The detection and identification of structural damages play a key role in the monitoring and servicing of structural safety and reliability. This paper applies the real-coded Genetic Algorithm to the crack detection problems of multi-cracked beams. The objective function of the Genetic Algorithm was minimized by comparing the changes of measured vibration data of cracked and uncracked structures with those of the analytical model before and after updating. In the analytical model, the massless spring was used to simulate the open crack in the beam. Based on the frequency changes and the mode shape changes caused by the presences of cracks, the analytical model is updated to find the crack locations and sizes. A thorough explanation on how to find the mutation rate, crossover rate, population size, and weights of the vibration data are also discussed.

Volume Subject Area:
Safety Engineering and Risk Analysis
Keywords:
Genetic algorithm, Crack detection, Vibration
Topics:
Crack detection, Fracture (Materials), Genetic algorithms, Vibration
1.
Doebling
S. W.
,
Farrar
C. R.
, and
Prime
M. B.
, “
Summary Review of Vibration-based Crack Identification Methods
,”
Shock and Vibration Digest
,
30
, pp.
91
–
105
,
1998
.
2.
Friswell M. I. and Mottershead J. E., Finite Element Model Updating in Structural Dynamics, Dordrecht: Kluwer Academic Publishers, 1995.
3.
Li
Q. S.
, “
Vibration Characteristics of Multi-step Beams with an Arbitrary Number of Cracks and Concentrated Masses
,”
Applied Acoustics
,
62
, pp.
691
–
706
,
2001
.
4.
Shifrin
E. I.
and
Ruotolo
R.
, “
Natural Frequencies of a Beam with an Arbitrary Number of Cracks
,”
Journal of Sound and Vibration
,
222
(
3
), pp.
409
–
423
,
1999
.
5.
Friswell
M. I.
,
Penny
J. E. T.
, and
Wilson
D. A. L.
, “
Using Vibration Data and Statistical Measures to Locate Crack in Structures
,”
The International Journal of Analytical and Experimental Modal Analysis
,
9
, pp.
239
–
254
,
1994
.
6.
Adams
R. D.
and
Cawley
P.
, “
A Vibration Technique for Non-Destructive Assessing the Integrity of Structures
,”
Journal of Mechanical Engineering Science
,
20
, pp.
93
–
100
,
1978
.
7.
Nandwana
B. P
,
Maiti
S. K.
 “
Detection of Location and Size of a Crack in Stepped Cantilever Beams Basel on Measurements of Natural Frequencies
,”
Journal of Sound and Vibration
,
203
(
3
), pp.
435
–
446
,
1997
.
8.
Gaunaris
G.
and
Dimarogonas
A. D.
 “
A Finite Element of a Cracked Prismatic Beam for Structural Analysis
,”
Computers and Structures
,
28
, pp.
309
–
313
,
1988
.
9.
Friswell
M. I.
,
Pennyb
J. E. T.
, and
Garvey
S. D.
, “
A Combined Genetic and Eigensensitivity Algorithm for the Location of Crack in Structures
,”
Computers and Structures
,
69
, pp.
547
–
556
,
1998
.
10.
Hao
H.
and
Xia
Y.
, “
Vibration-based Crack Detection of Structures by Genetic Algorithm
,”
Journal of Computing in Civil Engineering
,
16
, pp.
222
–
229
,
2002
.
11.
Mares
C.
and
Surace
C.
, “
An Application of Genetic Algorithms to Identify Crack in Elastic Structures
,”
Journal of Sound and Vibration
,
195
(
2
), pp.
195
–
215
,
1996
.
12.
Boltezar
M.
,
Strancar
B.
, and
Kuhelj
A.
, “
Identification of Transverse Crack Location in Flexural Vibrations of Free Free Beams
,”
Journal of Sound and Vibration
,
211
(
5
), pp.
729
–
734
,
1998
.
13.
Goldberg D.E., Genetic Algorithms in Search, Optimization and Machine Learning, Addison-Wesley Longman, Reading, Mass, 1989.
14.
Goldberg
D. E.
, “
Real-coded Genetic Algorithms, Virtual Alphabets, and Blocking
,”
Complex Systems
,
5
:
2
, pp.
139
–
167
,
1991
.
15.
Gudmundson
P.
, “
Eigenfrequency Changes of Structures Due to Cracks, Notches or Other Geometrical Changes
,”
Journal of Mechanical Physics Solids
,
30
(
5
), pp.
339
–
353
,
1982
.
16.
Hu
J.
and
Liang
R. Y.
, “
An Integrated Approach to Detection of Cracks Using Vibration Characteristics
,”
Journal of the Franklin Institute
,
330
(
5
), pp.
841
–
853
,
1993
.
17.
Harik
C.
,
Goldberg
D. E.
, and
Miller
, “
The Gambler’s Ruin Problem, Genetic Algorithms, and the Sizing of Population
,”
Evolutionary Computation
,
7
(
3
), pp.
231
–
253
,
1999
.
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