New directional acoustic lens: V-groove lens
Proceedings of the IEEE Ultrasonics Symposium
Publ by IEEE, Piscataway, NJ, United States
MetadataShow full item record
Please cite this item using this persistent URLhttp://hdl.handle.net/11693/27800
A new directional acoustic lens is introduced. The geometry is very similar to the line-focus lens except the lens cavity, which is shaped as a groove with flat-bottom V cross section. The slanted planar edges of the groove are inclined in order to generate waves incident on the object surface at a critical angle. Hence, the edges of the groove act like two wedge transducers facing each other. The cross section of the lens is the same as that of the Lamb Wave Lens. Therefore, it enjoys the same sensitivity to surface wave excitations. On the other hand, since the cross section remains the same along one of the lateral directions, it has directional properties very similar to that of the Line Focus Beam Lens. The waves normally incident on the object surface generated from the flat-bottom, interfere with those at the critical angle, giving rise to a V(Z) effect. Calculated responses of the lens are presented for silicon (001) surface as a function of crystal orientation. The calculated curves are compared with measurement results. The leaky wave velocities are extracted from the measurement results using the conventional FFT algorithm. A new model based algorithm is proposed for extracting the velocity information from V(Z) data.
- Conference Paper 2294
Showing items related by title, author, creator and subject.
Identification of damaged wheat kernels and cracked-shell hazelnuts with impact acoustics time-frequency patterns Ince, N.F.; Onaran I.; Pearson, T.C.; Tewfik, A.H.; Cetin, A.E.; Kalkan H.; Yardimci, Y. (2008)A new adaptive time-frequency (t-f) analysis and classification procedure is applied to impact acoustic signals for detecting hazelnuts with cracked shells and three types of damaged wheat kernels. Kernels were dropped ...
Oltulu O.; Mamedov A.M.; Ozbay E. (Springer Verlag, 2017)The vast majority of acoustic wave propagation in phononic band studies has been usually carried out by scattering inclusions embedded in a viscoelastic medium, such as air or water. In this study, we present calculated ...
Can G.; Akbas C.E.; Cetin A.E. (Institute of Electrical and Electronics Engineers Inc., 2016)This paper proposes a vessel recognition and classification system based on vessel acoustic signatures. Teager Energy Operator (TEO) based Mel Frequency Cepstral Coefficients (MFCC) are used for the first time in Underwater ...