Harmonic analysisexamples|products|Murata Software Co., Ltd.

Example1 Harmonic analysis

General

  • The model is a piezoelectric disc. The AC voltage applied across the top and bottom faces generates the vibration.
    The sound waves are radiated as a result.
     

  • This is a piezoelectric-acoustic coupled analysis.
     

  • Unless specified in the list below, the default conditions will be applied.

 

  • Please set the analysis domains in body attributes properly.
    Follow the settings on Body Attributes and Material Properties below.
     

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

m

 

Analysis Conditions

The solvers are Rayleigh and Mach.

Item

Settings

Solver

Piezoelectric Analysis [Rayleigh]

Acoustic Analysis [Mach]

Analysis Type

Harmonic analysis

Options

N/A

The harmonics analysis tab is set up as follows.

The sound waves propagate outside the analysis region. Therefore the “open boundary” condition below is applied initially.

Tabs

Setting Item

Settings

Harmonic analysis

Frequency

Minimum: 2000[Hz]

Maximum: 2000[Hz]

Step

Division number: 0

Open Boundary Tab

Type

Absorbing boundary

Order of Absorbing Boundary

1st degree

Coordinates of Origin

x = y = z = 0

 

Model

A piezoelectric disc (Unit) is placed on an aluminum disc (Plate). The hemispheric body (Air) covers the upper area.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

Air

000_Air(*)

1/Solid

Unit

000_P-4 *

2/Solid

Plate

001_Al *

* Available from the Material DB

 

Unit and Plate are for the piezoelectric analysis only, whereas Air is for the acoustic analysis only.

 

Body Attribute Name

Analysis Domains/Usable Domains

Unit

For use in Piezoelectric Analysis/Coulomb

Plate

For use in Piezoelectric Analysis/Coulomb

Air

For use in Acoustic Analysis/Mach

 

Cautions:

In this analysis, it is necessary to specify the analysis domain.

Specify either piezoelectric analysis or acoustic analysis as the usable domain on the analysis domain tab.

Boundary Conditions

The side periphery of the model is fixed in the Z direction.

Electric wall is set on the top and bottom faces of the piezoelectric disc.

The open boundary is set on the hemispheric surface.

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

V0/Face

Electric

Electric wall

Voltage specified: Voltage 0[V]

V1/Face

Electric

Electric wall

Voltage specified: Voltage 10[V]

Fix/Face

Mechanical

Displacement

Select UZ and set UZ=0

Open

Acoustic

Open boundary

 

 

Results

The magnitude of displacement is shown below.

The largest displacement is indicated in the center area.

 

The contour of the sound pressure on the XZ section is shown below.

The sound waves are propagating from the top of the device.