1. Chapter Nine
CAD & Parameters
IGES import log file

2. Chapter Overview
In this chapter, interoperability with CAD software as well as parameters will be discussed.
The following will be covered:
CAD Interoperability
Multiple Design Studies
Parameter Manager
The capabilities described in this section are generally applicable to all ANSYS licenses. However, some CAD functionality are specific to certain CAD software, so these will be designated accordingly.
Not all CAD software have the same features, so there are some differences in CAD-related functionality which is supported in Simulation
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3. A. CAD Interoperability
As noted in Chapter 1, the following Geometry Interfaces are supported in Simulation:
The Geometry Interface license can be run in reader mode for all licenses. The Geometry Interface can be run in plug-in mode for the CAD software listed under “Associative”
Detailed CAD support listing in Simulation online help
IGES Geometry Interface reader is free
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4. … DesignModeler & CAD
DesignModeler is a Workbench module allowing users to create or prepare models for use in Simulation
DesignModeler has a similar look and feel to Simulation
DesignModeler can be used to create geometry in lieu of other CAD software
DesignModeler can also read in parts and assemblies from the same CAD sources as Simulation. These models can be prepared and modified for analysis, then attached in Simulation
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5. … CAD Interoperability
There are various items which can be brought in from supported CAD systems when models are attached:
Geometry import
Spot weld import
Parameter import
Material property import
Coordinate system import
Named selection import
Motion loads import
CAD attribute processing
There are three ways of setting import preferences when attaching CAD geometry.
Three methods – one through the Workbench Projects page, another in Simulation Geometry branch, the third in Options… box – will be discussed next.
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6. … Controlling CAD Settings
When importing models in Workbench Project page, the left side controls various CAD-related settings
These settings only affect the existing model
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7. … Controlling CAD Settings
On the other hand, after a model is already imported into Simulation, CAD-related settings can be changed under the Geometry branch
These settings only affect the existing model
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Model shown is from a sample Inventor assembly.

8. … Controlling CAD Settings
To change default behavior, go to “Tools menu > Common Settings: Geometry Import” to change default behavior
“Options” dialog box also accessible from Workbench Start page in lower-left corner.
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9. … Geometry Import
For CAD-related settings, importing solid, surface, or line bodies is available
One cannot import a part with mixed solids and surfaces.
Assemblies with mixed solids and surfaces are OK.
In other situations, users may wish only to import a particular entity type to ignore unnecessary or construction geometry present in the model
Hence, toggling import of solids, surfaces, and/or line bodies is possible
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10. … Geometry Import (Solid Bodies)
Import of solid bodies is supported for all CAD systems
Contact regions will automatically be detected between parts in an assembly.
Note that the CAD mating relationship information is not used
Slider controls contact detection tolerance (in ANSYS Professional licenses and above, user can specify value in length units)
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Model shown is from a sample SolidWorks assembly.

11. … Geometry Import (Solid Bodies)
DesignModeler has concept of “multi-body parts”
A multi-body part is a group of solid bodies. Instead of using different mesh and contact regions between solid bodies, the bodies within a part will share nodes at common interfaces
Individual Bodies (non-matching mesh)
Single Part (matching mesh)
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12. … Geometry Import (2D Solid Bodies)
Before importing 2D geometry you must specify “Analysis Type” is “2D” in the Advanced Geometry options
Once imported, the 2D details can be specified from the Part branch. Plane stress, plane strain or axisymmetric
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13. … Geometry Import (Surface Bodies)
Simulation also supports import of surface bodies from most CAD systems
For ANSYS Professional licenses and above, surface body contact is available from the Contact branch
Spot weld definitions can also be used for surface assemblies
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14. … Geometry Import (Surface Bodies)
In DesignModeler, “joints” can be used to merge surface bodies together to a “part”
Instead of using spot welds or edge contact, “joints” in DesignModeler can ensure that surface bodies share nodes
Surfaces that share edges can also form a part to share nodes
Individual Bodies (non-matching mesh)
Part of Surface Bodies (matching mesh)
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15. … Geometry Import (Line Bodies)
Line bodies can be imported from DesignModeler only
Line bodies require cross-section definition and orientation, which only DesignModeler supplies
Line bodies are meshed with beam/link elements
Line bodies can be used in conjunction with surface bodies
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16. … CAD Associativity
CAD associativity allows updating the CAD geometry in Simulation without needing to redefine material properties, loads, supports, and results
Slide 3 showed CAD systems which are associative in Simulation
In some cases, for very large models, the processing time may take a while, so the user can turn off the CAD associativity feature to allow for faster attaching
Turning this feature off will make import faster but will not allow updating of the CAD geometry if changes to the CAD model are made
It is generally not recommended to turn this off unless the user does not need associativity
Although the toggle is not available for DM and ProE, this does not mean that these systems do not support associativity. DM and ProE support associativity, just not the ability to toggle associativity off.
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17. … Save Updated Model (Reader Mode)
Reader mode is when a model is attached in Simulation without the CAD system being started up first
For Unigraphics, if the part is updated in reader mode, the updated file can be saved
This is used in conjunction with parameters to update the UG model with new dimensions
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18. … Do Smart Update
“Smart Update” is a method by which the updating of assemblies is sped up if the assembly contains unmodified components.
Currently, only Inventor and Unigraphics support “Smart Update” feature
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19. … Attach File via Temp File
For large models, it may be advisable to turn this feature on.
When attaching large models, a temporary file to facilitate import can be created/deleted by Simulation if this option is set
If set to “Yes”, a location for the temporary directory can be specified by the user
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20. … Spot Weld Import Spot welds can be used for surface assemblies
Although Simulation has some limited spot weld definition capabilities (at vertices only), spot welds can be defined more easily in DesignModeler and Unigraphics and then imported into Simulation.
Not all CAD software support spot weld definitions in a manner usable by Simulation
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21. … Parameter Import
Dimensions of CAD features can be imported into Simulation
By turning on this feature (default), any dimension with the user-defined prefix or suffix (default is “DS”) will be imported into Simulation as a parameter
Only dimensions for features will be imported
Once imported, the parameters of various dimensions will appear in the Details view for that particular part.
The use of parameters to change the CAD model or to set up parametric studies will be covered in detail in the next section
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22. Sample dialog boxes to change dimension name in CAD software
… Parameter Import
Each CAD software has different ways to change the dimension name, so please refer to the CAD documentation
DesignModeler: checkmark the dimension, provide Parameter name
Pro/ENGINEER: select dimension, right-click “Properties”
Unigraphics: select dimension and “Edit”
SolidWorks: select dimension, right-click “Properties”
Inventor: select dimension, right-click “Dimension Properties”
Solid Edge: select dimension, right-click “Edit Formula,” change name
Mechanical Desktop: “Part > Design Variables” and define parameter name. Then change dimension to parameter via “Edit Dimensions”
Sample dialog boxes to change dimension name in CAD software
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23. … Material Property Import
If “Material Properties Transfer” is enabled, material properties, if defined, will be imported from supported CAD systems
The following properties will be imported:
Note that Simulation will not import UG properties in table form (such as temperature-dependent data)
If the material type is changed in CAD, this will be reflected in an update. However, if the values of the material property change in CAD, this will not update to prevent overwriting of user-defined values in Simulation.
Not all CAD software support all material property definition which Simulation supports.
Materials imported from CAD will appear in “Engineering Data” branch and will be assigned correctly to parts.
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24. … Material Property Import
Each CAD system has different ways to define and assign materials, so please refer to the CAD documentation
DesignModeler: will import materials from ProE, UG, Inventor, but user cannot define material properties inside of DM directly
Pro/ENGINEER: “Edit > Setup: Material > Define/Assign”
Unigraphics: “Tools > Material Properties”
Inventor (to define materials): “Format > Materials” Inventor (to assign): right-click part “Properties: Physical tab”
Sample dialog boxes to assign/define material properties in CAD software
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25. … Coordinate System Import
Coordinate systems are used in Simulation to apply directional loads or results postprocessing
Coordinate systems allow users to define the orientation for direction-dependent loads or contour results
Simulation supports importing of local coordinate systems from some CAD systems
User-defined CS on part or assembly level will be imported
In DM and SW, names come through as-is. In ProE, name comes through as part name, followed by CS name in square brackets
Modified/added CS are updated with model
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26. … Coordinate System Import
Each CAD system has different ways to define coordinate systems, so please refer to the CAD documentation
DesignModeler: create Plane, Details view: Export CS
Pro/ENGINEER: “Insert > Model Datum > Coordinate System”
SolidWorks: “Insert > Reference Geometry > Coordinate System”
Sample dialog boxes to define coordinate systems in CAD software
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27. … Named Selections Import
If “groups” are defined in the CAD package, these can be brought into Simulation as Named Selections for supported systems. This makes it easier to assign mesh controls or apply loads to entities.
Named selections import can be enabled, as shown on the right
If the “group” in the CAD software has the specified prefix (default is “NS”), then it is imported in the Named Selection branch of Simulation
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28. … Named Selections Import
However, note that this Named Selection processing feature is related to CAD API functionality.
Unless the CAD system allows direct manipulation of the entities, simply providing ‘names’ for geometric entities will not be imported into Simulation.
Interfacing with CAD API via VB or similar scripting languages may be required
Currently, only Pro/ENGINEER and Unigraphics (and DesignModeler) allow users to ‘rename’ geometric entities such as surfaces.
Pro/ENGINEER only allows one entity per named selection (limited usefulness)
Unigraphics allows for multiple names per named selection, so ‘true’ groups can be created
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29. … Named Selections Import
Each CAD system has different ways to rename geometric entities, so please refer to the CAD documentation
DesignModeler: “Tools > Named Selections”
Pro/ENGINEER: “Edit > Setup: Name > Other”
Unigraphics: select entities, right-click “Properties”
Sample dialog boxes to create “named selections” in CAD software
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30. … CAD Attribute Import
The CAD Attribute Import capability can be used to import attribute information from CAD software, including motion loads
For example, if a CAD system uses a supported kinematics program, the motion loads can be imported into Simulation for subsequent stress analyses
If this feature is turned on, the prefix can be specified. Only attributes with the given prefix (default is “SDFEA” or “DDM”) will be imported into Simulation.
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31. B. Multiple Design Studies
In many situations, users may wish to perform comparisons of different load cases or even different types of analyses
Copying branches in the Outline Tree allow users to easily compare different Environments or even different Models
One may wish to compare the results of two different load cases, as shown here
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32. … Multiple Design Studies
To solve different cases, simply duplicate the parent branch
Duplicate the Environment branch when the user is:
Solving multiple load cases
Solving different types of analyses (static, modal, etc.)
Duplicate the Model branch when the user is:
Comparing different material properties
Comparing different geometry configurations
Comparing different contact conditions
Comparing different mesh densities
After duplicating the appropriate branch, simply make the necessary changes and then resolve the model.
Usually, it is a good idea to rename the branches in the Outline tree to distinguish between the duplicated branches
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33. … Multiple Design Studies
After duplicating the branch and resolving, the HTML Report will also contain all the cases solved
Select which branches you want to include in the HTML Report prior to generating it.
All input, results, and figures will be included for each branch and labeled appropriately.
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34. … Updating Geometry
For the aforementioned cases, changing the duplicate branch is straightforward
For example, to compare two different loading conditions, duplicate the Environment branch, then redefine or add/delete any loads or supports, as needed.
However, when dealing with multiple geometry configurations, additional steps are required
Make changes to geometry in the CAD system
Duplicate the Model branch
Select the Geometry branch, then choose “Geometry > Update: Use Geometry Parameter Values” from the Context toolbar
This will work only for CAD systems which are associative. After performing the above steps, the geometry for the selected branch will be updated, and so will all materials, contact regions, and loads.
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35. … Updating Geometry Example
For example, in the model below, geometry changes were made in the CAD software.
The Model branch was duplicated to “Model 2”
“Model 2” was selected and the new geometry was updated
All material assignment, mesh controls, (contact regions), and loads and supports were updated without manual intervention
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36. … Sending Parameters and Updating
The method just described is an easy way to perform comparisons of different geometry configurations
Another way of updating the geometry is to do this from within Simulation
Recall from Section A “Parameter Import” of this chapter that dimensions with a user-defined prefix or suffix (default is “DS”) will import to Simulation as a parameter
If this is performed, each part will have its parameters (i.e., dimensions) shown in the Details view
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37. … Sending Parameters and Updating
The CAD parameters may be changed in the Details view. Then, select “Update > Update: Use Simulation Parameter Values” from the Context toolbar, and Simulation will update the CAD geometry for that Model branch
Simulation actually sends the parameters to the CAD software, which regenerates the new model and sends it back to Simulation automatically
Note that the changes in dimensions must be such that a valid geometry can be created in the CAD software. If not, the update will not succeed.
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38. … Updating Geometry Notes
It is important to note the following when updating geometry from the CAD system
Only supported CAD systems (noted in the table below) have this feature. The CAD software must be installed locally on the same machine since Simulation uses the CAD API.
If the topology changes, some entity assignments (e.g., loading on a surface) may need to be redefined since the original item (such as a surface) is redefined.
If the topology changes, this results in the associativity being broken for that topology. This will be indicated with a “?” in the Outline Tree after an update.
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39. … Updating Geometry Notes
Important points to keep in mind (continued):
All loads will have the same values as before, even if volumes, surfaces, or edges change in volume, area, or length:
The magnitude of all loads will remain constant. For example:
If force was applied on a surface and the surface area increased, the force magnitude remains the same but results in the force per unit area decreasing
If pressure was applied on a surface and the surface area increased, the pressure value remains the same, but this results in more force overall being applied on the surface
The orientation of loads will not change, either
For structural loads, if a direction is specified using existing geometry, the direction of the load will not change even though the geometry used for load orientation has changed
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40. … Multiple Design Studies
Performing multiple design studies does not require that the Environment or Model branch be duplicated.
It is possible to insert a blank, new Environment branch from the Model branch
After inserting a new Environment branch, this branch will be blank.
Apply loads and request results, as desired
It is also possible to insert a completely different model in the same Simulation database
Go to the Workbench Project page.
Select the topmost project, the link to the “Active CAD Geometry” or to a “Geometry File.”
Use “Create a new Simulation” to bring in the model into the current Simulation database.
Set up analysis as usual
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41. … Multiple Design Studies
To solve multiple branches at once, go to the parent branch and click on the Solve button
For example, if a user wants to only solve a single Environment, select that Environment branch from the Outline Tree and click on the Solve button
To solve all Environment or Model branches, select the parent branch and click on the Solve button. All child branches will then be solved sequentially.
To solve multiple Environment or Model branches, Ctrl-select the branches of interest, then click on the Solve button.
The active branch currently being solved will be indicated with a green lightning bolt.
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42. C. Parameter Manager
Performing multiple design studies by duplicating the Model or Environment branch is an easy way to compare results
In the case of multiple Model branches, the Simulation database will become large because the mesh and results for each Model branch will be stored
For many cases, this may be a tedious, manual method
In some situations where many cases are being examined, the use of the Parameter Manager may be warranted
The Parameter Manager is useful to see the effect changes of input values have on certain output quantities. This is done in tabular form.
The Parameter Manager is not useful if the user needs to keep contour results, such as mode shapes of different geometries
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43. … Understanding Parameters
In Simulation, input and output parameters are used with the Parameter Manager
If a white input text entry in the Details view has a square next to it, it can be used as an input parameter
If a grey informative text entry in the Details view has a square next to it, it can be used as an output parameter
Simply select the square. A blue “P” will appear, indicating that this will be used with the Parameter Manager
Any items without a square cannot be used as a parameter. Moreover, any items not selected with a blue “P” will also not be used by the Parameter Manager
Example of input parameters
Example of output parameters
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44. … Using the Parameter Manager
To activate the Parameter Manager:
Browse through the Outline tree and activate any input parameters which will be used (add blue “P”)
Browse through the Solution branch with results and activate any output parameters to be used (add blue “P”)
Use of Results Scoping (covered in Chapter 9) allows the user to query the local results. For example, by scoping results on selected surfaces, the max equivalent stress on the surfaces can be used as an output parameter
Select the Solution branch of the Environment of interest and select the Parameter Manager button
The Parameter Manager worksheet will appear (see next slide)
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45. … Using the Parameter Manager
The Parameter Manager worksheet tab shows the defined input and output parameters under “Definitions”
The “Scenarios” is a table of cases which will be run
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46. … Using the Parameter Manager
Each “Scenario” is a simulation which will be run
Under “Scenarios,” simply right-click to add rows
Each row represents a simulation
White input values can be changed to desired values
The grey output parameters reflect the result values
The last column indicates whether the solution has been performed. The types of status indicators are “Done,” “Ready,” and “Obsolete”
The row in bold is what is reflected in the Outline tree
Unlike the Multiple Studies method, the Parameter Manager does not store all results for all cases. The Outline tree will only reflect the last case (bold).
Check items which you want Parameter Manager to solve
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47. … Using the Parameter Manager
After setting up the scenarios and clicking on the Solve button, the Parameter Manager will sequentially solve each check-marked case
If CAD parameters are present, ensure that the dimensions result in valid geometry
If any errors are encountered, the Parameter Manager will skip that scenario
After completed, the results for each scenario can be compared easily in the table.
The results can be exported to Excel (right-click on Parameter Manager branch in Outline tree to export)
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48. … DesignXplorer and Parameters
DesignXplorer and DesignXplorer VT are Workbench modules allowing users to obtain a full understanding of the relationship between input and output parameters
DesignXplorer and DesignXplorer VT can be used to examine the effect input parameters have on output parameters.
After running the analysis, through XY graphs, response surface plots, sensitivity pie charts, and spider plots, the user can get a better understanding of which parameters affect certain output and by what degree.
This extends the use of parameters far beyond what is possible with the Parameter Manager.
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49. D. Workshop 9 Workshop 9 – Parameter Manager Goal:
Use the Parameter Manager to specify changes to the load magnitude and material properties of the model shown below and solve all scenarios at one time.
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