You can create an acoustic pressure boundary condition to specify the pressure for the selected region of an acoustic medium. (For more information, see Boundary Conditions, in Acoustic, shock, and coupled acoustic-structural analysis, Section 6.9.1 of the ABAQUS Analysis User's Manual.)
To specify an acoustic pressure:
Display the acoustic pressure boundary condition editor using one of the following methods:
To create a new acoustic pressure boundary condition, follow the procedure outlined in Creating boundary conditions, Section 16.8.2 (Category: Other; Types for Selected Step: Acoustic pressure).
To edit an existing acoustic pressure boundary condition using menus or managers, see Editing step-dependent objects, Section 3.4.12. To edit the region to which the boundary condition is applied, see Editing the region to which a prescribed condition is applied, Section 16.8.4.
If a Method field appears toward the top of the editor, click the arrow to the right of the field, and select one of the following:
Select Specify magnitude if you want to specify a value for the acoustic pressure.
Select Fixed at current magnitude if you want to fix the acoustic pressure magnitude at its final value from the previous general step.
If a Distribution field appears in the editor, click the arrow to the right of the field, and select one of the following:
Select Uniform to define a uniform boundary condition.
Select User-defined to define the boundary condition in user subroutine DISP. See the following sections for more information:
If you are defining the boundary condition directly in the editor (and not in user subroutine DISP), perform the following steps:
If applicable, enter the magnitude of the acoustic pressure in the Magnitude field.
If applicable, click the arrow to the right of the Amplitude field, and select the amplitude of your choice from the list that appears. Alternatively, you can click Create to create a new amplitude. (See Chapter 38, The Amplitude toolset,” for more information.)
Note: The Magnitude and Amplitude fields are unavailable if you are creating the boundary condition in the initial step (in which case the magnitude is always zero) or are fixing the magnitude at its final value from the previous analysis step.
Click OK to save your data and to exit the editor.
If you are defining the boundary condition in user subroutine DISP, perform the following steps:
If desired, enter the acoustic pressure magnitude in the Magnitude field. Magnitude data that you enter in the editor are passed into the user subroutine.
(The Magnitude field is unavailable if you are creating the boundary condition in the initial step.)
Click OK to save any entered data and to exit the editor.
Enter the Job module, and display the job editor for the analysis job of interest. (For more information, see Creating, editing, and manipulating jobs, Section 18.5.)
In the job editor, click the General tab, and specify the file containing the user subroutine that defines the boundary condition. For more information, see Specifying general job settings, Section 18.6.6.
Note: You can specify only one user subroutine file in the job editor; if your analysis involves more than one user subroutine, you must combine the user subroutines into one file and then specify that file.