NUMERICAL STUDY ON PULL-IN INSTABILITY ANALYSIS OF GEOMETRICALLY NONLINEAR EULER-BERNOULLI MICRO BEAM BASED ON MODIFIED COUPLE STRESS THEORY

Year 2012, Volume: 4 Issue: 4, 41 - 53, 01.12.2012

Y. Tadi Beni M. Heidari

Abstract

In this paper, the static pull-in instability of beam-type micro-electromechanical systems (MEMS) is theoretically investigated. Two engineering cases including cantilever and double cantilever micro-beam are considered. Considering the mid-plane stretching as the source of the nonlinearity in the beam behavior, a nonlinear sizedependent Euler-Bernoulli beam model is used based on a modified couple stress theory, capable of capturing the size effect. By selecting a range of geometric parameters such as beam lengths, width, thickness, gaps and size effect, we identify the static pull-in instability voltage. A MAPLE package is employed to solve the nonlinear differential governing equations to obtain the static pull-in instability voltage of microbeams. The results reveal significant influences of size effect and geometric parameters on the static pull-in instability voltage of MEMS

Keywords

Nonlinear microbeam, modified couple stress theory, static pull-in instability, size effects

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