Non-intrusive implementation of IGA in industrial FEM codes

Abstract : Isogeometric analysis (IGA), introduced by Hughes et al. [1], intends to directly link the geometry of CAD with the analysis by using the same shape functions. IGA has proven its efficiency in a large amount of domains and has shown a per-degree of freedom accuracy and robustness superior to the standard Finite Element Method (FEM). However the development of IGA in industrial software still remains limited. Indeed, the global definition of the shape functions in an intermediate space (composed of several knot-span elements) questions the element-wise structure of standard FE software. In order to fill the gap between IGA and FEM from a numerical and implementation point of view, and following the existing link between these two methods [2, 3], we propose a global strategy to link IGA with an industrial FEM codes. From an initial NURBS definition of the geometry it is hence possible to find a corresponding FE description thanks to some global operators. The created FE mesh associated with its Lagrange shape functions is an input mesh for standard FE software. Following the projection steps back, a relation between the FE stiffness operator and the NURBS one can be found. The proposed technique was validated on linear cases in two-and three dimensions. As on illustration, Figure 1 shows results on a classical IGA elastic problem in 3D. The computation made in an industrial FE software using the proposed method gives results similar to IGA computation. Furthermore, the technique can be efficiently used in case of "non intrusive" coupling methods [4]. Indeed, a global NURBS geometry, which comes from the CAD and is never modified, can be easily coupled with a local FE geometry constructed through the IGA-FEM bridge. This allows local enrichment and can be very interesting when using complex or non linear local model for which competitive FE software already exist. All these different aspects will be discussed during the talk.
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Communication dans un congrès
6th European Conference on Computational Mechanics, Jun 2018, Glasgow, United Kingdom. pp.11 - 15
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https://hal.archives-ouvertes.fr/hal-01860396
Contributeur : Ludovic Chamoin <>
Soumis le : lundi 4 mars 2019 - 14:25:29
Dernière modification le : lundi 4 mars 2019 - 15:35:21

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  • HAL Id : hal-01860396, version 1

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Marie Tirvaudey, Robin Bouclier, Jean-Charles Passieux, Ludovic Chamoin. Non-intrusive implementation of IGA in industrial FEM codes. 6th European Conference on Computational Mechanics, Jun 2018, Glasgow, United Kingdom. pp.11 - 15. 〈hal-01860396〉

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