Complex response of a rotor-bearings-foundation system / Resposta complexa de um sistema rotor-mancais-fundação

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

A rotating system, as it spins, can perform a whirling at the same direction (forward whirl) or at the opposite direction (backward whirl). These two whirling modes can define the rotor s vibration behavior. The directional formulation is used in modal analysis to represent the whirling modes, so it can be possible to obtain the forward and backward response separately on the frequency domain. The backward mode, that may occur as a result of the system s anisotropy, must be avoided, since it generates constant variations of the traction and compression tensions at the shaft, which can provoke fatigue failure. The objective of this work is to analyze the influence of the anisotropy degree of the bearings and supporting structure on the backward mode of whirl. Different rotor-bearings configuration where modeled and studied, using directional coordinates, for different bearings coefficients. Rigid and flexible shaft models where used, including a finite elements model. For a better understanding of the system s response, different experimental supporting structure (foundation) models where incorporated to the rotor-bearings system, and the directional response of the rotor-bearings-foundation system was calculated. The main foundation modes were represented by modal coordinates, and the resulting system is, thus, represented by mixed coordinates (physical coordinates for the rotor and modal coordinates for the foundation)

ASSUNTO(S)

foundations fundações (engenharia) bearing mancais finite element method rotordynamics rotores - dinamica metodos de elementos finitos

ACESSO AO ARTIGO

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