MODELING SQUEEZE-FILM DAMPING OF ELECTROSTATICALLY ACTUATED MICROPLATES UNDERGOING LARGE DEFLECTIONS

摘要

A model for the dynamics of electrostatically actuated microplates undergoing large deflections under the effect of squeeze-film damping is presented. The model predicts the quality factors of microplates under a wide range of gas pressures and applied electrostatic forces up to the pull-in instability. The model utilizes the nonlinear Euler-Bernoulli beam equation, the von Karman plate equations, and the compressible Reynolds equation. The static deflection of the microplate is calculated using the beam model. Analytical expressions are derived for the pressure distribution in terms of the plate mode shapes around the deflected position using perturbation techniques. The static deflection and the analytical expressions are substituted into the plate equations, which are solved using a finite-element method. Several results are presented showing the effect of the pressure and the electrostatic force on the structural mode shapes, the pressure distributions, the natural frequencies, and the quality factors.