Studies on dynamic characteristics of the joint in the aero-engine rotor system

The joint as a major part of the aero-engine rotating shafts directly influences its rotordynamics and state stability. This paper studies the dynamic effects of structure parameters and the external load on the stiffness and contact state of the rotor joints with nonlinear finite-element method and experiments. And a sensitivity analysis of critical speeds and vibration modes with respect to typical parameters (stiffness of the spline joints) is performed with finite difference methods, through two approaches, i.e. relative sensitivity analysis and absolute sensitivity analysis. The study results show that the stiffness and contact state of joints vary with external loads and geometry structures, and affect the rotor system operating. It is advisable to consider the influence of the position, structural parameter and external load of the rotor joints on aero-engine structure dynamics design.

► The joints will affect the dynamics characteristic of rotors.
► The stiffness and the contact state of joints vary with different conditions.
► The stiffness of joints is mainly affected by the impact of the external load.
► The changes of the contact state influence the rotor imbalance response.