FRF set in assembly FEM workflow

To use a frequency response model in an assembly FEM, you create an FRF set from an imported frequency response function model. An FRF set is a component representation of a FEM that you can use in structural, acoustic, or vibro-acoustic solutions (SOL 103, SOL 108, or SOL 111), or in a Response Dynamics analysis.

You can also import results from a Simcenter Testlab file to use as an FRF set.

Step	Summary	Detailed help topic
1.	Create an assembly FEM or open an existing assembly FEM.		Assembly FEM fileCreate an assembly FEM fileAdd an existing FEM to an assembly FEMAdd a new FEM to an assembly FEMPositioning component and subassembly FEMs within an assembly FEM
2.	Replace a FEM component with an FRF set by editing the FEM representation.	Right-click the component FEM that you will use as a modal model and choose Make Work Part.Right-click the FEM and choose Edit Representation.
3.	Create an FRF Set.	In the FE Model Component Representation dialog box, select FRF Set.Click Create FEM Data Set .Name the FRF set.Use the file browser to select the desired .op2 file from Simcenter Nastran, or results from Simcenter Testlab, to import the frequency response information.	Alternate representation (component FEM file)
4.	Select the FRF set display.	In the FE Model Component Representation dialog box, select an option to display the set:Associated Elements: Only elements with FRF set data are displayed.Visualization Elements: The software uses only PLOTELs that you created and stored in the Simcenter Nastran .op2 file.Next select how the FRF set will be displayed.None: User defined PLOTELS and the nodes are displayed.Approximation of base FEM: The software approximates the mesh using PLOTELs.Superelement Symbol: A spider element is displayed from the nodes to the component center.
5.	Edit the FRF Set.	Edit the FRF set to activate or deactivate modes. Apply or edit modal damping for active modes as needed.	Editing modes or functions in mode sets and FRF sets
6.	Create elastic connectors to attach components together.	Use elastic elements (such as springs or beams) to connect components.Note: An FRF set is a collection of MPCs, so you cannot use rigid elements or multipoint constraints to connect FRF sets to other components. Using rigid elements or multipoint constraints will cause dependency conflicts.	Point-to-point and node-to-node connectionsConnecting component FEMs
7.	Resolve any component FEM label conflicts.	Use the Assembly Label Manager to apply label offsets to resolve any label conflicts in the assembly FEM.	Resolve label conflicts in your assembly FEM files
8.	Create the assembly Simulation file.	In the Simulation file, specify solutions, loads, constraints, and output requests.
9.	Make the Simulation file the Work Part.	Right-click the Simulation file and choose Make Work Part.
10.	Create a new solution.	Set the Solver to Nastran, the Analysis Type to Structural, and the Solution Type to one of the following:SOL103 Real EigenvaluesSOL108 Direct Frequency ResponseSOL111 Modal Frequency Response	Create or modify a solution
11.	Create an output request.	Request the output types for your solution.	Requesting output for Nastran analyses
12.	Create constraints.	Define any desired structural constraints.	Constraint sets
13.	Create applied forces, frequency excitation, or the frequency range.	Define the desired forces, excitations, or solution frequency range.	Define the frequency range and number of modes to solve
14.	Solve the solution.		Solve the model
15.	Post-process the results.		Scenario-based post-processing

How do I

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

FRF set workflow

Using Modal Expansion to expand measurements to a FEM

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Related Topics

Assembly FEM

FRF set in assembly FEM workflow, Simcenter 3D 2021.1 Series

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