You use an acoustic impedance interaction property to define the proportionality factors between the pressure and the normal components of surface displacement and velocity in an acoustic analysis. An acoustic impedance interaction property can be referred to only by an acoustic impedance interaction. For more information, see “Defining acoustic impedance,” Section 15.12.9.
To define an acoustic impedance interaction property:
From the main menu bar, select Interaction
PropertyCreate.
In the Create Interaction Property dialog box that appears, do the following:
Name the interaction property. For more information about naming objects, see “Using basic dialog box components,” Section 3.2.1.
Select the Acoustic impedance type of interaction property.
Click Continue to close the Create Interaction Property dialog box.
From the Data type field, choose the type of tabular data that you will use to define the acoustic impedance.
Select Impedance to specify an impedance using real and imaginary parts of the impedance.
Select Admittance to specify an impedance using admittance values.
Toggle on Use frequency-dependent data to define an acoustic impedance that varies with frequency. A column labeled Frequency appears in the data table.
If you are using impedance data, enter the following data in the table:
If you are using admittance data, enter the following data in the table:
, the proportionality factor between pressure and velocity of the surface in the normal direction. This quantity is the real part of the complex admittance. (Units of F–1L3T–1.)
, the proportionality factor between pressure and displacement of the surface in the normal direction. This quantity is the imaginary part of the complex admittance, divided by the angular frequency. (Units of F–1L3.)
Click OK to create the acoustic impedance interaction property and to exit the editor.
, the real part of the surface impedance. (Units of 
, the imaginary part of the surface impedance. (Units of