FEM of MEMS on ANSYS

1
FEM of MEMS on ANSYS
MEMS Summer 2007

• Why FEM for MEMS?
• Features in ANSYS
• Basic Procedures
• Examples

2
Purpose of FEA
MEMS Summer 2007

• Make development cycle short and cost effective
• To understand behaviors, limits and interactions
  of complex processes
• To optimize designs
• For failure analysis

3
ANSYS Environment
MEMS Summer 2007

• 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.

4
Processors
MEMS Summer 2007

• Start with Begin level Job name, File name, etc
• Preprocessor Model creation
• Solution Processor - Apply Loads and Solving
• Postprocessors - Analyzing Results

5
GUI vs Codes
MEMS Summer 2007

• 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

6
Model Creation
MEMS Summer 2007

• Import or Create
• To create - Keypoints, lines, areas and volumes
• Material properties and real constants
• Element type and Meshing

7
Units
MEMS Summer 2007
8
Applying Loads
MEMS Summer 2007

• Boundary Conditions
• Various Types of Loads
• Structural displacements, forces, pressures,
  temperatures (for thermal strain), gravity
• Thermal temperatures, heat flow rates,
  convections, internal heat generation, infinite
  surface
• Electrical 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

9
Solution and View Results
MEMS Summer 2007

• 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

10
Example
MEMS Summer 2007

• Lets follow Multiphysics Analysis of a Thermal
  Actuator in Ansys Tutorial