Assessment of broadhand ultrasonic attenuation measurements in inhomogeneous media

Goueygou, Marc; Piwakowski, Bogdan; Ould Naffa, S.; Buyle-Bodin, François

Document type :

Article dans une revue scientifique

DOI :

10.1016/S0041-624X(02)00094-X

Title :

Assessment of broadhand ultrasonic attenuation measurements in inhomogeneous media

Author(s) :

Goueygou, Marc [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Piwakowski, Bogdan [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Ould Naffa, S. [Auteur]
Buyle-Bodin, François [Auteur]
Laboratoire de Mécanique de Lille - FRE 3723 [LML]

Journal title :

Ultrasonics

Pages :

77-82

Publisher :

Elsevier

Publication date :

2002

ISSN :

0041-624X

English keyword(s) :

Random media
Field simulation
Transducer coupling function
Concrete NDT
Attenuation measurement

English abstract : [en]

In this paper, we address the problem of evaluating the acoustic attenuation of “difficult” media, i.e. highly attenuating and scattering media. In a broadband, through transmission setup, the signals acquired from such ...
Show more >In this paper, we address the problem of evaluating the acoustic attenuation of “difficult” media, i.e. highly attenuating and scattering media. In a broadband, through transmission setup, the signals acquired from such media are characterized by a poor signal-to-noise ratio. Therefore, an accurate estimate of attenuation cannot be obtained from a single measurement, but multiple measurements must be combined. Two methods are considered to yield a single estimate of attenuation from multiple measurements. The first one, the “average attenuation” (AA) method, consists in a simple average of individual attenuation estimates. The second one, the “cross spectrum” (CS) method, is based on a system identification approach. In order to evaluate the estimation errors for these methods, ultrasonic signals transmitted through a material of known attenuation were simulated and mixed with both coherent and incoherent noise. In all tests performed, the “CS” method was found to yield the most accurate estimate. This method, combined time delay compensation, is then applied to real signals measured from a concrete slab. A valid frequency band for the attenuation estimate can be defined based on the coherence function. Results from this research are being applied to characterize the degradation of concrete structures using high-frequency ultrasound.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Non spécifiée

Popular science :

Non

Collections :