Nonlocal thermoelastic damping in carbon nanotube

Abstract

In the present work, thermoelastic damping of single-walled carbon nanotube is studied based on nonlocal continuum mechanics. The carbon nanotube is modeled as a thin elastic shell having three degrees of freedom in axial, circumferential and radial directions. Nonlocal continuum theory is incorporated in the classical thin shell model to capture the effects of nanoscale. The nonlocal coupled thermoelastic equations for carbon nanotubes are derived and simulation results on nanoscale dependent thermo-elastic damping are demonstrated. Numerical results show that the thermoelastic damping predicted by the classical continuum mechanics is over estimated as compare to the nonlocal continuum mechanics calculations. The effect of boundary conditions, size of nanotube and the initial axial stress on the thermo-elastic damping of carbon nanotubes is also investigated and discussed. It has been found that for simply- supported carbon nanotube, the thermoelastic damping becomes smaller while for clamped-clamped condition it becomes larger. Thus, it has been concluded that a simply supported carbon nanotube that vibrates in lower natural frequencies is a good choice for nano-electro-mechanical-system (NEMS) devices because of the minimum thermo- elastic damping.