CAE Software【Femtet】Murata Software Co., Ltd.
Example8 Periodic Structure
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A piezoelectric bar with periodic structure is analyzed. The analysis is done for a base unit extracted from the bar.
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The periodic boundary condition is set on either face of the base unit.
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Unless specified in the list below, the default conditions will be applied.
Analysis Space
|
Item |
Settings |
|
Analysis Space |
3D |
|
Model unit |
mm |
Analysis Conditions
|
Item |
Settings |
|
Solver |
Piezoelectric analysis [Galileo] |
|
Analysis Type |
Resonant analysis |
|
Options |
N/A |
|
Tab |
Setting Item |
Settings |
|
Resonant analysis |
Number of modes |
3 |
|
|
Approximated frequency |
0[Hz] |
Model
Cut the model with planes of symmetry and set the “periodic” boundary condition on the sections. The top face of UNIT is fixed at 1[V].
The bottom face is fixed at 0[V].
Body Attributes and Materials
|
Body Number/Type |
Body Attribute Name |
Material Name |
|
4/Solid |
UNIT |
000_P-4 * |
* Available from the Material DB
Boundary Conditions
|
Boundary Condition Name/Topology |
Tab |
Boundary Condition Type |
Settings |
|
p1/Face |
Symmetry/Continuity |
Periodic |
|
|
p2/Face |
Symmetry/Continuity |
Periodic |
|
|
hot/Face |
Electric |
Electric wall |
Voltage 1[V] |
|
earth/Face |
Electric |
Electric wall |
Voltage 0[V] |
For the periodic boundary conditions, p1 and p2,
On the [Model] tab
click [Boundary Pair] 
and register the pair.
When “Add” is clicked, the dialog box below will appear.
Enter the phase difference of p1 and p2. If in phase, it will be 0[deg]. If completely out of phase, it will be 180[deg].
Click OK to finish.
Results
The displacement diagram is shown below. The contour indicates the displacement.
The boundary pair, p1 and p2, are displaced in the same magnitude.
