Towards cad models automatic simplification for finite element analysis

International audienceThe preparation of a finite element analysis (FEA) model from a computer aided design (CAD) model is still a difficult task since its boundary representation (B-Rep) is often composed of a large number of narrow faces and short edges that are much smaller than the desired element size (for mesh generation). Consequently, these faces and edges can be considered as geometric artefacts that are irrelevant for the meshing process. Such inconsistencies often cause poorly-shaped elements and meshes that are locally over-densified. These inconsistencies not only slow down the solver (using too many elements) but also produce poor simulation results. In this context, we proposed a "Mesh Constraint Topology" (MCT) model with adaptation operators aiming at transforming a CAD model into a FE model which only contains mesh-relevant faces edges and vertices, i.e. an explicit model of data intrinsic to the meshing process. This paper specifically presents a set of criteria that can be used in order to simplify a CAD model using MCT transformations i.e. edge deletion, vertex deletion, edge split, edge collapsing, vertices merging. The simplification criteria proposed in this paper can be classified using the three following categories: * geometric conformity to mesh generation issues * topological consistency * respect of boundary conditions Application and results are presented through the adaptation of a set of CAD models using these simplification criteria