Mechanical models of influence of interface deformation on rotor dynamic characteristics

In order to analyze the problems of vibration increasing and interface wear of aero engine during work, the dynamic models of rotor-bearing system with three disks were established on the basis of the structural feature analysis. A parametric description has been made to analyze the coaxial and parallelism deviation of contact interface, and the dynamic differential equation for rigid high pressure rotor system was obtained by the Lagrangian method considering the interface deformation. The results exhibit that the interface deformation will cause the additional excitation force in the rigid rotor system, where the amplitude of the additional excitation force caused by the coaxial deviation is proportional to the square of the speed, and only applies to the corresponding degree of freedom; the amplitude of the additional excitation force caused by the parallelism deviation is only related with the rigidity and the deviation magnitude regardless of the speed, and it also applies to the support freedom.