Thermoelastic damping in nanobeam resonators based on effective nonlocal stress model

Abstract

Thermoelastic damping (TED) is a decisive component of the quality factor of Micro-electro-mechanical Systems (MEMS) and Nano-electro-mechanical Systems (NEMS) under vacuum. Nanobeam resonator is a key element of NEMS and the modeling of TED in nanobeams is a crucial task. With the miniaturization of resonators, the mechanical behavior of structures is influenced by size effects and the classical continuum mechanics is no longer precise. Eringen’s nonlocal elasticity theory is a popular size-dependent theory and there have been some TED researches based on it. However, the previous nonlocal models failed to explain the stiffness-enhancement mechanism observed in experiments. In this paper, we derive an analytical TED model for nanobeams based on Lim’s effective nonlocal stress model. Subsequently, the validity of the obtained model is proved and the effect of nonlocal elasticity on TED is discussed under different conditions.