MODELING THE SIZE DEPENDENT PULL-IN INSTABILITY OF BEAM-TYPE NEMS USING STRAIN GRADIENT THEORY

Authors

  • ALI KOOCHI SHAHREKORD BRANCH, ISLAMIC AZAD UNIVERSITY, SHAHREKORD, IRAN
  • HAMID M. SEDIGHI DEPARTMENT OF MECHANICAL ENGINEERING, SHAHID CHAMRAN UNIVERSITY, AHVAZ, 61357-43337 IRAN
  • MOHAMADREZA ABADYAN SHAHREKORD BRANCH, ISLAMIC AZAD UNIVERSITY, SHAHREKORD, IRAN,

Keywords:

STRAIN GRADIENT THEORY, PULL-IN INSTABILITY, NANO-CANTILEVER, NANO-BRIDGE, DISPERSION FORCES, SIZE EFFECT

Abstract

IT IS WELL RECOGNIZED THAT SIZE DEPENDENCY OF MATERIALS CHARACTERISTICS, I.E. SIZE-EFFECT, OFTEN PLAYS A SIGNIFICANT ROLE IN THE PERFORMANCE OF NANO-STRUCTURES. HEREIN, STRAIN GRADIENT CONTINUUM THEORY IS EMPLOYED TO INVESTIGATE THE SIZE DEPENDENT PULL-IN INSTABILITY OF BEAM-TYPE NANO-ELECTROMECHANICAL SYSTEMS (NEMS). TWO MOST COMMON TYPES OF NEMS I.E. NANO-BRIDGE AND NANO-CANTILEVER ARE CONSIDERED. EFFECTS OF ELECTROSTATIC FIELD AND DISPERSION FORCES I.E. CASIMIR AND VAN DER WAALS (VDW) ATTRACTIONS HAVE BEEN CONSIDERED IN THE NONLINEAR GOVERNING EQUATIONS OF THE SYSTEMS. TWO DIFFERENT SOLUTION METHODS INCLUDING NUMERICAL AND RAYLEIGH-RITZ HAVE BEEN EMPLOYED TO SOLVE THE CONSTITUTIVE DIFFERENTIAL EQUATIONS OF THE SYSTEM. EFFECT OF DISPERSION FORCES, THE SIZE DEPENDENCY AND THE IMPORTANCE OF COUPLING BETWEEN THEM ON THE INSTABILITY PERFORMANCE ARE DISCUSSED.

Published

2014-07-05

Issue

Section

Articles