Thema: Ultrascchallfeld, Zeitumkehr
Autor/Institution: Chakroun, N.;Fink, M.;Wu, F.
/Univ. Paris VII, F
Title: Basic principles of ultrasonic time reversal processing in nondestructive
testing
Titel : Grundlagen des Ultraschall-Zeitumkehrprozesses in der zerstörungsfreie
Prüfung
Quelle : Review of Progress in Quantitative Nondestructive Evaluation. Proceedings
of the Twenty-First Symposium, Snowmass Village, USA, 31.7.-5.8.1994
13 14A
1995
; New York: Plenum Press
; ISBN 0-306-45062-3
; S.937-943
; 7S,7B,5Q
; TIB-RO141(14,1);BAM-Z-0923/95
; E
Abstract:
The experiments made with the Time Reversal Mirror prototype of 121
elements, with 330 mm radius of curvature and working at 5 MHz, allow to
detect small defects located beneath a complex geometry interface with a
high signal to noise. The time reversal process is a self adaptive
technique and all the acoustic energy of the system naturally focus on the
defect. The wavefront distortions induce by the direct propagation are
naturally compensate during the inverse one. C-SCAN acquisition allows to
make an accurate cartography of the sample on which a 0.4 mm diameter flat
bottom hole at 65 mm depth appears on a large zone and emerges from the
microstructure noise. On the contrary of a conventional technique, the
time reversal procedure automatically produces a focussed beam matched to
the defect shape and doesn't require an exact positionning of the 2-D
array above the flaw. These performances shows the potential of the time
reversal process which seems to be the most adapted technique to be used
for industrial problems. F33,B13,H13,A25
Database Keywords: Ultraschallprüfung, Schallausbreitung, :Schallfeld, Testfehler, C Bild,
Fehlerart
23 Wellengleichung, Zeitumkehr, :Flachbodenbohrung, :Inverses Problem,
Kompliziertgeformtes Objekt
24 Z:A
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Rolf Diederichs 1. Dec 1996,
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