Proposal of a theoretical-experimental model for rotor-bearing-structure interaction

Abstract

The study of rotating machines arouses the interest of many researchers in the field of machines and structures in view of the significant amount of typical phenomena that occur during their operation. This type of rotating system represents the largest and most important class of machinery, used in many different areas of mechanical engineering. In this context, obtaining a robust and efficient model for the analysis of rotating machines, especially in relation to the interface components between fixed and mobile parts, as the foundation structures and the hydrodynamic bearings, are the focus of this research project. The foundation structure will be analyzed experimentally, and through the modal analysis of the frequency response functions (FRF) it will be calculated its modal parameters. These parameters will be refined through optimization methods, since the techniques of modal analysis are susceptible to noise generated in the experimental measurements of the structure. The modal model of the foundation will be integrated to the rotor-bearing system through the mixed coordinates method, for the calculation of the complete system response. With respect to the hydrodynamic bearings, a numerical approach will be used to calculate the nonlinear hydrodynamic forces, through the solution of the Reynolds Equation. The procedure for the numerical solution of the Reynolds Equation to be used in this project employs the Finite Volume Method (FVM). For the modeling of the rotor will be used the classic Finite Element Method. In the process of implementation and simulation of the models, it will be used the software FORTRAN® and MATLAB®, software's oriented to applications of computational mechanics and computer-aided engineering. The results obtained with the proposed model will be verified experimentally in a test rig. (AU)