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Transcript of Advanced WB Techniques.pdf
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AdvancedANSYS Workbench
Techniques
Presented At
Midwest ANSYS User Group
Fall 2005 Meeting
By
Krishna S. Raichur
Belcan Engineering Group
Downers Grove, IL
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What is Workbench?
A unified working environment for:
Importing CAD geometry
Preparing models for analysis (DesignModeler)
Performing FEA simulations (Simulation) Optimizing designs (DesignXplorer or DesignXplorer
VT)
ANSYS Workbench
DesignModeler Simulation DesignXplorer
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What is Workbench?
Other modules included in Workbench:
Engineering Data a material data repository
FE Modeler to read and write NASTRAN and
ABAQUS models CFX-Mesh to prepare meshes for CFX-5
For most ANSYS users, Workbench is usually
synonymous with the Simulation module of
Workbench.
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What is Workbench?
The Simulation module in WB is built around core
ANSYS technology.
Not all ANSYS capabilities have been exposed yet in
Simulation, but it is certainly not a lightweightversion of ANSYS.
By using Commands objects, you can access virtually
any ANSYS feature.
This advanced use of Workbench is the focus of thispresentation.
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Why Use Workbench?
There are many compelling reasons to use WB.
Here are the top five:
Geometry Import
Tremendous savings in time CAD Associativity
Easy to make geometry changes, update the simulation, and
compare to previous scenario
Automatic Contact Detection Hundreds of contact pairs are detected within seconds!
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Simulation Work Flow
First step in learning the
use of commands in WB
is to understand the
overall work flow.
Pressing Solve button in
Simulation creates an
APDL input file, ds.dat,
in the solver working
directory. This is what enables the use
of commands.
Import
Geometry
Assign
Materials
Review/Modify
Contact Regions
MeshControls
Apply
Loads / BCs
Solve
Review
Results
Batch Solution
XMLResults File(s)
ds.dat
File
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The ds.dat File
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The ds.dat File
Contains preprocessing, solution, and postprocessing
commands.
Nodes
Elements
Materials
Contact Pairs
Loads
Postprocessing
Solution
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Commands Objects
You can have your own commands
included in ds.dat by inserting
Commands objects in the tree outline.
Geometry Branch
You can insert Commands for each part.
Useful if you want to:
Change element type or keyoptions
Change material properties
Change real constants (such as to add datafor composites)
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Commands Objects
Contact Branch
Insert Commands for each contact region.
Useful if you want to change or add contact
options not yet exposed in Simulation
(Keyopt(7), for example).
Mesh Branch
No Commands allowed
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Commands Objects
Solution Branch
Commands inserted here are placed
immediately after the /POST1 command.
Useful if you want to:
Postprocess analysis types not yet exposed inSimulation (PSD, response spectrum, etc.)
Add your own postprocessing, such as
unaveraged stress plots, path plots, and
surface operations
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Commands Objects
Input Arguments
Up to 9 input arguments are
allowed on all Commands
objects.
Values can be entered in theDetails region just like
other Workbench data.
ARG1-ARG9 can also be
flagged for parametric
studies just like any otherWorkbench input data.
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Commands Objects
Output Parameters
For Commands objects at
the Solution level,
Workbench scans for
parameters with a user-specified prefix (my_ by
default) and reports their
values in the Details region.
Can be flagged for
parametric studies just likeany other Workbench
output data.
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Named Selections
The ds.dat file contains no solid model
data, only nodes and elements.
Named Selections are useful to identify
entities when using commands.
Example: To apply a tabular (non-uniform) pressure
load on the highlighted area, we give the
area a name (InnerFace in this
example).
When Workbench creates ds.dat, it will
put all nodes on that area into a nodal
component called INNERFACE.
The commands to apply the tabular load
can then use this nodal component.
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Named Selections
Named solid bodies (volumes), surface bodies
(shells), and line bodies (beams) are written to
ds.dat as elementcomponents.
Named faces (areas), edges (lines), and vertices(keypoints) are written as nodal components.
By naming all entities required for command
processing, you can eliminate the need for solid
model data.
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Examples
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Ex 1: Custom Postprocessing
Requirement
Under a series of given
loads, calculate the
diameter at Spout_PtX
and the gap between spoutand base.
Solution
First create named
selections to identify the
desired points.
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Ex 1: Custom Postprocessing
Solution (contd)
In a Commands object
under Solution, use APDL
to retrieve displacements
and calculate the desireddata.
By using the my_ prefix,
the output parameters are
displayed in the Details
region, where they areflagged for a parametric
study.
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Ex 2: Tabular Loading
Requirement
Apply a tapered pressure
load on the inner face of a
tube and verify with a
pressure plot in thepostprocessor.
Solution
First create a named
selection to identify the
area.
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Ex 2: Tabular Loading
Solution (contd)
Use a Commands object in
the Environment branch to
create and apply a tabular
load.
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Ex 2: Tabular Loading
Solution (contd)
Use a postprocessing
Commands object (Solution
branch) to plot element
pressures and store the ploton a .png file.
The requested plot shows
under the Commands
branch as Post Output.
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Ex 3: Random Vibrations (PSD)
Requirement
Do a PSD analysis in
Workbench.
Solution
Create a named selection of
supports (required later in
PSD analysis).
Do a modal analysis
(required step for any
dynamic analysis).
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Ex 3: Random Vibrations (PSD)
Solution (contd)
Insert a Commands object
under Enviroment to obtain
PSD solution.
Notice the *ABBRcommand at the end of the
PSD input.
This disables the SOLVE
command in ds.dat, but
allows subsequent
postprocessing commands
to be executed.
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Ex 3: Random Vibrations (PSD)
Solution (contd)
Insert postprocessing
commands in the Solution
branch to plot 1 stresses
and displacements from thePSD analysis.
The SET command at the
end allows subsequent
modal postprocessing to be
completed.
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Questions?