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.