Quality factors for the nano-mechanical tubes with thermoelastic damping and initial stress

The Quality factors (Q-factor) are defined as the ratio of the kinetic and potential energy to dissipation for various damping mechanisms of structures. Therefore, improvement in the Q-factors is an important issue in micro- and nano-resonator applications for the high performance. Also, it is well known that the thermoelastic damping is more crucial than the other damping factors in a device. Thus, the vibration of nano-mechanical circular tube is investigated with thermoelastic damping and initial stress effects in this work. To simplify the shell equations for the transverse displacement-dominated problems, the Donnell-Mushtari-Vlasov (DMV) approach is adopted. Applying the stress function, the equations of motion for deflection, compatibility equation and heat conduction equation are derived. Using an iterative scheme, the natural frequencies and the Q-factors under the initial stress are obtained, and the influences of the dimensions of the shell, the mode numbers and initial stress are discussed in detail. (C) 2010 Elsevier Ltd. All rights reserved.