Abstract
Thermoelastic dissipation (TED) is a key intrinsic damping mechanism that constrains the performance and quality factor of micro- and nanoscale resonators, particularly when other loss sources are minimized. At nanometer scales, classical continuum mechanics and Fourier heat conduction become inadequate due to pronounced surface effects and nonclassical thermal transport. In this study, a size-sensitive analytical model is developed to evaluate TED in vibrating rectangular nanoplates by simultaneously incorporating surface theory for mechanical size dependence and the Moore-Gibson-Thompson (MGT) heat transfer model for generalized thermoelastic behavior. The governing equations of motion and heat conduction are derived within the framework of Kirchhoff plate theory, and the temperature field is obtained under the MGT formulation. By separating the real and imaginary parts of the complex frequency (CF) and employing the CF method, a compact single-term expression for TED is achieved. Model accuracy is verified through comparison with existing results, followed by a comprehensive parametric investigation of surface properties, plate geometry, boundary conditions, and material characteristics. The results demonstrate that surface effects and non-Fourier thermal behavior significantly influence TED in nanoscale plates, especially at small thicknesses and higher vibrational modes, underscoring the necessity of advanced size-dependent modeling for reliable nanoresonator design.