Simulation and

Experimental

The basic idea is that the modal parameters

are, by definition, functions of the physical

properties of components such as mass,

stiffness or modulus of elasticity and hence

of mechanical properties. This concept was

used mainly in the application of modal

testing

Physically, a crack of length 30mm to a depth

of 10mm in the disc brake is made by EDM of

wire size 0.25mm

In FEA, the crack width of 0.35mm of the

same length and depth is made using ANSYS.

Element Used for meshing is Shell65

Analysis Type: Modal

Mode Extraction Algorithm :Block Lanczos

Material Selected : Grey Cast Iron

Density : 6900 kg/m3

Modulus Of Elasticity : 110 Gpa

Poisson’s Ratio : 0.211

Mode

No

NatFreq (Hz)

Mode

No

NatFreq(Hz)

Mode

No

NatFreq(Hz)

Mode

No

NatFreq(Hz)

Mode

No

NatFreq(Hz)

1 0 11 58.353 21 169.62 31 323.87 41 453.29

2 0 12 91.72 22 205.85 32 326.27 42 456.84

3 1.12E-03 13 92.414 23 220.23 33 346.83 43 459.27

4 1.39E-02 14 100.68 24 240.32 34 349.75 44 463.52

5 1.84E-02 15 105.89 25 251.35 35 382.33 45 466.87

6 3.34E-02 16 107.54 26 252.13 36 406.91 46 477.23

7 21.823 17 109.65 27 262.55 37 418.22 47 483.37

8 22.037 18 156.22 28 265.48 38 435.66 48 484.56

9 48.391 19 166.22 29 289.67 39 448.08 49 491.13

10 58.23 20 169.12 30 294.73 40 453.28 50 493.36

Uncracked Disc Cracked Disc

Mode No Nat.Freq (Hz) Mode No Nat.Freq(Hz) % decrease

30 322.011 30 295.218 8.32

50 588.98 50 499.822 15.14

J.He , and Z.F.Fu, Modal Analysis, Oxford, Butterworth-

Heinemann,2001.

M.Z.Hassan, Brake disc performance:

FEA,Msc.Thesis,Coventry University,Coventry,UK,2004.

DJ Ewins: Modal Testing: Theory, Practice and Application,

Research Studies Press Ltd., New York(1984)

A.L.Gyenkenyesi,J.T.Sawichki and G.Y.Baaklini, “Vibration

Based Crack Detection in a Rotating Disk” Part I- Analytical

Study,NASA,2003.

Haileleoul Sahle, Cracked Detection in Rotating Disc,

MSc.Thesis, Addis Ababa University,2004.

J.C.Bae and J.A.Wickert 2000 Journal of Sound and Vibration

235(1),117-132.Free Vibration of Coupled Disk-Hat

Structures.