Abstract: Aiming at the stiffness characteristics of the elastic ring support structure used in the aero-engine rotor system， the dynamic stiffness analysis and experimental tests as well as the analysis of its influence on the natural characteristics of the rotor system are carried out. First， a finite element model of the elastic ring support structure is established to calculate its dynamic stiffness， then the dynamic stiffness testing and verification is conducted. The experimental test results are basically consistent with the simulation results， which verify the correctness of the finite element analysis method of the elastic ring structure. Then， a finite element model is built which includes the rotor system and the elastic ring structure. Besides， the influence of the rotor system on the critical speed under the conditions of static and dynamic stiffness is studied. The results show that the dynamic stiffness of the elastic ring support structure has a significant impact on the critical speed. The first-order critical speed is reduced by 26%， and a new resonance frequency is generated. Therefore， the dynamic stiffness of the support structure should be fully considered when analyzing the natural characteristics of the rotor system.

Key words: elastic ring support structure; dynamic stiffness; finite element simulation; rotor system; critical speed