Mechanical Behavior of a FGM Capacitive Micro-Beam Subjected to a Heat Source

Subject Areas : Engineering

I JafarSadeghi-Pournaki ¹ , M.R Zamanzadeh ² , R Shabani ³ , G Rezazadeh ⁴

1 - Mechanical Engineering Department, Urmia University
2 - Mechanical Engineering Department, Urmia University
3 - Mechanical Engineering Department, Urmia University
4 - Mechanical Engineering Department, Urmia University

Received: 2011-05-03 Accepted : 2011-06-27 Published : 2011-06-30

Keywords: Pull-in voltage, FGM Cantilever micro-beam, Euler–Bernoulli, Size-dependent, Exponential volume fraction law,

Abstract :

This paper presents mechanical behavior of a functionally graded (FG) cantilever micro-beam subjected to a nonlinear electrostatic pressure and thermal moment considering effects of material length scale parameters. Material properties through the beam thickness direction are graded. The top surface of the micro-beam is made of pure metal and the bottom surface from a mixture of metal and ceramic. The material properties through the thickness direction follow the volume fraction of the constitutive materials in exponential function form. The governing nonlinear thermo-electro-mechanical differential equation based on Euler-Bernoulli beam theory assumptions is derived using modified couple stress theory (MCST) and is solved using the Galerkin based weighted residual method. The effects of the electrostatic pressure and temperature changes on the deflection and stability of the FGM micro-beam, having various ceramic constituent percents, are studied. The obtained results are compared with the results predicted by classic theory (CT) and for some cases are verified with those reported in the literature.

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