Reduced-order model for nonlinear dynamical structures having numerous local elastic modes in the low-frequency range

Anas Batou (1) , Christian Soize (1) , N. Brie (2)

1 MSME - Laboratoire de Modélisation et Simulation Multi Echelle
2 EDF R&D - EDF R&D

This research is devoted to the construction of a reduced-order computational model for nonlinear dynamical structures which are characterized by the presence of numerous local elastic modes in the low-frequency band. Therefore these structures have a high modal density in the low-frequency band and the use of the classical modal analysis method is not suited here. We propose to construct a reduced-order computational model using a small-dimension basis of a space of global displacements, which is constructed a priori by solving an unusual eigenvalue problem. Then the reduced-order computational model allows the nonlinear dynamical response to be predicted with a good accuracy on the stiff part of the structure. Themethodology is applied to a complex industrial structure which is made up of a row of seven fuel assemblies with possibility of collisions between grids and which is submitted to a seismic loading.

Mots clés: Reduced-order model; nonlinear dynamical structures; local elastic modes; low-frequency range

Domaines: Mécanique [physics.med-ph]; Vibrations [physics.class-ph]

Anas Batou, Christian Soize, N. Brie. Reduced-order model for nonlinear dynamical structures having numerous local elastic modes in the low-frequency range. International Conference on Noise and Vibration Engineering ( ISMA 2012), Katholieke Universiteit Leuven, Sep 2012, Leuven, Belgium. pp.3417-3426. ⟨hal-00734174⟩