Nonlinear vibrations of a beam with non-ideal boundary conditions and subjected to two correlated or uncorrelated broadband random excitations - experiments, modeling and simulations

International audience; This study presents experiments and numerical simulations of a beam with non-ideal boundary conditions and subjected to two broadband correlated or uncorrelated random excitations. Modeling of a beam with non-ideal boundary conditions and additional static pretension, as well as the modeling of multipoint correlated or uncorrelated random excitations, are developed. Based on numerical simulations via an extension of the Harmonic Balance Method, comparisons between experiments and numerical simulations are performed for various broadband bi-point correlated random excitations. In order to achieve such an objective, experiments are performed for four types of correlation between the two broadband random excitations: correlated excitations in phase, opposite phase and quadrature phase, and uncorrelated excitations. Experimental results demonstrate that the different configurations of broadband random excitations drastically affect, not only the amplification or attenuation of some symmetric or antisymmetric modes of the beam in the vicinity of their primary resonance, but also the appearance of harmonics and a combination of harmonic components. Good correlations are observed between experiments and numerical simulations, thus validating the proposed modeling and the computational strategy for the prediction of the nonlinear vibrational phenomena of the beam system subjected to two correlated or uncorrelated broadband random excitations. To be noted that the experimental data set including the input and output measurements of the four configurations are provided as supplementary files on Talik et al. [1].