Optimization of Hemispherical Shell Resonator Structure Based on Thermoelastic Dissipation

This paper reports a method to optimize the structure of a hemispherical shell resonator by reducing the thermoelastic dissipation. In accordance with the thermoelastic damping theory, we set up a thermal insulation structure to change the heat conduction distance to improve the thermoelastic quality factor. And according to the distribution of elastic strain energy on the resonator, we set up the thermal insulating cavities and thermal insulating layers at the top and rim of the resonator to change the heat conduction distance, respectively. The vibration characteristics of the four new resonators are compared with the conventional resonator by finite element calculation, and the new structural resonators are fabricated with the optimal parameter. We measured that the quality factor ( $Q$ -factor) of the optimized resonator was improved by 13.8 times than that of the original structural resonator. It is also found that by adjusting the insulation structure, not only the thermoelastic quality factor of the resonator can be improved, but also the modal frequency of the resonator can be adjusted, which is able to realize the fine control of the vibration characteristics of the resonator. [2023-0168]