Work aimed towards the realisation of an embedded ultrasonic system for structural condition monitoring is described. Alien fibres embedded within carbon fibre reinforced composite plates could be utilised to guide ultrasound to strategic release points for the interrogation of the test sample, with minimal structural degradation. In particular, an array of fibre waveguides could be utilised to deliver periodic stresses to a plate-type structure to excite Lamb wave propagation. With such a system several problems need to be addressed. Ideally, single mode propagation in the fibre waveguide is required to provide increased control of the coupling of ultrasound from the waveguide to the desired Lamb wave mode. The choice of a suitable waveguide material and geometry is also crucial to ensure the guided ultrasound does not leak into the structure at undesirable locations and that the structural integrity of the test sample is maintained. Consequently, various waveguide configurations are investigated to establish an arrangement capable of meeting the system requirements. Finally, S0 Lamb wave generation and detection in a hard-setting polymer plate and a carbon fibre reinforced composite plate is demonstrated utilising embedded active acoustic waveguides sensors.
References
-
-
1)
-
G.D. Boyd ,
L.A. Coldren ,
R.N. Thurston
.
Acoustic waveguide with a cladded core geometry.
Appl. Phys. Lett.
,
31 -
34
-
2)
-
D. Atkinson ,
G. Hayward
.
Fibre waveguide transducers for Lamb wave NDE.
IEE Proc., Sci. Meas. Technol.
,
5 ,
260 -
268
-
3)
-
G.D. Boyd ,
L.A. Coldren ,
R.N. Thurston
.
Acoustic clad fibre delay lines.
IEEE Trans. Sonics Ultrasonics
,
246 -
252
-
4)
-
D. Alleyne ,
P. Cawley
.
A two dimensional fourier transform method for themeasurement of propagating multimode signals.
J. Acoust. Soc. Am.
,
3 ,
1159 -
1168
-
5)
-
B. Pavlakovic ,
M. Lowe ,
D. Alleyne ,
P. Cawley
.
Disperse: A general purpose program for creating dispersion curves.
Rev. Prog. Quant. Nondestruct. Eval.
,
85 -
192
-
6)
-
N.C. Nicholson ,
W.N. McDicken ,
T. Anderson
.
Waveguides in medical ultrasonics.
Ultrasonics
,
27 -
30
-
7)
-
Hyslop, J., Hayward, G.: `An experimental and theoretical investigation into the fluid-loadedperformance of 1-3 piezocomposite transducer array structures: with specific regard todevice surface displacement and beam profile', Proceedings of IEEE Ultrasonics Symposium, 1997, p. 907–910.
-
8)
-
F.L. Degertekin ,
B.T. Khuri-Yakub
.
Lamb wave excitation by Hertzian contacts with applications in NDE.
IEEE Trans. Ultrason. Ferroelectr. Freq. Control
,
4 ,
769 -
779
-
9)
-
B.Y. Kim ,
J.N. Blake ,
H.E. Engan ,
H.J. Shaw
.
All-fibre acousto-optic frequency shifter.
Opt. Lett.
,
389 -
391
-
10)
-
R.N. Thurston
.
Elastic waves in rods and clad rods.
J. Acoust. Soc. Am.
,
1 -
37
-
11)
-
R.S.C. Monkhouse ,
P.D. Wilcox ,
P. Cawley
.
Flexible interdigital PVDF Lamb wave transducers for the development of smart structures.
Rev. Prog. Quant. Nondestruct. Eval.
,
877 -
925
-
12)
-
E. Udd
.
Fibre optic smart structures.
Proc. IEEE
,
1 ,
60 -
67
-
13)
-
Sun, K.J., Winfree, W.P.: `Propagation of acoustic waves in a copper wire embedded in acuring epoxy', Proceedings of IEEE Ultrasonics Symposium, 1987, p. 439–442.
-
14)
-
Atkinson, D.: `Evaluation of an active acoustic waveguide sensor for embedded structural monitoring', , Ph.D., University of Strathclyde, Glasgow, Scotland, submitted January 2000.
-
15)
-
Jen, C.K., Chen, J.Y., Hoa, S.V., Nguyen, K.T., Legoux, J.G., Herbert, H.: `Clad buffer rods for in-situ process monitoring', Proceedings of IEEE Ultrasonics Symposium, 1997, p. 801–806.
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