Development of numerical simulation method for nonlinear elastodynamic : application to acoustic imaging of defect with the help of cavity chaotic transducer

Abstract : In this thesis we propose the development of an innovative micro-damage imaging system based on a combination of Nonlinear Elastic Wave Spectroscopy techniques and “chaotic cavity transducer” concept. It consists of a combination of a PZT ceramic glued to a cavity of chaotic shape with the time reversal principle. The feasibility and capabilities of these new ideas is explored by numerical simulations, and optimal operational parameters for experimental implementation are suggested based on the modelling support. A large part of the research work conducted in this thesis is concentrated on the development of numerical simulation tools to help the improvement of such nonlinear imaging methods. A nodal Discontinuous Galerkin Finite Element Method (DG-FEM) scheme is extended to nonlinear elasto-dynamic including source terms. A Perfectly Matched Layer absorbing boundary condition well adapted to the DG-FEM scheme, called Nearly Perfectly Matched Layer (NPML), is also developed. In the case of orthotropic material as stability problems appear, a mixture of NPML and sponge layer, with a controllable ratio of these two kinds of absorbing layers, is introduced. The experimental validation of “chaotic cavity transducer” to focalize in reverberant and non-reverberant solid media with only one source is made. Classical time reversal, inverse filter and 1 Bit time reversal process are discussed and compared. The experimental demonstration of the use of a “chaotic cavity transducer”, in combination with the pulse inversion and 1-bit methods, to obtain an image of localized nonlinearity is made. This opens the possibility for high resolution imaging of nonlinear defects
Document type :
Theses
Other. Ecole Centrale de Lille, 2009. English. <NNT : 2009ECLI0014>


https://tel.archives-ouvertes.fr/tel-00578755
Contributor : Abes Star <>
Submitted on : Tuesday, March 22, 2011 - 10:09:08 AM
Last modification on : Friday, April 3, 2015 - 2:18:35 AM

File

Li_YiFeng_DLE.pdf
fileSource_public_star

Identifiers

  • HAL Id : tel-00578755, version 1

Collections

Citation

Yifeng Li. Development of numerical simulation method for nonlinear elastodynamic : application to acoustic imaging of defect with the help of cavity chaotic transducer. Other. Ecole Centrale de Lille, 2009. English. <NNT : 2009ECLI0014>. <tel-00578755>

Export

Share

Metrics

Consultation de
la notice

447

Téléchargement du document

236