FRF set workflow

You create an FRF set using the Simcenter Nastran Structural or MSC Nastran SOL108 Direct Frequency Response Functions or SOL111 Modal Frequency Response Functions solutions or the SOL 111 Modal Frequency Response Functions vibro-acoustic solution.

Step	Summary	Detailed help topic
1.	In a FEM file, create any desired PLOTEL elements.	Use PLOTEL elements to visualize a complex model and to define connection nodes in an FRF set.
2.	Create a Simulation file.		Create a new Simulation file
3.	In the Simulation file, create a structural or vibro-acoustic solution.	Set the Solver to Nastran, the Analysis Type to Structural and solution to SOL108 Direct Frequency Response Functions or SOL111 Modal Frequency Response Functions or for a vibro-acoustic Solution set the solution to SOL111 Modal Frequency Response Functions.	Create or modify a solution
4.	Edit the subcase to specify output requests.	In the FRF Output Requests dialog box, select the types of responses to be output and then select the mesh or nodes to be output.Note: If you are selecting the output of only a few nodes, set Sorting to SORT2.	Structural, FRF, and Thermal Output Requests dialog boxes (Nastran)
5.	Edit the subcase to create forcing frequencies to excite the model.	In the Forcing Frequencies dialog box, specify the range of frequencies or individual forcing frequencies.	Forcing Frequencies dialog box (Nastran)
6.	Create excitation loads.	Create Unit Force or United Enforced Motion at selected nodes, mesh, or groups.	Unit Force dialog boxUnit Enforced Motion dialog box
7.	Create desired structural constraints.	Constrain the model and add the constraint set to the solution.Note: If the model is unconstrained, and you set the lowest frequency to 0.1 Hz to remove rigid body modes, this step is unnecessary.	Define user-defined constraints
8.	Solve the solution.	The solver computes the frequency responses.	Solve the model
9.	Post-process the analysis results to ensure the solution results are correct.	You can display the FRF results using standard post-processing or with the post-processing scenarios.	Scenario-based post-processing
10.	Save the FEM and Simulation model.

How do I

FRF set in assembly FEM workflow

Replace a FEM file with a mode set or FRF set

Add a new FEM component from an FRF set to an assembly FEM

Editing modes or functions in mode sets and FRF sets

Edit a mode set or FRF set

Learn more

FRF sets

Using Modal Expansion to expand measurements to a FEM

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Assembly FEM

FRF set workflow, Simcenter 3D 2021.1 Series

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