Experimental identification of stochastic loads using a nonlinear dynamical system coupled with an uncertain linear system

Anas Batou (1) , Christian Soize (1)

1 MSME - Laboratoire de Modélisation et Simulation Multi Echelle

The problem presented here concerns fuel assemblies for which the stochastic loads induced by turbulent fluid forces have to be identified. The simplified model used for this identification is composed of two coupled subsystems:(1) A nonlinear subsystem which is accurate and contains the quantity of interest (2) A linear subsystem which is less accurate and contains model uncertainties which have to be taken into account. Others sources of uncertainties are to be taken into account in the stochastic loads identification process: uncertainties concerning the stochastic loads and measurements errors. The identification is carried out using the moments method and the maximum likelihood method. Finally, the stochastic simplified computational model on which the identified stochastic loads are applied is used to construct statistics of the fretting wear of the fuel rods.

Mots clés: uncertainty quantification; nonlinear dynamics; modeling errors; model uncertainties; statistical inverse problem; identification of dynamycal systems; random matrix; uncertain dynamic loading

Domaines: Mécanique [physics.med-ph]; Probabilités [math.PR]; Statistiques [math.ST]; Vibrations [physics.class-ph]

Anas Batou, Christian Soize. Experimental identification of stochastic loads using a nonlinear dynamical system coupled with an uncertain linear system. Coupled problems 2009, International Conference on Computational Methods for Coupled Problems in Science and Engineering, CIMNE, Jun 2009, Ischia Island, Italy, Italy. pp.1-6. ⟨hal-00692163⟩