International Journal for Numerical Methods in Engineering
We propose a projection‐based model order reduction procedure for a general class of parametric q... more We propose a projection‐based model order reduction procedure for a general class of parametric quasi‐static problems in nonlinear mechanics with internal variables. The methodology is integrated in the industrial finite element code codeaster. Model order reduction aims to lower the computational cost of engineering studies that involve the simulation to a costly high‐fidelity differential model for many different parameters, which correspond, for example to material properties or initial and boundary conditions. We develop an adaptive algorithm based on a POD‐Greedy strategy, and we develop an hyper‐reduction strategy based on an element‐wise empirical quadrature in order to speed up the assembly costs of the reduced‐order model by building an appropriate reduced mesh. We introduce a cost‐efficient error indicator which relies on the reconstruction of the stress field by a Gappy‐POD strategy. We present numerical results for a three‐dimensional elastoplastic system in order to ill...
It has been anticipated and recently observed that axial cracks can occur at keyway corners of gr... more It has been anticipated and recently observed that axial cracks can occur at keyway corners of graphite bricks in the UK Advanced Gas-cooled Reactors (AGR). The crack initiation is triggered by internal stress reversal during reactor operation and may potentially lead to brick more cracks through a mechanism known as Prompt Secondary Cracking (PSC). To assess the likelihood of this occurring, a method for modelling dynamic fracture, known as eXtended Finite Element Method with cohesive elements (XCZM), is used to analyse whole 3D component fragmentation. Within this work, XCZM is used to model primary crack interactions with a methane hole and secondary crack profiles in a 3D brick slice under external hoop stress loading.
Une methodologie est proposee pour introduire des lois cohesives non regulieres, c'est a dire... more Une methodologie est proposee pour introduire des lois cohesives non regulieres, c'est a dire dont la derivee est discontinue d'un regime de fonctionnement a l'autre, dans le formalisme des elements finis etendus (X-FEM). Nous mettons en evidence des problemes de discretisation de la variable interne, sur laquelle repose la determination du regime de fonctionnement, avec une formulation standard. Nous adaptons a X-FEM deux formulations a plusieurs champs de la litterature afin d'y remedier tout en gardant une implementation simple: une pour les elements lineaires, l'autre pour les quadratiques. La methode est illustree sur des calculs quasi-statiques faisant appel a des techniques de pilotage du chargement.
International Journal for Numerical Methods in Engineering
We propose a projection‐based model order reduction procedure for a general class of parametric q... more We propose a projection‐based model order reduction procedure for a general class of parametric quasi‐static problems in nonlinear mechanics with internal variables. The methodology is integrated in the industrial finite element code codeaster. Model order reduction aims to lower the computational cost of engineering studies that involve the simulation to a costly high‐fidelity differential model for many different parameters, which correspond, for example to material properties or initial and boundary conditions. We develop an adaptive algorithm based on a POD‐Greedy strategy, and we develop an hyper‐reduction strategy based on an element‐wise empirical quadrature in order to speed up the assembly costs of the reduced‐order model by building an appropriate reduced mesh. We introduce a cost‐efficient error indicator which relies on the reconstruction of the stress field by a Gappy‐POD strategy. We present numerical results for a three‐dimensional elastoplastic system in order to ill...
It has been anticipated and recently observed that axial cracks can occur at keyway corners of gr... more It has been anticipated and recently observed that axial cracks can occur at keyway corners of graphite bricks in the UK Advanced Gas-cooled Reactors (AGR). The crack initiation is triggered by internal stress reversal during reactor operation and may potentially lead to brick more cracks through a mechanism known as Prompt Secondary Cracking (PSC). To assess the likelihood of this occurring, a method for modelling dynamic fracture, known as eXtended Finite Element Method with cohesive elements (XCZM), is used to analyse whole 3D component fragmentation. Within this work, XCZM is used to model primary crack interactions with a methane hole and secondary crack profiles in a 3D brick slice under external hoop stress loading.
Une methodologie est proposee pour introduire des lois cohesives non regulieres, c'est a dire... more Une methodologie est proposee pour introduire des lois cohesives non regulieres, c'est a dire dont la derivee est discontinue d'un regime de fonctionnement a l'autre, dans le formalisme des elements finis etendus (X-FEM). Nous mettons en evidence des problemes de discretisation de la variable interne, sur laquelle repose la determination du regime de fonctionnement, avec une formulation standard. Nous adaptons a X-FEM deux formulations a plusieurs champs de la litterature afin d'y remedier tout en gardant une implementation simple: une pour les elements lineaires, l'autre pour les quadratiques. La methode est illustree sur des calculs quasi-statiques faisant appel a des techniques de pilotage du chargement.
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Papers by Guilhem Ferte