Passive control of tubes by cross correlation of ambient noise fields ∗
Sonia DJILI
1, Emmanuel MOULIN
2, Jamal ASSAAD
2, Fouad BOUBENIDER
3, Farouk BENMEDDOUR
21
Scientific and Technical Center of Research on Welding and Control, BP 64, route de Daly Brahim. Ch´ eraga, 16000 Algies. Algeria.
2
IEMN, OAE Department, CNRS UMR 8520, University of Valenciennes and Hainaut Cambr´ esis, Le Mont Houy 59313 Valenciennes Cedex 9. France.
3
Laboratory of physics of materials, University of sciences and technology Houari Boumedienne B.P. 32 El Allia- Bab Ezzouar, 16111 Algiers. Algeria.
Abstract
The tube or pipeline are used for the routing of the fluids such as gas, oil or water. The tubes deteriorate during its life. This dete- rioration can reveal defects, from where need for controlling of such structure. It is interesting to be able to detect damages in tubes by using a passive control method. The goal of this work is to show in experiments the possibility of using the function of cross correlation, between tow signals of noise, in order to make a passive control of the tubular structures. The noise in the tube was generated by flow of fluid.
The reproducibility of the function of cross correlation and its sensi- tivity to the presence of a defect, were checked for several frequencies in the frequently band of [200 Hz, 35kHz]. Moreover, the movement of the fluid in the tube generates a temperature variation; the influ- ence of this temperature variation on the cross correlation function was studied.
Keyword: Green function ambiant noise cross corrlation tube flow fluide.
∗IEEE ultrasonics symposium 2012
