Create or edit a substructure generation procedure
-
Display the Edit Step dialog box following the
procedure outlined in
Creating a step
(Procedure type:
Linear perturbation;
Substructure generation ), or
Editing a step.
-
On the Basic, Options, and
Damping tabbed pages, configure settings such as
substructure generation options and damping specifications.
Configure settings on the Basic tabbed page
-
In the Edit Step dialog box, display the
Basic tabbed page.
(For information on displaying the Edit Step
dialog box, see
Creating a step,
or
Editing a step.)
-
In the Description field, enter a short
description of the analysis step.
Abaqus
stores the text that you enter in the output database, and the text is
displayed in the state block by the Visualization module.
-
In the Substructure identifier field, enter an
integer between 1 and 9999 that uniquely identifies this substructure in your
model.
Abaqus
prepends a Z to the number you specify when it stores the
substructure identifier in the model database.
-
If desired, toggle on Evaluate recovery matrix
for to enable selective recovery in your analysis, and do one the
following:
-
Select Whole model to enable selective
recovery for the entire model.
-
Select Region, and select a node set or
element set from the list to enable selective recovery for a single set in your
model.
Configure settings on the Options tabbed
page
-
In the Edit Step dialog box, display the
Options tabbed page.
(For information on displaying the Edit Step
dialog box, see
Creating a step,
or
Editing a step.)
-
From the Generation Options, do any of the
following:
-
Toggle on Compute gravity load vectors to
calculate the substructure's gravity load vectors during substructure
generation.
-
Toggle on Compute reduced mass matrix to
generate a reduced mass matrix for the substructure.
-
Toggle on Compute reduced structural damping
matrix to generate a reduced structural damping matrix for the
substructure.
-
Toggle on Compute reduced viscous damping
matrix to generate a reduced viscous damping matrix for the
substructure.
-
Toggle on Evaluate frequency-dependent properties at
frequency to evaluate frequency-dependent material properties in
substructure generation. If you toggle on this option, you can also specify the
custom frequency for the frequency-dependent properties.
-
If you want to specify retained eigenmodes for generation of a coupled
acoustic-structural substructure, toggle on Specify retained
eigenmodes by, then select either Mode range or
Frequency range.
-
If you are specifying retained eigenmodes by mode range, enter the
following data in the Data table to generate the list of
eigenmodes:
- Start Mode
-
The first mode number.
- End
Mode
-
The end mode number.
- Increment
-
The increment in mode numbers between the start and end modes.
For detailed information on how to enter data, see
Entering tabular data.
-
If you are specifying retained eigenmodes by frequency range, enter
the following data in the Data table:
- Lower
Frequency
-
The lower limit of the frequency range or a single frequency, in
cycles/time.
- Upper
Frequency
-
The upper limit of the frequency range, in cycles/time.
For detailed information on how to enter data, see
Entering tabular data.
Configure settings on the Damping tabbed
page
-
In the Edit Step dialog box, display the
Damping tabbed page.
(For information on displaying the Edit Step
dialog box, see
Creating a step,
or
Editing a step.)
-
From the Global Damping Ratios options, specify
the Field to which global damping will apply in this step:
-
Choose None to exclude the effects of global
damping.
-
Choose All to apply global damping to all of
the displacement, rotation, and acoustic fields in a model.
-
Choose Acoustic to apply global damping only
to the acoustic fields in a model.
-
Choose Mechanical to apply global damping
only to the displacement and rotation fields in a model.
-
If you selected any Field setting other than
None, do any of the following:
-
For the Alpha option, specify a value for the
first Rayleigh damping ratio.
-
For the Beta option, specify a value for the
second Rayleigh damping ratio.
-
For the Structural option, specify a value
for the structural damping ratio.
-
From the Viscous damping options, choose one of
the following:
-
Choose None to exclude the effects of viscous
damping altogether at the usage level.
-
Choose Element to activate only the generated
condensed viscous damping matrix of the substructure.
-
Choose Factor to activate only the Rayleigh
viscous damping.
-
Choose Combined to activate the combined
generated and Rayleigh viscous damping matrix.
-
From the Structural damping options, choose one
of the following:
-
Choose None to exclude the structural damping
matrix.
-
Choose Element to activate only the generated
condensed structural damping matrix of the substructure.
-
Choose Factor to activate only the stiffness
proportional structural damping matrix.
-
Choose Combined to activate the combined
generated and stiffness proportional.
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When you have finished configuring settings for the substructure
generation step, click OK to close the Edit
Step dialog box.
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