Determination of ultrasonic wave velocities and phase velocity dispersion curves of an Inconel 600 plate using resonant ultrasound spectroscopy and leaky Lamb waves

Ultrasonics ◽  
2004 ◽  
Vol 42 (1-9) ◽  
pp. 551-555 ◽  
Author(s):  
Young H Kim ◽  
Sung-Jin Song ◽  
Sung-Duk Kwon ◽  
Yong-Moo Cheong ◽  
Hyun-Kyu Jung
Keyword(s):  
Phase Velocity ◽  
Velocity Dispersion ◽  
Lamb Waves ◽  
Resonant Ultrasound Spectroscopy ◽  
Inconel 600 ◽  
Wave Velocities ◽  
Phase Velocity Dispersion ◽  
Leaky Lamb Waves ◽  
Resonant Ultrasound

scholarly journals Increasing contribution of grain boundary compliance to polycrystalline ice elasticity as temperature increases

2018 ◽  
Vol 64 (246) ◽  
pp. 669-674
Author(s):  
COLIN M. SAYERS
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Orientation Distribution ◽  
Resonant Ultrasound Spectroscopy ◽  
Wave Velocities ◽  
Polycrystalline Ice ◽  
Resonant Ultrasound ◽  
Increasing Temperature ◽  
Shear Compliance

ABSTRACTMeasured elastic stiffnesses of ice polycrystals decrease with increasing temperature due to a decrease in grain boundary stiffness with increasing temperature. In this paper, we represent grain boundaries as imperfectly bonded interfaces, across which traction is continuous, but displacement may be discontinuous. We express the additional compliance due to grain boundaries in terms of a second-rank and a fourth-rank tensor, which quantify the effect on elastic wave velocities of the orientation distribution as well as the normal and shear compliances of the grain boundaries. Measurement of the elastic stiffnesses allows determination of the components of these tensors. Application of the method to resonant ultrasound spectroscopy measurements made on ice polycrystals enables determination of the ratio BN/BS of the normal to shear compliance of the grain boundaries, which are found to be more compliant in shear than in compression. The ratio BN/BS is small at low temperatures, but increases as temperature increases, implying that the normal compliance increases relative to the shear compliance as temperature increases.

scholarly journals The Lamb waves phase velocity dispersion evaluation using an hybrid measurement technique

2018 ◽  
Vol 184 ◽  
pp. 1156-1164 ◽  
Author(s):  
L. Draudviliene ◽  
H. Ait Aider ◽  
O. Tumsys ◽  
L. Mazeika
Keyword(s):  
Phase Velocity ◽  
Measurement Technique ◽  
Velocity Dispersion ◽  
Lamb Waves ◽  
Phase Velocity Dispersion

New techniques for the determination of surface wave phase velocities

1968 ◽  
Vol 58 (3) ◽  
pp. 1021-1034 ◽  
Author(s):  
S. Bloch ◽  
A. L. Hales
Keyword(s):  
Phase Velocity ◽  
Rayleigh Waves ◽  
World Wide ◽  
Velocity Dispersion ◽  
Cross Product ◽  
New Techniques ◽  
Phase Velocities ◽  
Phase Velocity Dispersion ◽  
The World

abstract A number of new techniques have been developed for the determination of phase velocities from the digitized seismograms from pairs of stations. One of these techniques is to Fourier analyze the sum (or difference) of the two seismograms after time shifting in steps to correspond to steps in phase velocity. The amplitude of the summed seismogram is a maximum for any particular period when both seismograms are in phase at that period. Another method is to pass both seismograms through a narrow bandpass digital filter centered at various periods and form the cross product of the filtered seismograms, after time shifting. The average of the resultant time series is a maximum when the two signals are in phase. The computer output is a matrix consisting of amplitudes or averages as a function of phase velocity and period. The phase velocity dispersion is determined from the contoured matrix. Using these techniques, interstation phase velocities of Rayleigh waves have been determined for the “World Wide Network Standard Stations” at Pretoria, Bulawayo and Windhoek. The method using cross-products is the most efficient.

scholarly journals Metrological Performance of Hybrid Measurement Technique Applied for the Lamb Waves Phase Velocity Dispersion Evaluation

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 45985-45995 ◽  
Author(s):  
Lina Draudviliene ◽  
Asta Meskuotiene ◽  
Olgirdas Tumsys ◽  
Liudas Mazeika ◽  
Vykintas Samaitis
Keyword(s):  
Phase Velocity ◽  
Measurement Technique ◽  
Velocity Dispersion ◽  
Lamb Waves ◽  
Phase Velocity Dispersion ◽  
Metrological Performance

Finite-Difference Modeling and Characteristics Analysis of Love Waves in Anisotropic-Viscoelastic Media

2021 ◽  
Author(s):  
Shichuan Yuan ◽  
Zhenguo Zhang ◽  
Hengxin Ren ◽  
Wei Zhang ◽  
Xianhai Song ◽  
...  
Keyword(s):  
Finite Difference ◽  
Phase Velocity ◽  
Velocity Dispersion ◽  
Love Waves ◽  
Velocity Anisotropy ◽  
Viscoelastic Media ◽  
Phase Velocities ◽  
Phase Velocity Dispersion ◽  
Anisotropic Elastic ◽  
Attenuation Anisotropy

ABSTRACT In this study, the characteristics of Love waves in viscoelastic vertical transversely isotropic layered media are investigated by finite-difference numerical modeling. The accuracy of the modeling scheme is tested against the theoretical seismograms of isotropic-elastic and isotropic-viscoelastic media. The correctness of the modeling results is verified by the theoretical phase-velocity dispersion curves of Love waves in isotropic or anisotropic elastic or viscoelastic media. In two-layer half-space models, the effects of velocity anisotropy, viscoelasticity, and attenuation anisotropy of media on Love waves are studied in detail by comparing the modeling results obtained for anisotropic-elastic, isotropic-viscoelastic, and anisotropic-viscoelastic media with those obtained for isotropic-elastic media. Then, Love waves in three typical four-layer half-space models are simulated to further analyze the characteristics of Love waves in anisotropic-viscoelastic layered media. The results show that Love waves propagating in anisotropic-viscoelastic media are affected by both the anisotropy and viscoelasticity of media. The velocity anisotropy of media causes substantial changes in the values and distribution range of phase velocities of Love waves. The viscoelasticity of media leads to the amplitude attenuation and phase velocity dispersion of Love waves, and these effects increase with decreasing quality factors. The attenuation anisotropy of media indicates that the viscoelasticity degree of media is direction dependent. Comparisons of phase velocity ratios suggest that the change degree of Love-wave phase velocities due to viscoelasticity is much less than that caused by velocity anisotropy.

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