Mechanical behaviors of electrostatic microresonators with initial offset imperfection: qualitative analysis via time-varying capacitors

摘要: This paper investigates analytically and numerically the effect of initial offset imperfection on mechanical behaviors microbeam-based resonators. Symmetry breaking DC actuation, due to different distances microbeam lower upper electrodes, is concerned. For qualitative analysis, time-varying capacitors are introduced a lumped parameter model, considering nonlinear electrostatic force midplane stretching microbeam, adopted examine system statics dynamics. The Method Multiple Scales (MMS) applied determine primary resonance solution under small vibration assumption. Meanwhile, Finite Difference (FDM) combined with Floquet theory utilized generate frequency response curves for medium- large-amplitude simulations. Static bifurcation, phase portrait Hamiltonian function firstly investigated inherent behaviors. Besides, basins attraction briefly depicted grasp effects AC excitation global Then, variation equivalent natural versus voltage analyzed. Results show that may induce complex rebound phenomenon as well separate branch secondary pull-in condition. In what follows, emergences softening, linear hardening classified through discussing key obtained from equation. New behavior induced by found, which exhibits much higher sensitivity voltage. Medium- in-well motions also investigated, indicating existence alternations softening Finally, parameters deduced via Galerkin procedure, case studies provided illustrate effectiveness whole analysis.