Stephan C.,ONERA |
Festjens H.,SUPMECA Saint Ouen |
Renaud F.,SUPMECA Saint Ouen |
Dion J.-L.,SUPMECA Saint Ouen
Mechanical Systems and Signal Processing | Year: 2015
This paper describes a method for the identification and the tracking of poles of a weakly nonlinear structure from its free responses. This method is based on a model of multichannel damped sines whose parameters evolve over time. Their variations are approximated in discrete time by a nonlinear state space model. States are estimated by an iterative process which couples a two-pass Bayesian smoother with an Expectation-Maximization (EM) algorithm. The method is applied on numerical and experimental cases. As a result, accurate frequency and damping estimates are obtained as a function of amplitude. © 2015 Elsevier Ltd.