Study of thermoelastic damping in fully clamped bilayered rectangular microplate resonators based on three-dimensional heat conduction

Abstract

Under the condition that microresonators work at room temperature or vaccum, thermoelastic damping is one of the main mechanisms of energy dissipation. Thermoelastic damping caused by the internal consumption of thermoelastic materials has always prevented the improvement of the quality of microresonators. In this paper, the theoretical model of thermoelastic damping in fully clamped bilayered plate microresonators based on the theory of three-dimensional heat conduction is first established and then verified to be equivalent to the previous single-layer model or not through the formula derivation. Analysis on thermoelastic damping at the first-order frequency where microresonators usually work is carried out afterwards. The differences of thermoelastic damping in the present three-dimensional model with different materials are investigated, including the convergence speed and the value of thermoelastic damping with different thicknesses. Then, with different lengths, widths, and thicknesses, but the same combination of materials, the thermoelastic damping is investigated in the present model. Furthermore, the present bilayered model is compared with the single-layer model to investigate their equivalent relationship. Finally, the present three-dimensional model is compared with the one-dimensional model and FEM models to investigate its feasibility.