A FEM-based topological sensitivity approach for fast qualitative identification of buried cavities from elastodynamic overdetermined boundary data

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:47

Article

Bellis, Cedric^1,2  Bonnet, Marc¹ 

[1] Ecole Polytech, Solid Mech Lab UMR CNRS 7649, Dept Mech, F-91128 Palaiseau, France

[2] Univ Minnesota, Dept Civil Engn, Minneapolis, MN 55455 USA

关键词: Inverse scattering;    Time domain topological sensitivity;    Adjoint solution method;    Elastodynamics;    Finite element method;   

DOI  :  10.1016/j.ijsolstr.2010.01.011

来源: Elsevier

【 摘 要 】

A time-domain topological sensitivity (TS) approach is developed for elastic-wave imaging of media of arbitrary geometry. The TS, which quantifies the sensitivity of the misfit cost functional to the creation at a specified location of an infinitesimal hole, is expressed in terms of the time convolution of the free field and a supplementary adjoint field as a function of that specified location. Following previous studies performed under (mostly) static or time-harmonic conditions, the TS field is here considered as a natural and computationally efficient approach for defining a defect indicator function. This study emphasizes the implementation and exploitation of TS fields using standard displacement-based FEM approaches, a straightforward task once the correct sensitivity formulation is available. A comprehensive set of numerical experiments on 3D and 2D elastodynamic and acoustic configurations is reported, allowing to assess and highlight many features of the proposed TS-based fast qualitative identification such as its ability to identify multiple defects and its robustness against data noise. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

Free