Thermoelastic damping in nonlocal rod using three-phase lag heat conduction model

Abstract

This manuscript studies thermoelastic damping of a longitudinally vibrating nanorod at small-scale. The heat conduction in the present work is constructed based on the three phase-lag heat conduction model and the elastic effects are modeled using nonlocal elasticity. Isothermal and adiabatic type of thermal boundary conditions are considered in the numerical analysis. It is found that the thermoelastic damping of the present resonator under adiabatic thermal boundary conditions is higher than that of the isothermal boundary conditions. The nonlocal elasticity gives higher thermoelastic damping than the classical elasticity. The present results are in good agreement with those of the available literature. Thermoelastic damping for clamped-clamped nanorod vibrating in longitudinal mode is 83% higher than that of the clamped-free nanorod for both adiabatic and isothermal boundary conditions. The critical length of nanorod at which the thermoelastic damping is maximum, is lower for the adiabatic condition than isothermal condition. The energy dissipation occurs at very fast rate at higher values of thermal relaxation parameters and more clearly this effect is seen for nanorod with less than 100 nm length. The numerical results presented in this work are useful for the design of the next generation nanoscale devices based on longitudinal resonators.