Create nodal and enforced motion excitations

This topic describes how to create a nodal force or enforced motion excitation in translational or rotational directions.

Note:

This topic does not cover creating a rotating force excitation. For steps to create a rotating force excitation, see Create rotating force excitations.

1. Use the Functions and Graphing tools or the Response Dynamics Function Toolkit to create the XY table function to be used in the excitation.

2. Make sure the AFU file that contains your excitation function is open in the XY Function Navigator (in the XY Function Navigator, right-click AFU Files – XY Tabular Functions and choose Open).

3. In the Simulation Navigator, right-click the Excitations node (under the current Event node) and choose one of the following:New Excitation→Translational Nodal to create a nodal force or enforced motion excitation in the X, Y, or Z directions.New Excitation→Rotational Nodal to create a nodal force or enforced motion excitation in the RX, RY, or RZ directions.

4. In the New Translational Nodal Excitation or New Rotational Nodal Excitation dialog box, type a name for the excitation in the Name box.

5. Under Excitation, select Nodal Force or Enforced Motion. If you are using the Mode Acceleration data recovery method, you must have an excitation location of the same type already defined in your solved solution.

6. If this is an Enforced Motion excitation, in the Selection Method list, select the method for specifying the location of the excitation.To select the location of the excitation directly in the graphics window, select Graphic Selection. Continue the steps in Select a location in the graphics window.To select a previously defined excitation location, select List Selection. You can select a single combination of node ID and direction. Continue the steps in Select a location from a list.

7. If this is a Nodal Force excitation, continue the steps in Select a location in the graphics window or Type a node ID.

Select a location in the graphics window

1. Make sure the Select Object line on the dialog box is highlighted (if not, select it).

2. In the graphics window, select the location where you want to apply the excitation. The location you can select depends on the Data Recovery method you selected when you created the event:Data Recovery methodLocationMode DisplacementSelect any node on the model.Mode AccelerationSelect only the excitation location you created prior to solving. For information about creating excitation locations, see Specify excitation locations.

3. Continue the steps in Apply a function and complete the excitation definition.

Select a location from a list

Continue with these steps if you selected List Selection as the Selection Method.

1. Click .

2. In the Select Excitation Location dialog box, select a DOF from the list. Each listed DOF is a node ID and direction that is part of the excitation location you defined prior to solving the solution. You can choose one DOF. For information about creating excitation locations, see Specify excitation locations.

3. Click OK. The node ID appears in the ID box and is indicated with a label in the graphics window.

4. Continue the steps in Apply a function and complete the excitation definition.

Type a node ID

1. In the Label box under Node Label, type the ID of the node where you want to apply the excitation. You can apply the excitation at any node.

2. Click to confirm your entry.

3. Continue the steps in Apply a function and complete the excitation definition.

Apply a function and complete the excitation definition

1. Under Excitation Functions, select the direction of the excitation. The direction you can select depends on the Data Recovery method you selected when you created the event:Data Recovery method for eventDirectionMode DisplacementSelect any direction. You can click any of the direction check boxes or define a User-Defined Direction.Mode AccelerationSelect only the direction in which you defined the excitation location prior to solving.

2. Click the button that appears next to the Function box or select the direction check box and choose Function Manager.

3. In the XY Function Manager dialog box, select an existing function from the list. Only functions in open AFU files appear in the list. Functions in the list that have the correct abscissa and ordinate data types for your event type are shown in black. Functions with incorrect abscissa or ordinate data types for your event are shown in red and cannot be selected. Note: If you use multiple excitations in an event, the functions must have the same X Minimum and X Increment values. These values determine the number of points in the function. Functions with different numbers of points (or with the incorrect abscissa or ordinate data types for the excitation type) appear in red and cannot be selected.You can also click New to create a new function.

4. Click OK to accept the function and return to the excitation dialog box.

5. Under Scale Factor, for the direction of your excitation, type a scale value. The function typically represents the baseline value that you use for several different situations. The Scale Factor allows you to tailor the function's output for the specific situation.

6. Click OK to finish creating the excitation.

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Create nodal and enforced motion excitations, Simcenter 3D 2021.1 Series

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