книги / 42
.pdfLITERATUR |
193 |
[128]S. Zeroug und L.B. Felsen. "Nonspecular re ection of beams from liquid-solid interfaces\. In: Journal of Nondestructive Evaluation 11.3 (1992), S. 263{278.
[129]A. Schoch. "Seitliche Versetzung eines total re ektierten Strahls bei Ultraschallwellen\. In: Acoustica 2 (1952), S. 18{19.
[130]F. Goos und H. Hanchen•. "Ein neuer und fundamentaler Versuch zur Totalre exion\. In: Annalen der Physik 436.7-8 (1947), S. 333{346.
[131]F. Goos und H. Lindberg-Hanchen•. "Neumessung des Strahlversetzungse ektes bei Totalre exion\. In: Annalen der Physik 440.3-5 (1949), S. 251{252.
[132]N. F. Declercq, J. Degrieck und O. Leroy. "The representation of 3D gaussian beams by means of inhomogeneous waves.\ In: Ultrasonics 42.1-9 (2004), S. 273{6.
[133]N. F. Declercq u. a. "The schoch e ect to distinguish between different liquids in closed containers.\ In: IEEE transactions on ultrasonics, ferroelectrics, and frequency control 51.10 (2004), S. 1354{ 7.
[134]N. F Declercq. "Fast beating null strip during the re ection of pulsed Gaussian beams incident at the Rayleigh angle.\ In: Ultrasonics 44 Suppl 1 (2006), e1447{51.
[135]H. K. V. Lotsch. "Die Strahlversetzung bei Totalre exion: Der GoosHanchen• E ekt\. Diss. 1970, S. 114.
[136]O. I. Diachok und W. G. Mayer. "Velocity measurements of lateral beam displacement upon re ection\. In: IEEE Transaction on Sonics and Ultrasonics 16.4 (1969), S. 219{221.
[137]T.J. Plona und W.G. Mayer. "Phase of ultrasonic re ection at Rayleigh angle incidence\. In: Applied Physics Letters 23.10 (1973), S. 536{ 538.
[138]W. G. Neubauer. "Ultrasonic re ection of a bounded beam at Rayleigh and critical angles for a plane liquid-solid interface\. In: Journal of Applied Physics 44.1 (1973), S. 48{55.
[139]W. G. Neubauer und L. R. Dragonette. "Measurement of Rayleigh phase velocity and estimates of shear speed by schlieren visualization\. In: Journal of Applied Physics 45.2 (1974), S. 618.
[140]M. A. Breazeale, L. Adler und G. W. Scott. "Interaction of ultrasonic waves incident at the Rayleigh angle onto a liquid-solid interface\. In: Journal of Applied Physics 48.2 (1977), S. 530{537.
194 |
LITERATUR |
[141]L. Adler, M. de Billy und G. J. Quentin. "Excitation of ultrasonic Rayleigh leaky waves at liquid-solid interface for general angle incidence\. In: Journal of Applied Physics 53.12 (1982), S. 8756{8758.
[142]E. Lamkan u. a. "Finite element analysis of transmission of leaky Rayleigh waves at the extremity of a uid-loaded thick plate\. In:
Journal of Applied Physics 101.11 (2007), S. 114907.
[143]N. F. Declercq und E. Lamkan . "Study by means of liquid side acoustic barrier of the in uence of leaky Rayleigh waves on bounded beam re ection\. In: Applied Physics Letters 93.5 (2008), S. 054103.
[144]E. Lamkan u. a. "Numerical study of Rayleigh wave transmission through an acoustic barrier\. In: Journal of Applied Physics 105.11 (2009), S. 114902.
[145]A. Schoch. "Der Durchgang von Ultraschall durch Platten\. In: Il Nuovo Cimento 7.S2 (1950), S. 302{306.
[146]K. Van Den Abeele und O. Leroy. "Complex harmonic wave scattering as the framework for investigation of bounded beam re ection and transmission at plane interfaces and its importance in the study of vibrational modes\. In: The Journal of the Acoustical Society of America 93.1 (1993), S. 308.
[147]K. Van Den Abeele und O. Leroy. "On the in uence of frequency and width of an ultrasonic bounded beam in the investigation of materials: Study in terms of heterogeneous plane waves\. In: The Journal of the Acoustical Society of America 93.5 (1993), S. 2688.
[148]J. Pott und J. G. Harris. "Scattering of an acoustic Gaussian beam for a uid-solid interface\. In: The Journal of the Acoustical Society of America 76.6 (1984), S. 1829{1836.
[149]S. Zeroug und L. B Felsen. "Nonspecular re ection of twoand threedimensional acoustic beams from uid-immersed plane-layered elastic structures\. In: The Journal of the Acoustical Society of America
95.6 (1994), S. 3075{3089.
[150] N. F Declercq u. a. "The radiation mode theory in ultrasonics.\ In: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 52.5 (2005), S. 802{8.
[151]J. M. Claeys und O. Leroy. "Re ection and transmission of bounded sound beams on half-spaces and through plates\. In: The Journal of the Acoustical Society of America 72 (1982), S. 585.
LITERATUR |
195 |
[152]O. Leroy, G. Quentin und J. M. Claeys. "Energy conservation for inhomogeneous plane waves\. In: The Journal of the Acoustical Society of America 84.1 (1988), S. 374.
[153]V. V. Krylov. "Surface properties of solids and surface acoustic waves: Application to chemical sensors and layer characterization\. In: Applied Physics A Materials Science & Processing 61.3 (1995),
S.229{236.
[154]G. Fischerauer. "Modeling and signal processing approaches for SAW chemical sensors\. In: Proceedings Sensor + Test Conference SENSOR 2011. 2011, S. 47{52.
[155]S. W. Wenzel und R. M. White. "A multisensor employing an ultrasonic Lamb-wave oscillator\. In: IEEE Transactions on Electron Devices 15.6 (1988), S. 735{743.
[156]S. W. Wenzel, B. A. Martin und R. M. White. "Generalized Lambwave multisensor\. In: Proceedings IEEE Ultrasonics Symposium (1988),
S.563{567.
[157]J. W. Grate, S. W. Wenzel und R. M. White. "Flexural plate wave devices for chemical analysis\. In: Analytical Chemistry 63.15 (1991),
S.1552{1561.
[158]H. F. Tiersten und B. K. Sinha. "A perturbation analysis of the attenuation and dispersion of surface waves\. In: Journal of Applied Physics 49.1 (1978), S. 87.
[159]C. McMullan u. a. "Modelling of the mass sensitivity of the Love wave device in the presence of a viscous liquid\. In: Journal of Physics D: Applied Physics 33.23 (2000), S. 3053{3059.
[160]F. Lucklum und B. Jakoby. "Novel magnetic-acoustic resonator sensors for remote liquid phase measurement and mass detection\. In:
Sensors and Actuators A: Physical 145-146 (2008), S. 44{51.
[161]B. Henning u. a. "Computer-assisted design of transducers for ultrasonic sensor systems\. In: Measurement Science and Technology
20.12 (2009), S. 124012.
[162]S. Sorohan u. a. "Numerical extraction of dispersion curves for Lamb wave inspections on complex structures\. In: Proceedings of the International Congress on Ultrasonics, Vienna, 2007. 3. 2007, Paper ID 1438.
[163]Y. S. Cho. "Experimental and numerical studies using NDT , SASW , in multi-layer slabs\. In: Proceedings of the International Congress on Ultrasonics 2007, Vieenna. 2007, Paper ID 1283.
196 |
LITERATUR |
[164]U. Stelzmann, C. Groth und G. Muller•. FEM fur• Praktiker - Band 2. Expert Verlag, 2006.
[165]Ansys. Ansys Structural Analysis Guide. 4th Edition. 1998.
[166]G. Lindner u. a. "Detection of coatings and measurement of coating thickness on technical substrates using surface acoustic waves in a waveguide con guration\. In: Proceedings Sensor + Test Conference SENSOR 2009. i. 2009, S. 35{40.
[167]D. Friedrich u. a. "Acoustic On-Line Monitoring of Chemical Reactions in Liquids with Integrated Temperature Compensation\. In: Sensor Letters 9.2 (2011), S. 714{716.
[168]S. Toda u. a. "An ultrasonic nondestructive technique for evaluating layer thickness in human teeth\. In: Sensors and Actuators A: Physical 125.1 (2005), S. 1{9.
[169]L. Zhou, J.-F. Manceau und F. Bastien. "In uence of gases on Lamb waves propagations in resonator\. In: Applied Physics Letters 95.22 (2009), S. 223505.
[170]M. Schmitt u. a. "Online detection of mikrobial bio lm formation by means of acoustic Lamb waves\. In: Vereinigung fur• Allgemeine und Angewandte Mikrobiologie Jahrestagung 2011. 2011.
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197 |
A |
Anhang |
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A.1 |
Dispersionsberechnungen |
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A.1.1 Transfer-Matrix-Methode |
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Die Feldmatrix |
A , und die Ausbreitungsmatrix |
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ratur ausfuhrlich• |
hergeleitet [25, 74]. An dieser Stelle sollen die Matrixele- |
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mente aufgelistet werden, die zur Berechnung der Re exionskoe zienten und der Dispersionund Dampfungsdiagramme• verwendet werden. Es wird die Schreibweise von Lowe angewandt [25, 74].
In der Transfer-Matrix-Methode kann die Feldmatrix |
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den durch: |
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beschrieben wer- |
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g11 |
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i L |
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2i kcsC2 |
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hierbei werden zur kompakten Schreibweise die Ausdrucke• |
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C1 = !2=cl2 |
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i(!2=cl2 |
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g1 = e |
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1=2 g2 = ei(!2=c2s k2) x2 ;
L = !2 2c2sk2
verwendet. In den obigen Gleichungen steht ! fur• die Kreisfrequenz, cl fur• die longitudinale Schallgeschwindigkeit, cs fur• die Scherwellenschallgeschwindikeit, k fur• die Wellenzahl der Lambwelle und x2 fur• die Koordinate der Grenzschicht der Schicht. Fur• jede Schicht wird ein eigenes Koordinatensystem an der oberen Grenzschicht de niert. Somit hat die obere Grenze einer Schicht stets die Koordinate x2 = 0 und die untere Grenze die Koordinate x2 = d. Hierbei ist d die jeweilige Schichtdicke.
Die Ausbreitungsmatrix F ist die 4x4 Matrix
198 |
A ANHANG |
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f11 |
f12 |
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(155) |
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6f41 |
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f31 |
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mit den Elementen
f11
f12
f13
f14
f21
f22
f23
f24
f31
f32
f33 f34
f41
f42 f43 f44
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;(156)
;
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=f21;
=f11;
wiederum nden zur kompakten Darstellung die Ausdrucke• von Gleichung 154 Verwendung.
A.1 Dispersionsberechnungen |
199 |
A.1.2 Global-Matrix-Methode fur• ein Zweischichtsystem im Vakuum
Die ausfuhrlichen• Gleichungen der Global-Matrix-Methoden fur• ein Zweischichtsystem im Vakuum werden in der Literatur hergeleitet und diskutiert [24, 68]. An dieser Stelle werden die Matrixelement fur• die charakteristische Determinante zusammengefasst, die fur• die Berechnungen in dieser Arbeit eingesetzt werden. Es wird die Schreibweise nach Rose verwendet [24],
a11 |
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a12 |
= (1)kl(1)2 + 2 (1)Kl(1)2; |
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a13 |
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a14 |
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a15 = A16 = A17 = A18 = 0; |
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a21 |
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a22 |
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a23 |
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Ks(1)2 |
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a |
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a31 |
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a32 |
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a33 |
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a34 |
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a35 |
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a36 |
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a37 |
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a38 |
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200 |
A ANHANG |
a41 = keiKl(1)h1 ; a42 = ke iKl(1)h1 ;
a43 = Ks(1)eiKs(1)h1 ; a44 = Ks(1)e iKs(1)h1 ; a45 = keiKl(2)h1 ;
a46 = ke iKl(2)h1 ; a47 = Ks(2)eiKs(2)h1 ;
a48 = Ks(2)e iKs(2)h1 ;
a51 = (1)kl(1)2 + 2 (1)Kl(1)2 eiKl(1)h1 ; a52 = (1)kl(1)2 + 2 (1)Kl(1)2 e iKl(1)h1 ; a53 = 2 (1)kKs(1)eiKs(1)h1 ;
a54 = 2 (1)kKs(1)e iKs(1)h1 ;
a55 = (2)kl(2)2 + 2 (2)Kl(2)2 eiKl(2)h1 ; a56 = (2)kl(2)2 + 2 (2)Kl(2)2 e iKl(2)h1 ; a57 = 2 (2)kKs(2)eiKs(2)h1 ;
a58 = 2 (2)kKs(2)e iKs(2)h1 ; a61 = 2 (1)kKl(1)eiKl(1)h1 ; a62 = 2 (1)kKl(1)e iKl(1)h1 ;
a63 = (1) Ks(1)2 k2 eiKs(1)h1 ; a64 = (1) Ks(1)2 k2 e iKs(1)h1 ; a65 = 2 (2)kKl2eiKl(2)h1 ;
a66 = 2 (2)kKl2e iKl(2)h1 ;
a67 = (2) Ks(2)2 k2 eiKs(2)h1 ; a68 = (2) Ks(2)2 k2 e iKs(2)h1 ;
A.1 Dispersionsberechnungen |
201 |
a71 = A72 = A73 = A74 = 0;
a75 = (2)kl(2)2 + 2 (2)Kl(2)2 eiKl2h2 ; a76 = (2)kl(2)2 + 2 (2)Kl(2)2 e iKl2h2 ; a77 = 2 (2)kKs(2)eiKs(2)h2 ;
a78 = 2 (2)kKs(2)e iKs(2)h2 ;
a81 = A82 = A83 = A84 = 0;
a85 = 2 (2)kKl(2)eiKl(2)h2 ; a86 = 2 (2)kKl(2)e iKl(2)h2 ;
a87 = (2) Ks(2)2 k2 eiKs(2)h2 ; a88 = (2) Ks(2)2 k2 e iKs(2)h2 :
In den Matrixelementen bedeutet eine Klammer mit einer Zahl von 1 oder 2 nach einer physikalischen Gro• e, dass diese Gro• e in Abhangigkeit• vom Material der Schicht steht. (1) verweist auf die erste Schicht und (2) verweist auf die zweite Schicht des Zweischichtensystems. In den Matrixelementen sind die gesuchten Wellenzahlen der Lambwellen k, die Wellenzahl der logitudinalen Schallwelle der n-ten Schicht kl(n) und die Wellenzahl der transversalen Schallwelle der n-ten Schicht ks(n) und die beiden Gro• en Kl(n) und Ks(n) enthalten. Dies lassen sich ausdrucken• durch:
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hierbei ist ! die Kreisfrequenz, c die Phasengeschwindigkeit der Lambwellenmode, cl(n) die longitudinale Schallgeschwindigkeit und cl(n) die transversale Schallgeschwindigkeit in der n-ten Schicht. Desweiteren sind in den Matrixelementen die Lamekonstanten (n) und (n) der n-ten Schichten und die beiden Schichthohen• h1 und h2 enthalten.
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A ANHANG |
A.1.3 Global-Matrix-Methode fur• ein Zweischichtsystem zwischen zwei Halbr•aumen
0
Die Determinatenelemente B der Global-Matrix-Methode eines Zweischichtensystems (S1 und S2) eingebettet zwischen zwei elastischen Halbraumen• (H1 und H2) sind der Literatur entnommen [25, 68, 74]. Es wird die Schreibweise von Lowe angewandt [25, 74].
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Da bei der Abstrahlung nur logitudinale und transversale Schallwellen die beiden Halbraume• verlassen und keine logitudinale und transversale Schallwellen auf das Zweischichtsystem einfallen, mussen• die Matrizen der Schallausbreitung in den Halbraumen• um zwei Spalten reduziert werden. Fur• den oberen Halbraum fallen die erste und die dritte Spalte und fur• den unteren Halbraum die zweite und die vierte Spalte weg. Somit gelten im Fall der Abstrahlung bei einem Zweischichtsystem die Gleichungen
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und
