IDENTIFICATION OF A NONLINEAR BEAM THROUGH A STOCHASTIC MODEL BASED ON A DUFFING OSCILLATOR

This work proposes a model of a nonlinear beam-shaker as a Duffing oscillator. The modal parameters of the linear equivalent systems and the nonlinear stiffness are estimated by stochastic methods considering the restoring force surface method. The parameters probability density functions (PDFs) are estimated of nonparametric way and a stochastic model is obtained with confidence limits to the responses. The model is validated with new experimental data through Monte-Carlo simulations. The results have been shown the capability to describe the nonlinear behavior of the beam considering uncertainties quantification.