This paper predicted nonlinear dynamic responses of a cantilevered carbon nanotube(CNT) resonator incorporating the electrostatic forces and van der Waals interactions between the CNT cantilever and ground plane. The structural model of CNT includes geometric and inertial nonlinearities to investigate various phenomena of nonlinear responses of the CNT due to the electrostatic excitation.In order to solve this problem, we used Galerkin's approximation and the numerical integration techniques. As a result, the CNT nano-resonator shows the softening effect through saddle-node bifurcation near primary resonance frequency with increasing the applied AC and DC voltages. Also we can predict nonlinear secondary resonances such as superharmonic and subharmonic resonances.The superharmonic resonance of the nano-resonator is influenced by applied AC voltage. The period-doubling bifurcation leads to the subharmonic resonance which occurs when the nano-resonator is actuated by electrostatic forces as parametric excitation. 는 선형보로 가정한 CNT의 구형파 전압가진

A commercially available soft lead titanate zirconate (PZT ) wafer that is poled in thickness direction is subjected to various magnitudes of constant longitudinal tensile stress. The evolutions of electric displacement in thickness direction and longitudinal strain over time are measured. The measured total responses are divided into linear responses, immediate switching-induced responses, and creep responses. It is found that immediate switching-induced responses can be described by stress power functions and creep responses by stress and time power laws, within the current range of tensile stress.

No abstract

No abstract

No abstract