Modeling size-dependent thermoelastic energy dissipation of graphene nanoresonators using nonlocal elasticity theory

Abstract

Recent developments in nanostructured materials have led to the use of graphene sheets as resonators in advanced micro- and nanoelectromechanical systems. An important feature of micro- and nanoresonators is their ability to function with low power dissipation. The main intrinsic mechanism of energy loss in these advanced devices is thermoelastic damping (TED). In this article, we study TED effects in orthotropic graphene sheets of varied lengths operating at different temperatures using nonlocal elasticity theory. For this purpose, the fundamental thermoelastic relations are used to develop a system of coupled partial differential equations to describe the behavior of graphene nanoresonators. The orthotropic mechanical and thermal properties of graphene were taken into account in our model for zigzag and armchair chiralities operating at different temperatures. The free in-plane vibration of the graphene nanoresonator is analyzed using Galerkin method. Decidedly, we show that the developed system of equations is capable of describing the TED behavior of graphene nanoresonators along the two considered chiralities during thermoelastic vibration. Specifically, we examined the influence of size, chirality, and temperature upon thermoelastic damping, as measured by the so-called quality factor, of the graphene nanoresonator. Our results reveal that the nanoresonator experiences higher energy dissipation with increased temperature. They also reveal the dependence of the energy dissipation upon the size and chirality of the graphene sheet.