Skip to Main content Skip to Navigation
Theses

Analyse de structures vibrantes dotées de non-linéarités localisées à jeu à l'aide des modes non-linéaires

Abstract : This work is a collaboration between EDF R&D and the Laboratory of Mechanics and Acoustics. The objective is to develop theoretical and numerical tools to compute nonlinear normal modes (NNMs) of structures with localized nonlinearities. We use an approach combining the harmonic balance and the asymptotic numerical methods, known for its robustness principally for smooth systems. Regularization techniques are used to apply this approach for the study of nonsmooth problems. Moreover, several aspects of the method are improved to allow the computation of NNMs for systems with a high number of degrees of freedom (DOF). Finally, the method is implemented in Code_Aster, an open-source finite element solver developed by EDF R&D. The nonlinear normal modes of a two degrees-of-freedom system are studied and some original characteristics are observed. These observations are then used to develop a methodology for the study of systems with a high number of DOFs. The developed method is finally used to compute the NNMs for a model U-tube of a nuclear plant steam generator. The analysis of the NNMs reveals the presence of an interaction between an out-of-plane (low frequency) and an in-plane (high frequency) modes, a result also confirmed by the experiment. This modal interaction is not possible using linear modal analysis and confirms the interest of NNMs as a diagnostic tool in structural dynamics.
Complete list of metadatas

Cited literature [136 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00933366
Contributor : El Hadi Moussi <>
Submitted on : Monday, January 20, 2014 - 2:09:33 PM
Last modification on : Thursday, January 23, 2020 - 6:22:03 PM
Long-term archiving on: : Tuesday, April 22, 2014 - 12:10:12 PM

Identifiers

  • HAL Id : tel-00933366, version 1

Citation

El Hadi Moussi. Analyse de structures vibrantes dotées de non-linéarités localisées à jeu à l'aide des modes non-linéaires. Mécanique des structures [physics.class-ph]. Aix-Marseille Université, 2013. Français. ⟨tel-00933366⟩

Share

Metrics

Record views

825

Files downloads

4661