MEMS Summer 2007

FEM of MEMS on ANSYS

• Why FEM for MEMS?

• Features in ANSYS • Basic Procedures • Examples ANSYS for MEMS by Manjula 1

MEMS Summer 2007

Purpose of FEA

• Make development cycle short and cost effective • To understand behaviors, limits and interactions of complex processes • To optimize designs • For failure analysis ANSYS for MEMS by Manjula 2

MEMS Summer 2007

ANSYS Environment

• Has GUI and Coded (for Batch Mode) command interfaces • Enable to both creation and importing of models • Capable of Linear and Non-linear analysis on the phenomena of Structural, Thermal, Electromagnetic, Electrostatics, Fluid, etc .

• Ability to simulate Coupled-field behaviors.

ANSYS for MEMS by Manjula 3

MEMS Summer 2007

Processors

• Start with

Begin level

–

Job name, File name, etc •

Preprocessor

– Model creation •

Solution Processor

- Apply Loads and Solving •

Postprocessors

- Analyzing Results ANSYS for MEMS by Manjula 4

MEMS Summer 2007

GUI

vs Codes

• Advantage of Repetition and parametric design with codes • Easy to follow and to visualize with GUI • Over 1200 commands with specific syntaxes for codes • Help file for each command on codes • Batch mode execution by codes ANSYS for MEMS by Manjula 5

MEMS Summer 2007

Model Creation

• Import or Create • To create -

Keypoints, lines, areas and volumes

• Material properties and real constants • Element type and Meshing ANSYS for MEMS by Manjula 6

MEMS Summer 2007

Units

ANSYS for MEMS by Manjula 7

MEMS Summer 2007

Applying Loads

• Boundary Conditions • Various Types of Loads – Structural – Thermal

displacements, forces, pressures, temperatures (for thermal strain), gravity temperatures, heat flow rates, convections, internal heat generation, infinite surface

– Electrica l

electric potentials (voltage), electric current, electric charges, charge densities, infinite surface

– Fluids –

velocities, pressures Magnetic potentials, magnetic flux, magnetic current segments, source current density, infinite surface

• Can apply loads in Steps ANSYS for MEMS by Manjula 8

MEMS Summer 2007

Solution and View Results

• Specify analysis type and solve • Post1 is used to review results from static or steady state problems • Post26 is used to review results from transient problems.

• Reading results by… – By Sets – Load Step (LS) – Time/frequency ANSYS for MEMS by Manjula 9

MEMS Summer 2007

Example

• Let’s follow Multiphysics Analysis of a Thermal Actuator in Ansys Tutorial ANSYS for MEMS by Manjula 10