Results 281 to 290 of about 32,268 (336)
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Chirp excitation of ultrasonic guided waves
Ultrasonics, 2013Most ultrasonic guided wave methods require tone burst excitations to achieve some degree of mode purity while maintaining temporal resolution. In addition, it is often desirable to acquire data using multiple frequencies, particularly during method development when the best frequency for a specific application is not known.
Michaels, Jennifer E. +3 more
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Ultrasonic guided wave vibration formulation
AIP Conference Proceedings, 2012A novel transient-guided-wave-based approach to predicting natural vibration frequencies and mode shapes of a semi-infinite plate has been developed. This theory uses the orthogonal propagating and evanescent guided wave modes to fully satisfy the elasticity structural vibration boundary value problem for the structure.
C. Borigo, F. Yan, Y. Liang, J. L. Rose
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Guided wave helical ultrasonic tomography of pipes
The Journal of the Acoustical Society of America, 2003Ultrasonic guided waves have been used for a wide variety of ultrasonic inspection techniques. We describe here a new variation called helical ultrasound tomography (HUT) that uses guided ultrasonic waves along with tomographic reconstruction algorithms that have been developed by seismologists for what they call “cross borehole” tomography.
Kevin R, Leonard, Mark K, Hinders
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Non-contact ultrasonic guided wave inspection of rails
SPIE Proceedings, 2013The University of California at San Diego (UCSD), under a Federal Railroad Administration (FRA) Office of Research and Development (R&D) grant, is developing a system for high-speed and non-contact rail integrity evaluation. A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection, in pair with a ...
Nguyen, T. V. +5 more
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Ultrasonic guided wave tomography for ice detection
Ultrasonics, 2016Of great concern for many structures, particularly critical sections of rotary and fixed wing aircrafts, is the ability to detect ice either on grounded or in-flight vehicles. As a consequence, some work is reported here that could be useful for a variety of different industries where ice formation is an important problem.
Xiang, Zhao, Joseph L, Rose
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Ultrasonic guided waves in bone
The Journal of the Acoustical Society of America, 2008Recent progress in quantitative ultrasound (QUS) has shown increasing interest towards measuring long bones by ultrasonic guided waves. This technology is widely used in the field of non-destructive testing and evaluation of different waveguide structures.
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Ultrasonic guided-waves characterization with warped frequency transforms
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2008Guided wave (GW) dispersion curves can be extracted from a time-transient measurement by means of timefrequency representations (TFRs). Unfortunately, any TFR is subject to the time-frequency uncertainty principle. This, in general, limits the capability of TFRs to characterize closely spaced guided modes over a wide frequency range.
DE MARCHI, LUCA +3 more
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Guided ultrasonic waves in composite cylinders
Mechanics of Composite Materials, 2007The ultrasonic nondestructive evaluation of composite cylinders requires a thorough understanding of the propagation of waves in these materials. In this paper, the propagation of flexural and longitudinal guided waves in fiber-reinforced composite (FRC) rods with transversely isotropic symmetry properties is studied.
F. Honarvar, E. Enjilela, A. N. Sinclair
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Flexible piezopolymer ultrasonic guided wave arrays
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2006Ultrasonic guided wave technology is being applied to a variety of gas and liquid transmission pipeline inspection applications. There are a variety of promising transduction techniques used to excite longitudinal, torsional, and flexural modes in pipe. Some of the more common methods include electromagnetic-acoustic, magnetostrictive, and piezoceramic
T.R. Hay, J.L. Rose
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Guided Wave Electromagnetic Ultrasonic Tomography
2019The defect of the aluminum plate concerned in this chapter is mainly the plate thickness loss-type defect caused by corrosion, and the plate thickness change caused by such defects is relatively flat. When Lamb waves encounter such defects, the amplitudes of other modal waves generated by modal transformation are relatively small.
Songling Huang +4 more
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