CAE Software【Femtet】Murata Software Co., Ltd.
Example13 Resonant Frequency
General
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The model is a device with two reversely polarized piezoelectric bars stuck together. It is subjected to the tensile force, and the resonant frequency changes.
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Analysis with the initial stress taken into account is performed. See Analysis with the initial stress taken into account for the details.
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The device’s displacement and the resonant frequencies are solved.
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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
The analysis type is resonant analysis.
|
Item |
Settings |
|
Solvers |
Piezoelectric Analysis [Rayleigh] |
|
Analysis Type |
Resonant analysis |
|
Options |
Analysis with the initial stress taken into account Select Take into account Select Specify static load for boundary condition. |
The resonant analysis tab is set up as follows.
|
Tab |
Setting Item |
Settings |
|
Resonant analysis |
Number of modes |
3 |
|
Approximated frequency |
0[Hz] |
Model
Two reversely polarized piezoelectric bars are stuck together. The ends are set with the “pressure” boundary condition. The top and bottom faces are set with the “voltage specified” boundary condition.
Body Attributes and Materials
|
Body Number/Type |
Body Attribute Name |
Material Name |
|
0/Solid |
upper |
000_P-4 * |
|
1/Solid |
lower |
000_P-4 * |
* Available from the Material DB
Boundary Conditions
|
Boundary Condition Name/Topology |
Tab |
Boundary Condition Type |
Settings |
|
earth/Face |
Electric |
Electric wall |
Voltage specified: Voltage 0[V] |
|
hot/Face |
Electric |
Electric wall |
Voltage specified: Voltage 10[V] |
|
f_left/Face |
Mechanical |
Pressure |
-1×10^9[Pa] |
|
f_right/Face |
Mechanical |
Pressure |
-1×10^9[Pa] |
Results
The displacement diagram of Mode[0] is shown below.
The resonant frequency is 4.481E+4[Hz].
On the [Results] tab
click [Table] 
.
The table below shows the resonant frequencies.
Other characteristics can be seen on other tabs.
The table below is the results with the tensile force set to 0.
The tensile force affects the resonance.