Energy flow uncertainties in vibrating systems: Definition of a statistical confidence factor

A method for evaluating the energy flow confidence level in vibrating systems with randomly perturbed parameters is presented. The energy flow is predicted in terms of the mobilities of resonant subsystems or by the solution of the velocity wave field for non-resonant subsystems. The statistical moments of the energy flow are calculated by a perturbation technique and a confidence factor is defined as the ratio between mean and standard deviation. The properties of the confidence factor are investigated by a theoretical analysis as a function of frequency. Three cases are studied to compare the confidence factor obtained theoretically with a prediction, provided by a Monte-Carlo simulation. (C) 2003 Elsevier Science Ltd. All rights reserved.