Workable mode optimization design method for dual-rotor system with inter-shaft bearing

In order to solve the problem that the dual-rotor system of aero-engine cannot avoid the critical speed， a model of dual-rotor system with inter-shaft bearing was established. Considering the influence of unbalance sensitivity，damper effect and the load effect of inter-shaft bearing，the tolerability evaluation functions of low-pressure and high-pressure rotor excited modes were constructed， the tolerability objective function and the constraint condition for optimization design on workable mode of dual-rotor were confirmed， and the optimization design method for the workable mode of dual-rotor system with inter-shaft bearing was established. It was found that compared with the traditional critical speed margin design criterion，the maximum amplitude of the disk of the dual-rotor system with inter-shaft bearing was reduced by 39.83%，the total mass of the shafting was reduced by 2.32%，and the external force of the fulcrum was reduced by 64.98% by using the optimization design method for the workable mode， indicating that the optimization design method for the workable mode of dual-rotor system with inter-shaft bearing was effective. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.