Phased array focusing with guided waves in a viscoelastic coated hollow cylinder

2007 ◽  
Vol 121 (4) ◽  
pp. 1945-1955 ◽  
Author(s):  
Wei Luo ◽  
Joseph L. Rose
Keyword(s):  
Hollow Cylinder ◽  
Guided Waves ◽  
Phased Array

scholarly journals Numerical Investigation of Excitation of Various Lamb Waves Modes in Thin Plastic Films

2022 ◽  
Vol 12 (2) ◽  
pp. 849
Author(s):  
Rymantas Jonas Kazys ◽  
Justina Sestoke ◽  
Egidijus Zukauskas
Keyword(s):  
Numerical Investigation ◽  
Lamb Wave ◽  
Guided Waves ◽  
Phased Array ◽  
Ultrasonic Transducer ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Plastic Films ◽  
Thin Plastic ◽  
Wave Modes

Ultrasonic-guided waves are widely used for the non-destructive testing and material characterization of plates and thin films. In the case of thin plastic polyvinyl chloride (PVC), films up to 3.2 MHz with only two Lamb wave modes, antisymmetrical A0 and symmetrical S0, may propagate. At frequencies lower that 240 kHz, the velocity of the A0 mode becomes slower than the ultrasonic velocity in air which makes excitation and reception of such mode complicated. For excitation of both modes, we propose instead a single air-coupled ultrasonic transducer to use linear air-coupled arrays, which can be electronically readjusted to optimally excite and receive the A0 and S0 guided wave modes. The objective of this article was the numerical investigation of feasibility to excite different types of ultrasonic-guided waves, such as S0 and A0 modes in thin plastic films with the same electronically readjusted linear phased array. Three-dimensional and two-dimensional simulations of A0 and S0 Lamb wave modes using a single ultrasonic transducer and a linear phased array were performed. The obtained results clearly demonstrate feasibility to excite efficiently different guided wave modes in thin plastic films with readjusted phased array.

Source Influence for Focusing Potential of Guided Waves in Hollow Cylinders by Using a Circumferential Phased Array

2004 ◽  
Author(s):  
Li Zhang ◽  
Brian J. Gavigan ◽  
Joseph L. Rose
Keyword(s):  
Time Delays ◽  
Nuclear Power ◽  
Guided Waves ◽  
Phased Array ◽  
Angular Displacement ◽  
Excitation Source ◽  
Natural Gas Pipelines ◽  
Contour Plots ◽  
Array Position ◽  
Steam Pipes

The phased array focusing technique is being developed with the intent to inspect hundreds of feet of pipeline from a single array position. The single array position is beneficial if access to a pipe is limited, e.g. steam pipes onboard U.S. Naval ships, nuclear power plant pipes, oil and natural gas pipelines. The steam pipes have a protective coating which would ordinarily be removed and replaced for an inspection. From a single array position, ultrasonic guided waves propagate under the coating, down the length of the pipe and return information about potential defects. Focusing the ultrasonic energy at a predetermined location along the length of the pipe enhances the ability to detect defects that current state of the art inspection systems cannot. Focusing is achieved by applying excitation time delays to a multi-channel signal generation system. The excitation sources are equally spaced about the circumference of the pipe. Time delays are calculated using theoretically generated angular displacement profiles in a hollow cylinder. These theoretical displacement profiles are dependent upon excitation source influences. In this paper, the excitation source influence on focusing potential in pipe was studied. Further, focusing potential contour plots for different frequencies and distances from the excitation source were created. Based on the contour plots, sample focusing experiments were carried out.

The Characterization of Guided Waves on Hollow Cylinder From Non-Axisymmetric End Loading

2005 ◽  
Author(s):  
Longtao Li ◽  
Cunfu He ◽  
Bin Wu ◽  
Ying Li ◽  
Xiuyan Wang
Keyword(s):  
Hollow Cylinder ◽  
Cross Section ◽  
Guided Waves ◽  
Axial Direction ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Steel Pipe ◽  
Rapid Testing ◽  
Middle Point

Ultrasonic guided waves are used for the rapid testing of a steel pipe (O.D 70 mm, I.D 63 mm, 2544 mm long). The non-axisymmetric transducer ring (arc) is put on one end of the pipe to excite and receive the guided wave in the pipe. An artificial hole of 1 mm diameter can not be found by conventional axisymmetric end loading transducer. However, the non-axisymmetric transducer ring (arc), compared with the axisymmetric transducer ring, is very sensitive to the artificial hole when The middle point (MP) of the transducer arcs coincided with the center of the artificial hole on the cross section of the pipe. The results show that the non-axisymmetric end loading technology can locate the crack or defect on the pipe not only in the axial direction but also in the circumferential direction.

GUIDED WAVES IN A WATER LOADED HOLLOW CYLINDER

1996 ◽  
Vol 12 (5) ◽  
pp. 323-339 ◽  
Author(s):  
YOUNHO CHO ◽  
JOSEPH L. ROSE
Keyword(s):  
Hollow Cylinder ◽  
Guided Waves

The fractional Kelvin-Voigt model for circumferential guided waves in a viscoelastic FGM hollow cylinder

2021 ◽  
Vol 89 ◽  
pp. 299-313 ◽  
Author(s):  
Xiaoming Zhang ◽  
Zhi Li ◽  
Xianhui Wang ◽  
Jiangong Yu
Keyword(s):  
Hollow Cylinder ◽  
Guided Waves ◽  
Voigt Model
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