Time reversal of ultrasonic waves in solids: Theory and experiments

1995 ◽  
Vol 98 (5) ◽  
pp. 2875-2875 ◽  
Author(s):  
Carsten Draeger ◽  
Didier Cassereau ◽  
Mathias Fink
Keyword(s):  
Time Reversal ◽  
Ultrasonic Waves ◽  
Theory And Experiments

scholarly journals INFLUENCE OF NOISE ON SUBWAVELENGTH IMAGING OF TWO CLOSE SCATTERERS USING TIME REVERSAL METHOD: THEORY AND EXPERIMENTS

2009 ◽  
Vol 98 ◽  
pp. 333-358 ◽  
Author(s):  
Matthieu Davy ◽  
Jean-Gabriel Minonzio ◽  
Julien de Rosny ◽  
Claire Prada ◽  
Mathias Fink
Keyword(s):  
Time Reversal ◽  
Subwavelength Imaging ◽  
Influence Of Noise ◽  
Theory And Experiments

Time Reversal Technique for Ultrasonic Guided Wave Inspection

2006 ◽  
Vol 321-323 ◽  
pp. 776-779
Author(s):  
Hak Joon Kim ◽  
Sung Jin Song ◽  
Jung Ho Seo ◽  
Jae Hee Kim ◽  
Heung Seop Eom
Keyword(s):  
Time Delay ◽  
Power Plant ◽  
Time Reversal ◽  
Nuclear Power ◽  
Guided Waves ◽  
Performance Enhancement ◽  
Guided Wave ◽  
Ultrasonic Waves ◽  
Ultrasonic Guided Waves ◽  
Ultrasonic Guided Wave

For the long range inspection of structures in nuclear power plant using array transducers, it is necessary to focus waves on defects under interrogation. To take care of such a need, in this study we adopt a time reversal technique that is claimed to be very robust to focus ultrasonic waves on defects. Specifically, we calculate the appropriate time delay using the time reversal technique and re-generate ultrasonic guided waves that are focusing to an interrogated defect with the calculated time delay. In this paper, we describe the principle of the time reversal technique briefly and present the performance enhancement obtained by the time reversal techniques.

scholarly journals Damage Detection of Closed Crack in a Metallic Plate Using Nonlinear Ultrasonic Time Reversal Method

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Wang Zhang ◽  
Weiliang Wu ◽  
Xiaoyi Sun ◽  
Li Xiao ◽  
Wenzhong Qu
Keyword(s):  
Time Reversal ◽  
Damage Index ◽  
Ultrasonic Waves ◽  
Closed Crack ◽  
Time Reversibility ◽  
Imaging Algorithm ◽  
Reconstructed Signal ◽  
Ultrasonic Time ◽  
Nonlinear Ultrasonic ◽  
Nonlinear Components

Initial cracks in metallic structures incline to be closed at rest. Such incipient damage generally fails to be detected and located with traditional linear ultrasonic techniques because ultrasonic waves penetrate the contact area of the closed crack. In this paper, an imaging algorithm based on nonlinear ultrasonic time reversal method is proposed to detect closed cracks in aluminum plates. Two surface-bonded piezoelectric transducer arrays are used to generate, receive, and reemit ultrasonic wave signals. The closed crack is simulated by tightening a bolt on the aluminum plate. By applying large amplitude excitation voltage on the PZT transducers, the closed crack could be opened and closed. The transmitted waves recorded by PZT array contain nonlinear components, the signals are time reversed and emitted back, and the tone burst reconstructions are achieved. The linear reciprocity and the time reversibility break down due to the presence of the nonlinear components. The correlation coefficient between the original excitation signal and the reconstructed signal is calculated to define the damage index for individual sensing path and is used to develop an imaging algorithm to locate the closed crack on the plate. The experimental results demonstrate that incident wave signals and their reconstructed signals can be used to accurately detect and locate closed cracks.

Time Reversal Focusing Applied to Lithotripsy

1996 ◽  
Vol 18 (2) ◽  
pp. 106-121 ◽  
Author(s):  
Jean-Louis Thomas ◽  
François Wu ◽  
Mathias Fink
Keyword(s):  
Time Reversal ◽  
Surrounding Medium ◽  
Ultrasonic Field ◽  
Ultrasonic Waves ◽  
Least Mean Square ◽  
Transducer Arrays ◽  
Sharp Focusing ◽  
Spatial Coordinates ◽  
Pulsed Ultrasonic ◽  
Focal Zone

Time reversal of ultrasonic field allows a very efficient approach to focusing pulsed ultrasonic waves through lossless inhomogeneous media. Time reversal mirrors (TRM) are made of large transducer arrays, allowing the incident acoustic field to be sampled, time reversed and re-emitted. Time reversal processing permits a choice of any temporal window to be time reversed, allowing operation in an iterative mode. In multitarget media, this process converges on the most reflective target, i.e., the dominant scatterer. In this paper, the time reversal process is applied to track, in real time, a moving gall bladder or kidney stone embedded in its surrounding medium. We investigate the feasibility of a piezoelectric shock wave generator in which the focal zone is moved electronically to track the stone during a lithotripsy treatment. We show that TRM allows us to obtain sharp focusing on one bright point of the stone. The time of flight profile is then determined and used in a least-mean-square method to calculate the spatial coordinates of the stone.

Green Functions for Cylindrical Elastic Waves in Aluminum: Comparison Between Theory and Experiments

1994 ◽  
Vol 61 (1) ◽  
pp. 219-221 ◽  
Author(s):  
A. Mourad ◽  
B. Castagne`de ◽  
E. Mottay
Keyword(s):  
Elastic Waves ◽  
Tangential Force ◽  
Ultrasonic Waves ◽  
Displacement Fields ◽  
Numerical Predictions ◽  
Elastic Thin Plate ◽  
Experimental Works ◽  
Laser Interferometric ◽  
Force Problem ◽  
Theory And Experiments

A comparison between experimental and theoretical displacement fields for the tangential force problem (which is a model of the thermoelastic regime for laser generated ultrasound) at an aluminum interface is reported. The numerical predictions are based on a standard formulation of the transient generation of elastic waves along a line source. In the configuration of a purely elastic thin plate, the cylindrical elastic waves are then detected on the other side by a point-like receiver. The experimental works is carried out with a pulsed Nd:YAG laser for the generation and a laser interferometric probe for the detection of ultrasonic waves.

Reflection and time-reversal of ultrasonic waves in the vicinity of the Rayleigh angle at a fluid-solid interface

2005 ◽  
Vol 118 (5) ◽  
pp. 3145-3153 ◽  
Author(s):  
François Vignon ◽  
Fabrice Marquet ◽  
Didier Cassereau ◽  
Mathias Fink ◽  
Jean-François Aubry ◽  
...  
Keyword(s):  
Time Reversal ◽  
Ultrasonic Waves ◽  
Solid Interface ◽  
Rayleigh Angle

"Escherichia coli-milk" Biofilm Removal from Stainless Steel Surfaces: Synergism between Ultrasonic Waves and Enzymes

Biofouling ◽  
2003 ◽  
Vol 19 (3) ◽  
pp. 159-168 ◽  
Author(s):  
Nadia Oulahal- Lagsir ◽  
Adele Martial- Gros ◽  
Marc Bonneauc ◽  
Loic Bluma
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Ultrasonic Waves ◽  
Biofilm Removal ◽  
Steel Surfaces

" Escherichia coli -milk" Biofilm Removal from Stainless Steel Surfaces: Synergism between Ultrasonic Waves and Enzymes

Biofouling ◽  
2003 ◽  
Vol 19 (3) ◽  
pp. 159-168 ◽  
Author(s):  
NADIA OULAHAL-LAGSIR ◽  
ADELE MARTIAL-GROS ◽  
MARC BONNEAU ◽  
LOIC BLUM
Keyword(s):  
Escherichia Coli ◽  
Stainless Steel ◽  
Ultrasonic Waves ◽  
Biofilm Removal ◽  
Steel Surfaces
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