A METHOD TO ANALYSE THE INTERACTION BETWEEN ROTOR-FOUNDATION SYSTEMS

摘要

This paper presents a methodology for the analysis of the foundation behaviour and its influence on the whole system (rotor-bearings-foundation), using a mathematical approach to determine its modal parameters such as modal mass, damping factor and natural frequency[1]. The analysis of the complete system is done applying the discretization of the foundation and rotor by finite element method. The analysis of the analytical transfer function of the model was obtained for a unit harmonic force exciting one node. The evaluation of the foundation modal parameters is done by the analysis of the structure frequency response function, obtained by Fourier Transform. The modes associated to the natural frequencies which significantly participate of the system response are chosen using the frequency spectrum. Afterwards, the mass, damping factor and stiffness of the considered modes are obtained, finally, the analysis of the complete system frequency response function is done and the analytical results are showed.