Nonlocal Thermoelastic Damping in Nano-Electromechanical Beam Resonators

Thermo-elastic damping (TED) is a source of dissipation in micro/nano-scale resonators and recognized as a dominant loss mechanism at room temperature. Predicting TED is crucial in the design of high quality factor micro/nano-electromechanical systems (MEMS/NEMS) resonators. Experimental results revealed that the size effects are significant in the mechanical behavior of these structures when thedimensions become small and comparable to molecular distances. In this paper, the size-dependent TED of beam-resonators has been investigated on the basis of the nonlocal elasticity theory and Euler–Bernoulli beam theory. The governing equations of coupled thermoelastic problems have been derived for transverse vibration of a thin beam. The Galerkin discretization method and complex-frequency approach have been used to study eigenvalue solution of TED of a beam resonator with both ends clamped and isothermal. As a validation, the obtained results when the nonlocal effect is not taken into account have been compared with benchmark analytic results available in the literature for a silicon nano-beam resonator and a very good agreement has been observed. Finally, numerical results addressing the significance of the nonlocal effect on the TED ratio of the beam resonators have been presented

کلیدواژه ها:

Nonlocal elasticity theory ، Euler–Bernoulli beam theory ، Thermo-elastic damping ، Nano-beam ، Quality factor