Modelling methodology of MEMS structures based on Cosserat theory

Modelling MEMS involves a variety of software tools that deal with the analysis of complex geometrical structures and the assessment of various interactions among different energy domains and components. Moreover, the MEMS market is growing very fast, but surprisingly, there is a paucity of modelling and simulation methodology for precise performance verification of MEMS products in the nonlinear regime. For that reason, an efficient and rapid modelling approach is proposed that meets the linear and nonlinear dynamic behaviour of MEMS systems.Comment: Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/16838

Modelling ground vibrations induced by harmonic loads

A finite-element model combining the frequency domain thin-layer method with paraxial boundary conditions to simulate the semi-infinite extent of a soil medium is presented in this paper. The combined numerical model is used to deal with harmonic vibrations of surface rigid foundations on non-horizontal soil profiles. The model can deal with soil media over rigid bedrock or significant depths of half-space. Structured finite elements are used to mesh simple geometry soil domains, whereas unstructured triangular mesh grids are employed to deal with complex geometry problems. Dynamic responses of homogeneous as well as layered soil profiles are simulated and validated against analytical and approximate solutions. Finally, the model is used to deal with surface ground vibration reduction, in which it is first validated against published results and then followed by an example involving a bridge

Construction de la matrice de l'élément fini triangulaire à déformation constante pour l'étude des problèmes à potentiel à partir de critères de consistance

International audienceCe papier court démontre comment la matrice d'un élément fini triangulaire à trois nœuds peut être construite de façon très simple, pour l'étude des problèmes à potentiels, à partir des conditions de consistance de « mouvement de solide rigide » et de symétrie, sans aucune référence aux fonctions d'interpolation, aux conditions de compatibilité, ou toute autre méthodologie conventionnelle en éléments finis. Cette démarche démontre également que la matrice de l'élément triangulaire à trois nœuds est unique