Development of efficient rotordynamical models to study coupled lateral-torsional vibrations

In this thesis an accurate, efficient and fully coupled model for the evaluation of the dynamical behaviour of complex multi-rotor systems is presented. The model has been conceived with the purpose of modelling complex rotors through a systematic and practical approach and with the goal of investigating the bending-torsional interaction in rotor vibrations. The model is based on a finite element rotordynamics formulation and it is able to deal with long rotors characterised by complex topology, such as rotor with distributed inertias or complex connections. This kind of rotor and the way in which they are modelled may deeply influence the predicted dynamics of the system with particular concern to the lateral-torsional vibrations coupling. Thus, through the developed model, complicated shaft-to-rotor connections or particular mounted parts, otherwise not representable with classical models, may be mathematically described. The proposed model represents a systematic and practical approach to the rotor dynamics modeling issue and its main contribution to the research topic of coupled lateral-torsional vibration in rotors is due to its general topology