Dynamics of rotating non-linear thin-walled composite beams: analysis of modeling uncertainties

Abstract

In this article a non-linear model for dynamic analysis of rotating thin-walled compositebeams is introduced. The theory is deduced in the context of classic variationalprinciples and the finite element method is employed to discretize and furnish a numericalapproximation to the motion equations. The model considers shear flexibility as wellas non-linear inertial terms, Coriolis’ effects, among others. The clamping stiffness ofthe beam to the rotating hub is modeled through a set of spring factors. The modelserves as a mean deterministic basis to the studies of stochastic dynamics, which are theobjective of the present article. Uncertainties should be considered in order to improve thepredictability of a given modeling scheme. In a rotating structural system, uncertainties arepresent due to a number of facts, namely, loads, material properties, etc. In this study theuncertainties are incorporated in the beam-to-hub connection (i.e. the connection angleand the springs) and the rotating velocity. The probability density functions of the uncertainparameters are derived employing the Maximum Entropy Principle. Different numericalstudies are conducted to show the main characteristics of the uncertainty propagation inthe dynamics of rotating composite beams.Keywords: non-linear beams, dynamics, uncertainties, stochastic modeling, rotatingcomposite beams