Structure similitude for a nonlinear rotor system with connected Geislinger coupling

This investigation is aimed to propose scaling laws for a nonlinear system with connected Geislinger coupling. Different from the scaling laws for rotor systems with linear stiffness that are commonly used, the proposed method has better prediction accuracy for a rotor system with two rotor connected by nonlinear coupling. First, a crankshaft-Geislinger coupling-propeller shaft model is established. On this basis, frequency responses and critical velocities between nonlinear and linear prototype models are compared. Then, the nonlinear stiffness factor is derived based on the system vibration equation and nonlinear stiffness characteristics, and the scaling laws are carried out. Finally, the prediction accuracy is calculated with different scaled models in terms of the modal, frequency response, and transient response respectively. The result shows a better similarity and prediction using the proposed method, which will be powerful in systems with nonlinear stiffness like large flexible structures or nonlinear connections.