A numerical study of squeeze-film damping in MEMS-based structures including rarefaction effects
Journal Title: Frattura ed Integrità Strutturale - Year 2013, Vol 7, Issue 23
Abstract
In a variety of MEMS applications, the thin film of fluid responsible of squeeze-film damping results to be rarefied and, thus, not suitable to be modeled though the classical Navier-Stokes equation. The simplest way to consider fluid rarefaction is the introduction of a slight modification into its ordinary formulation, by substituting the standard fluid viscosity with an effective viscosity term. In the present paper, some squeeze-film damping problems of both parallel and torsion plates at decreasing pressure are studied by numerical solving a full 3D Navier-Stokes equation, where the effective viscosity is computed according to proper expressions already included in the literature. Furthermore, the same expressions for the effective viscosity are implemented within known analytical models, still derived from the Navier-Stokes equation. In all the considered cases, the numerical results are shown to be very promising, providing comparable or even better agreement with the experimental data than the corresponding analytical results, even at low air pressure. Thus, unlike what is usually agreed in the literature, the effective viscosity approach can be efficiently applied at low pressure regimes, especially when this is combined with a finite element analysis (FEA).
Authors and Affiliations
Maria F. Dept. of Mechanical Engineering, University of Calabria, 87036 Rende (CS), Italy. , Leonardo Pagnotta, Salvatore Nigro
Keywords
Related Articles
- EP ID EP119960
- DOI 10.3221/IGF-ESIS.23.11
- Views 66
- Downloads 0
Transverse strength of railway tracks: part 1. Planning and experimental setup
Several studies have been carried out until now by various Research Agencies and Railway Administrations to quantify the effects of the track-bed geometrical characteristics on the transverse strength of the trac...
Crack simulation models in variable amplitude loading - a review
This work presents a review of crack propagation simulation models considering plane stress and plane strain conditions. It is presented also a chronological different methodologies used to perform the crack ...
Effect of centrifugal load on crack path in thin-rimmed and webbed gears
Thin rimmed and webbed gears are used in particular applications to reduce systems weight. This kind of gears need an accurate and fail safe design. As a matter of fact, a possible failure, due to bending fatigue,...
Application of thermoelastic stress analysis for the experimental evaluation of the effective stress intensity factor
In recent years, the advent of staring array detectors has made Thermoelastic Stress Analysis (TSA) a technique with considerable potential for fatigue and fracture mechanics applications. The technique is non-cont...
Static assessment of brittle/ductile notched materials: an engineering approach based on the Theory of Critical Distances
Engineering components often contain notches, keyways or other stress concentration features. These features raise the stress state in the vicinity of their apex which can lead to unexpected failure of the compone...