Análise do comportamento dinâmico de rotores embarcados em regimes não-lineares sob a influência de incertezas paramétricas

Abstract

he understanding of rotordynamics, as well as the ability to model and predict the physical behavior of these systems, has escalated rapidly in recent decades. The new applications aim to optimize performance and reduce costs, without reducing safety and comfort, which has forced rotating systems to the extreme. Therefore, this Doctoral Thesis presents a numerical and experimental tests on the non-linear behavior of rotating systems subjected to base excitations and under the influence of parametric uncertainties. A model that considers nonlinearities due to large displacements is obtained from the Lagrange equations and the Finite Element method, in order to allow vibrations due to the motion of the rotor base. Subsequently, the deterministic model was expanded to include bearings with stochastic stiffness. Numerical analysis investigated a rotating machine composed of a flexible shaft containing a hard disk supported by two bearings. A test bench was built and used to validate the model, allowing the comparison of the implemented mathematical model with the experimental measurements, where the rotor vibration responses were obtained in the time and frequency domains. The results obtained demonstrate the representativeness of the proposed model.