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Noninvasive multilevel geometric regularization of mesh‐based three‐dimensional shape measurement
Author(s) -
Colantonio G.,
Chapelier M.,
Bouclier R.,
Passieux J.C.,
Marenić E.
Publication year - 2020
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.6291
Subject(s) - finite element method , isogeometric analysis , computer science , initialization , regularization (linguistics) , spline (mechanical) , algorithm , subspace topology , cad , isotropy , polygon mesh , mathematics , mathematical optimization , geometry , artificial intelligence , structural engineering , engineering drawing , engineering , physics , quantum mechanics , programming language
Summary Finite element stereo digital image correlation (FE‐SDIC) requires a crucialcalibration phase in which the initial CAD needs to be updated to fit the actual shape of the specimen. On the one hand, the use of a FE mesh facilitates the coupling of measurements with simulation tools, while on the other hand, it provides a unique, fine description of both the geometry and the displacement, which often makes the shape measurement problem highly ill‐posed. As a remedy, we propose a hybrid isogeometric‐FE strategy that can measure a shape in terms of spline functions while considering as an input and output the analysis‐suitable FE mesh. Making use of the appealing spline refinement procedures and of Bézier‐based operators, multilevel smooth spline discretizations are built concurrently with the initial FE subspace and related to the multiscale images used for the initialization of the shape measurement. It results in a geometrically sound regularization which provides a spline parametrization of the optimal shape along with its FE twin. A noninvasive implementation from an existing FE‐SDIC code is also detailed. The performance of the proposed method is assessed on real images and comparisons are made with other published techniques to prove its efficiency.