Title
Elastic-wave identification of penetrable obstacles using shape-material sensitivity framework
Abstract
This study deals with elastic-wave identification of discrete heterogeneities (inclusions) in an otherwise homogeneous ''reference'' solid from limited-aperture waveform measurements taken on its surface. On adopting the boundary integral equation (BIE) framework for elastodynamic scattering, the inverse query is cast as a minimization problem involving experimental observations and their simulations for a trial inclusion that is defined through its boundary, elastic moduli, and mass density. For an optimal performance of the gradient-based search methods suited to solve the problem, explicit expressions for the shape (i.e. boundary) and material sensitivities of the misfit functional are obtained via the adjoint field approach and direct differentiation of the governing BIEs. Making use of the message-passing interface, the proposed sensitivity formulas are implemented in a data-parallel code and integrated into a nonlinear optimization framework based on the direct BIE method and an augmented Lagrangian whose inequality constraints are employed to avoid solving forward scattering problems for physically inadmissible (or overly distorted) trial inclusion configurations. Numerical results for the reconstruction of an ellipsoidal defect in a semi-infinite solid show the effectiveness of the proposed shape-material sensitivity formulation, which constitutes an essential computational component of the defect identification algorithm.
Year
DOI
Venue
2009
10.1016/j.jcp.2008.09.009
J. Comput. Physics
Keywords
Field
DocType
elastodynamics,constrained optimization,material sensitivity,identification,boundary integral equation,elastic-wave identification,shape-material sensitivity framework,direct bie method,elastodynamic scattering,shape-material sensitivity,ellipsoidal defect,defect identification algorithm,shape-material sensitivity elastodynamics identification inclusion boundary element method constrained optimization,minimization problem,nonlinear optimization framework,penetrable obstacle,inclusion,boundary element method,direct differentiation,nonlinear optimization,elastic moduli,augmented lagrangian,message passing interface
Inverse,Mathematical optimization,Ellipsoid,Mathematical analysis,Nonlinear programming,Waveform,Augmented Lagrangian method,Boundary element method,Mathematics,Inverse scattering problem,Constrained optimization
Journal
Volume
Issue
ISSN
228
2
Journal of Computational Physics
Citations 
PageRank 
References 
1
0.42
5
Authors
2
Name
Order
Citations
PageRank
Marc Bonnet132.65
Bojan B. Guzina211.43