Rotor-structure interaction : theoretical-experimental model / Interação roto-estrutura : modelo teorico-experimetal

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

This work investigates the effects of the support structure and the hydrodynamic bearings on the dynamic behaviour of rotating machinery. The support structure, also known as foundation, was analysed experimentally and its modal parameters determined through the modal analysis of its frequency response functions (FRF). These parameters were refined through two optimization methods, the first one based on the Golden Search, and the other one on the Nonlinear Least Squares method. The modal model of the foundation was integrated to the rotorbearings system through the Mixed Coordinates method for the calculation of the unbalance response of the complete system. The complex modal analysis of the rotor-bearings-foundation system was applied to calculate the directional frequency response function (dFRF), and determine the effects of the tested parameters on the forward and backward modes. Two different aproaches were adopted to model hydrodynamic bearings: the finite difference method and an analytical solution using the short bearing theory. The finite difference method was employed to calculate the stiffness and damping coefficients of a finite journal bearing, and they were applied in the calculation of unbalance response and dFRF of the rotor. The analytical solution was used to calculate the harmonic response of the rotor and demontrate the bearing nonlinear behaviour. The results of the simulations were verified through experimental tests in laboratory

ASSUNTO(S)

metodo dos elementos finitos rotores hydrodinamic bearing fundações (engenharia) modal analysis finite element analysis analise modal foundations structure rotordynamics

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