Development and validation of a model to describe the bearings interaction in rotating machines due to elastic supporting structures

Abstract

This work focuses on the effects of the flexible supporting structures and on the bearing interaction caused by their elastic deflection on the whole rotorsubstructures system [1]. More particularly, a careful theoretical and experimental analysis is performed to understand how the supporting structures influence the rotors behaviour [2, 3] through the actions of the machine bearings. To this end, this study considers a model of the whole rotating machine [4], taking into account the coupling of the dynamic behaviour of the different system components. The whole FEM model has been implemented in the ANSYS [5] simulation environment. The main goal of this research, is to offer an optimal balance between efficiency and accuracy allowing the modelling of the real physical complex system and simultaneously the reduction of calculation times. The whole analysis has been developed and validated in cooperation with General Electric S.p.A. which provided the technical and experimental data related to some tests recently performed in Massa- Carrara (Italy) on a benchmark turbocompressor machine.