Command reference help topics
Design Constraint - Direct Frequency dialog box
| Modeling Object | |
|---|---|
| Name | Sets a unique name for the design constraint. |
| Label | Sets a unique integer for the modeling object.The dialog box automatically displays the next available modeling object number. However, you might want to change this if you use a particular series of numbers to identify certain types of modeling objects. |
| Properties | |
| Description | Sets a description for the design constraint.You can also click Description to open the Description dialog box. This lets you see more of the text that you type, as well as cut, copy, or paste text.This description appears only on this dialog box. |
| Response Definition | Response LabelSets a unique design response identifier.This label must begin with an alphabetic character and cannot exceed eight characters.Tip: To make it easier to identify this design constraint in the optimization spreadsheet, use a descriptive label.Response TypeSpecifies the response that you want to constrain.This list displays only responses that are appropriate for a direct frequency subcase.Element Specification MethodAppears when Response Type is set to Frequency Response Force (FRFORC) or Frequency Response Stress (FRSTRE).Specifies the method to use for selecting the elements to use for the response.Select Element Selection to select the elements using a group or the graphics window. Select Physical Property to select them using a physical property table.Element DimensionAppears when Element Specification Method is set to Element Selection.Specifies the element dimension, such as 3D for a tetrahedral mesh.The options that appear in this list vary, depending on your selection in the Response Type list.Element TypeAppears when Element Dimension is set to 0D or 1D.Specifies the type of element to use for the response.The options that appear in this list vary, depending on your selection in the Element Dimension list.TypeAppears when Element Specification Method is set to Physical Property.Specifies the type of physical property table to use for selecting the elements.The options that appear in this list vary, depending on your selection in the Response Type list.Physical Property Appears when Element Specification Method is set to Physical Property.Specifies the physical property table to use.If the list is extensive, click More Options to search for a particular physical property table or filter the list.You can also click Create Physical to create a new physical property table for the selected physical property type, or click Open Manager to edit an existing physical property table.Output FormatWhen the dynamic response is complex, specifies whether the solution output uses real/imaginary or magnitude/phase values.This option should match the Data Format setting for the structural output request modeling object for your solution. For example, if Data Format is set to REAL or IMAG, set Output Format to Real/Imaginary. If Data Format is set to PHASE, set Output Format to Magnitude/Phase.ComponentAppears when Response Type is set to Frequency Response Displacement (FRDISP), Frequency Response Velocity (FRVELO), Frequency Response Acceleration (FRACCL), or Frequency Response SPCForce (FRSPCF).Specifies the translational (X, Y, or Z) or rotational (RX, RY, or RZ) component associated with the tensor value that you want to use (real, imaginary, magnitude, or phase).The components are relative to the displacement coordinate system for the selected node.For example, to use the phase angle from the Y-displacement output for your response, you would set Data Format to PHASE for Displacement in the structural output request modeling object for your solution. In this dialog box, you would set Response Type to Frequency Response Displacement (FRDISP), Output Format to Magnitude/Phase, and Component to Y, Phase.Element ResultAppears when Response Type is set to Frequency Response Force (FRFORC) or Frequency Response Stress (FRSTRE).Specifies the element result to use as the response.The options that appear in this list vary, depending on your selection in the Response Type list and other element specification options.If Item Code appears in the list, you can select that and then specify the appropriate Simcenter Nastran item code.Item CodeAppears when Element Result is set to Item Code.Sets the Simcenter Nastran item code to use as the response.Note: For some element types, the response value depends on the location setting for the structural output request. You can set this in the case control for the solution.For more information about item codes, see Item Codes.Frequency Math Function TypeSpecifies how to determine the frequency response value.You can either select Value and then specify the value, or you can select a math function to compute the frequency response value across multiple frequencies:SUM—Uses the sum of the response values.AVG—Uses the average response value.SSQ—Uses the sum of the squares of the response values.RSS—Uses the square root of the sum of the squares of the response values.MAX—Uses the maximum response value.MIN—Uses the minimum response value.Frequency ValueAppears when Frequency Math Function Type is set to Value.Sets the frequency response value. |
| Node Selection | Appears when Response Type is set to Frequency Response Displacement (FRDISP), Frequency Response Velocity (FRVELO), Frequency Response Acceleration (FRACCL), or Frequency Response SPCForce (FRSPCF). Group ReferenceLets you select nodes by selecting a group.For more information, see Group Reference options.Select Node Available when the Group Reference check box is cleared.Lets you select nodes in the graphics window.ExcludedLets you exclude certain nodes from selection. |
| Element Selection | Appears when Element Specification Method is set to Element Selection. Group ReferenceLets you select elements by selecting a group.For more information, see Group Reference options.Select 0D Element Appears when Element Dimension is set to 0D. Available when the Group Reference check box is cleared.Lets you select 0D elements in the graphics window.Select 1D Element Appears when Element Dimension is set to 1D. Available when the Group Reference check box is cleared.Lets you select 1D elements in the graphics window.Select 2D Element Appears when Element Dimension is set to 2D Shell or 2D Shear. Available when the Group Reference check box is cleared.Lets you select 2D elements in the graphics window.Select 3D Element Appears when Element Dimension is set to 3D. Available when the Group Reference check box is cleared.Lets you select 3D elements in the graphics window.ExcludedLets you exclude certain elements from selection.Note: If you select elements in the graphics window, be sure to select only elements of the appropriate type. For example, if Element Dimension is set to 1D and Element Type is set to CBEAM, you can select any 1D element, even if it is not a CBEAM element.If you select elements that are not the appropriate type, Simcenter Nastran might use unintended responses from other elements for which the response item code is still valid. |
| Limits | LowerSets the lowest acceptable value for the selected response.The unit of measure depends on the selected response. For example, for Frequency Response Displacement (FRDISP), you might specify the value in inches or millimeters. If necessary, the exporter converts the unit of measure to the one required by Simcenter Nastran.If Element Result is set to Item Code, the value uses the appropriate unit of measure for the model and the selected response.UpperSets the highest acceptable value for the selected response.Low End of FrequencyAppears when Frequency Math Function Type is set to anything other than Value.Sets the lower end of the frequency range.High End of FrequencyAppears when Frequency Math Function Type is set to anything other than Value.Sets the higher end of the frequency range.Note: If you do not want to specify a lower or upper limit, leave the corresponding box blank. If you type 0, the solver interprets that as the constraint value. |
| Card Name | Displays the names of the Simcenter Nastran bulk entries that will be generated when you solve the solution: DCONSTR and DRESP1. |
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Design Constraint - Direct Frequency dialog box, Simcenter 3D 2021.1 Series
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Source: https://docs.sw.siemens.com/en-US/doc/289054037/PL20200601120302950.advanced/xid1497559 · retrieved 2026-07-17