To specify the acoustic wave formulation for the model:

• If your model contains incident wave interactions, you must edit the model attributes to specify an acoustic wave formulation. You select a scattered wave formulation or a total wave formulation using the procedure described in “Editing model attributes,” Section 9.8.4. The formulation that you select applies for all of the incident wave interactions in your model. For more information, see “Scattered and total wave formulations” in “Acoustic loads,” Section 27.4.5 of the ABAQUS Analysis User's Manual.

To define an incident wave interaction:

From the main menu bar, select InteractionCreate.

Tip:  You can also create an incident wave interaction using the tool in the Interaction module toolbox.

In the Create Interaction dialog box that appears, do the following:

Name the interaction. For more information about naming objects, see “Using basic dialog box components,” Section 3.2.1.

Select the step. You can define an incident wave interaction only during an implicit or explicit dynamic analysis. An incident wave interaction is active only in the step in which it is created.

Select the Incident wave type of interaction.

Click Continue to close the Create Interaction dialog box.

Use one of the following methods to select the incident wave source point:

Use an existing set to define the region. The set must contain a single point or vertex. On the right side of the prompt area, click Sets. Select an existing set from the Region Selection dialog box that appears, and click Continue.

Note:  The default selection method is based on the selection method you most recently employed. To revert to the other method, click Select in Viewport or Sets on the right side of the prompt area.

Use the mouse to select a node or vertex in the viewport. (For more information, see “Selecting objects within the current viewport,” Section 6.2.)

If the model contains a combination of orphan mesh instances and native geometric part instances, click one of the following from the prompt area:

• Click Geometry if you want to select vertices from native geometry.

• Click Mesh if you want to select nodes from an orphan mesh.

The source point that you select becomes highlighted in red in the viewport.

Using one of the methods described in the previous step, select the incident wave standoff point.

The standoff point that you select becomes highlighted in green in the viewport.

Use one of the following methods to select the surface:

Use an existing surface to define the region. On the right side of the prompt area, click Surfaces. Select an existing surface from the Region Selection dialog box that appears, and click Continue.

Note:  The default selection method is based on the selection method you most recently employed. To revert to the other method, click Select in Viewport or Surfaces on the right side of the prompt area.

Use the mouse to select a region in the viewport.

The surface or region that you select becomes highlighted in magenta in the viewport.

In the Edit Interaction dialog box that appears, click the arrow to the right of the Definition field; and select the option of your choice from the list that appears:

Select Pressure to specify the fluid pressure time history at the standoff point.

Select Acceleration to specify the fluid particle acceleration time history at the standoff point.

Select UNDEX to specify UNDEX bubble data.

In the Wave Data portion of the editor, perform the following steps:

Select an incident wave interaction property. If desired, click Create to create the interaction property; see “Defining an incident wave interaction property,” Section 15.13.4, for more information. The following requirements exist:

If you selected the UNDEX definition option, you must select an interaction property that contains UNDEX bubble data.

If you selected the Pressure or Amplitude definition option, you must select an interaction property that does not contain UNDEX bubble data.

In the Reference magnitude field, enter the reference magnitude used to scale the values given in the amplitude definition.

If you selected the Pressure or Acceleration definition option, click the arrow to the right of the Pressure amplitude or Acceleration amplitude field in the Standoff Point portion of the editor; and select the amplitude of your choice from the list that appears. If desired, click Create to create a new amplitude; see “Creating an amplitude,” Section 38.3, for more information.

If you selected the UNDEX definition option, in the UNDEX Data portion of the editor, perform the following steps:

In the Direction cosine of fluid surface normal field, enter the X-component, Y-component, and Z-component of the direction cosine of the fluid surface normal.

In the Initial depth field, enter the initial depth of the UNDEX charge.

Click OK to create the interaction and to close the editor.