Research on vibration characteristics of resonator for the HRG

Resonator is the core structure of hemispherical resonator gyro (HRG), and its vibration characteristics play an important role in the output accuracy of gyro. A method combining dynamics model and finite element method (FEM) is proposed to study vibration characteristics of resonator. Firstly, this paper established dynamics equations of ideal resonator and dynamics equations of resonator with density distributed nonuniformity, and gave the mathematical expression of frequency split. Then, accomplished modal analysis and obtained natural frequency, mode shapes of resonator based on ANSYS Workbench. Finally, established the resonator model in consideration of density distributed nonuniformity by FEM, and investigated the influnce of the 4^th harmonic of density nonuniformity on resonator's frequency split. The finite element analysis was in good agreement with the results calculated by dynamics equations, which verified the accuracy of dynamics model.