Veijola T. – TechConnect Briefs

Analytic Damping Model for a Square Perforation Cell

Veijola T., Helsinki University of Technology, FI

A compact model for a square perforation cell is derived. It is generated both analytically and with 3D FEM simulations of the structure. The model consists of six flow resistances, whose values are simple functions [...]

A Method for Solving Arbitrary MEMS Perforation Problems with Edge and Rare Gas Effects

Veijola T., Helsinki University of Technology, FI

We present an accurate and fast method solving arbitrary perforation problems utilizing a solver for an extended modified Reynolds equation, the Local Impedance Reynolds (LIR) solver. The extension includes an additional term in the Reynolds [...]

Extending the Validity of Existing Squeezed-Film Damper Models with Elongations of Surface Dimensions

Veijola T., Pursula A., Helsinki University of Technology, FI

Border flow effects in squeezed-film dampers having a gap separation comparable with the surface dimensions are studied with 2D and 3D FEM simulations and with analytic models derived from the linearized Reynolds equation for small [...]

Model for Flow Resistance of a Rare Gas Accounting for Surface Roughness

Veijola T., Helsinki University of Technology, FI

The contribution of surface roughness is included in the flow resistance of rare gas flow channels. The statistical properties of the surface are taken into account in the model applying a novel approximation for the [...]

Hierarchical Finite Element Simulation of Perforated Plates with Arbitrary Hole Geometries

Råback P., Pursula A., Junttila V., Veijola T., CSC - Scientific Computing, FI

The squeezed-film-damping of micro-electro-mechanical devices may be reduced by creating a number of small holes into the structure. Unfortunately, in the simulation of the devices it is possible to consider only a few holes in [...]

Static Equivalent Circuit Model for a Capacitive MEMS RF Switch

Tinttunen T., Veijola T., Nieminen H., Ermolov V., Ryhanen T., Helsinki University of Technology, FI

A simulation model for static analysis of a doubly supported capacitive MEMS RF switch has been constructed using electrical equivalencies. Energy-conserving large-displacement macro models for beam deflection, gap capacitance, electrostatic force, and mechanical contact are [...]

Authors: Veijola T.

Analytic Damping Model for a Square Perforation Cell

A Method for Solving Arbitrary MEMS Perforation Problems with Edge and Rare Gas Effects

Extending the Validity of Existing Squeezed-Film Damper Models with Elongations of Surface Dimensions

Model for Flow Resistance of a Rare Gas Accounting for Surface Roughness

Hierarchical Finite Element Simulation of Perforated Plates with Arbitrary Hole Geometries

Static Equivalent Circuit Model for a Capacitive MEMS RF Switch

End Effects of Rare Gas Flow in Short Channels and in Squeezed-Film Dampers

Acoustic Impedance Elements Modeling Oscillating Gas Flow in Micro Channels

Compact Model for the Squeezed-Film Damping Including the Open Border Effects

Compact Damping Models for Lateral Structures Including Gas Rarefaction Effects