Similarity Design and Behavior Prediction of Rotor Systems Subject to Non-uniform Preloads

In the study of rotor dynamics, it is of great theoretical and practical significance to design a scaled rotor system that can reflect the dynamic characteristics and behavior of the prototype accurately. However, modern rotor systems are usually assembled by bolted structures, the discontinuity and complexity of its structure bring difficulties to the similarity design of scaled rotors. In this regard, this paper proposes a similarity design method that can accurately predict the dynamic behavior of discontinuous rotor systems. First, the rotor structure is treated continuously using the equivalent material modeling theory. Then, based on the similarity theory, the scaling factors of key structural and physical parameters are obtained. Finally, two kinds of scaled rotor systems under different preload conditions with different sizes are designed. In addition, the first-two critical speeds of the prototype are predicted. The calculated results show that the maximum deviation of the rotor model with different reduced scale dimensions in predicting the critical speed of the prototype is less than 4.03%. The reduced scale rotor model obtained by using this similarity design method can accurately predict the dynamic behavior of the prototype. This method provides theoretical guidance and reference for the design of the reduced scale model of the discontinuous rotor system.