Results 291 to 300 of about 16,283 (340)

Pressure Vessels Inspections Using Ultrasonic Phased Arrays

Ultrasonic Nondestructive Evaluation for Material Science and Industries, 2003
Phased arrays offer significant technical advantages for weld inspections over conventional ultrasonics. The phased array beams can be steered, scanned, swept and focused electronically. Beam steering permits the selected beam angles to be optimized ultrasonically by orienting them perpendicular to the predicted defects, especially Lack of Fusion ...
M.D.C. Moles, F. Jacques, N. Dube
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Optimization of Ultrasonic Phased Arrays

1998
Ultrasonic phased arrays are an emerging technology in nondestructive evaluation (NDE) applications. A phased array is a multi-element piezo-electric device whose elements are individually excited by electric pulses at programmed delay times [1]. Such a delay scheme allows electronically controlled dynamic beam control.
Wooh, Shi-Chang, Shi, Yijun
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Composite material ultrasonic phased array testing

AIP Conference Proceedings, 2019
This thesis discusses the results of an ultrasound testing of a fiberglass plate using a flaw detector with phased antenna arrays. Fiber-reinforced laminated composite materials are widely used in modern light-weight structures. Non- destructive experiments carried out on the composite plate with artificial defects. The examined 5 mm sample was made of
N. A. Ryngach, A. V. Emirov
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FUNDAMENTALS OF ULTRASONIC PHASED ARRAYS

Modern Physics Letters B, 2008
It is shown that the wave field of an ultrasonic linear array is closely related to that of an equivalent single element transducer. Using this relationship, it is demonstrated how one can construct a simple and efficient ultrasonic beam model for the wave field of a steered linear array.
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Phase Aberration Correction of Ultrasonic Phased Array Signals

2008 Congress on Image and Signal Processing, 2008
By properly adjusting the time delays, phased arrays can dynamically phase-steer and focus the ultrasonic beams. But phase aberration due to perturbation of system and materials degrade ultrasound performance by disrupting the ultrasound beam focus.
Xia Zhao, Zhaoba Wang, Bin Liu
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Element parameters for ultrasonic phased arrays

AIP Conference Proceedings, 2002
The industrial use of ultrasonic phased arrays is limited by several factors, such as budget, coverage, beam steering required, as well as the limitations of array manufacture. Only at high frequencies does the minimum array size become a functional limitation.
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Ultrasonic backscatter measurements using phased array ultrasonic transducers

The Journal of the Acoustical Society of America
Diffuse ultrasonic backscatter techniques are used to characterize microstructures and work well when grain scattering is confined within the single-scattering regime. When effects from higher-order scattering are present within the measurements, grain sizes are often overestimated.
Geoffrey R. Soneson, Nathanial Matz, Joseph A. Turner   +2 more
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Ultrasonic phased arrays for weld inspections

AIP Conference Proceedings, 2002
Ultrasonic phased arrays are well suited to weld inspections. Phased arrays can perform electronic scanning (where a scan pattern is rapidly multiplexed across a component), sectorial scanning (where the angle of inspection is varied), and combinations of these two.
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Ultrasonic phased array design for reduced crosstalk

The Journal of the Acoustical Society of America, 1998
In recent years, therapeutic ultrasound has received increased attention as a treatment modality for cancer therapy (hyperthermia) and heart arrythmia (ablation surgery). Ultrasonic phased arrays offer the benefit of noninvasive treatment with the flexibility of variable focus and beam steering. In designing and building these arrays, electromechanical
John Dodson, Karl Grosh
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Optical beamforming for ultrasonic phased arrays

LEOS '95. IEEE Lasers and Electro-Optics Society 1995 Annual Meeting. 8th Annual Meeting. Conference Proceedings, 2002
This paper describes potentially low cost, lightweight, and compact optical beamforming techniques for ultrasonic phased arrays. The use of a pair of tiny stamp-size low cost nematic liquid crystal (NLC) 2-D optical array devices for the transducer control sites allows compact, low control power beamforming for large (i.e., >128 element) 2-D transducer
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