CAD

1
CAD Parameters

• Chapter Nine

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

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

4
DesignModeler CAD

• DesignModeler is a Workbench module allowing
  users to create or prepare models for use in
  Simulation

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.

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

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

Model shown is from a sample Inventor assembly.
8
Controlling CAD Settings

• To change default behavior, go to Tools menu gt
  Common Settings Geometry Import to change
  default behavior
• Options dialog box also accessible from
  Workbench Start page in lower-left corner.

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
  toimport 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

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)

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

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
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

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

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

16
CAD Associativity

• CAD associativity allows updating theCAD
  geometry in Simulation without needing to
  redefine material properties, loads, supports,
  and results
• Slide 3 showed CAD systems which areassociative
  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.

17
Save Updated Model (Reader Mode)

• Reader mode is when a model is attachedin
  Simulation without the CAD system being started
  up first
• For Unigraphics, if the part is updated inreader
  mode, the updated file can be saved
• This is used in conjunction with parametersto
  update the UG model with new dimensions

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

19
Attach File via Temp File

• For large models, it may be advisable toturn
  this feature on.
• When attaching large models, a temporaryfile to
  facilitate import can be created/deletedby
  Simulation if this option is set
• If set to Yes, a location for the
  temporarydirectory can be specified by the user

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.

21
Parameter Import

• Dimensions of CAD features can beimported into
  Simulation
• By turning on this feature (default),
  anydimension with the user-defined prefix
  orsuffix (default is DS) will be imported into
  Simulation as a parameter
• Only dimensions for features will be imported
• Once imported, the parameters of
  variousdimensions will appear in the Details
  viewfor that particular part.
• The use of parameters to change theCAD model or
  to set up parametric studieswill be covered in
  detail in the next section

22
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 gt Design Variables and
  define parameter name. Then change dimension to
  parameter via Edit Dimensions

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.
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 gt Setup Material gt
  Define/Assign
• Unigraphics Tools gt Material Properties
• Inventor (to define materials) Format gt
  MaterialsInventor (to assign) right-click part
  Properties Physical tab

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 levelwill 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

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 gt Model Datum gt Coordinate
  System
• SolidWorks Insert gt Reference Geometry gt
  Coordinate System

27
Named Selections Import

• If groups are defined in the CAD package,these
  can be brought into Simulation asNamed
  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

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

29
Named Selections Import

• Each CAD system has different ways to rename
  geometric entities, so please refer to the CAD
  documentation
• DesignModeler Tools gt Named Selections
• Pro/ENGINEER Edit gt Setup Name gt Other
• Unigraphics select entities, right-click
  Properties

30
CAD Attribute Import

• The CAD Attribute Import capability canbe used
  to import attribute information from CAD
  software, including motion loads
• For example, if a CAD system uses a supported
  kinematics program, the motionloads 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.

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
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 andthen resolve the
  model.
• Usually, it is a good idea to rename thebranches
  in the Outline tree to distinguishbetween the
  duplicated branches

33
Multiple Design Studies

• After duplicating the branch and resolving, the
  HTML Report will also contain all the cases solved

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 gt Update Use Geometry
  ParameterValues from the Context toolbar
• This will work only for CAD systems whichare
  associative. After performing the abovesteps,
  the geometry for the selected branchwill be
  updated, and so will all materials,contact
  regions, and loads.

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

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

37
Sending Parameters and Updating

• The CAD parameters may be changed in the Details
  view. Then, select Update gt 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 dimensionsmust be such
  that a valid geometrycan be created in the CAD
  software.If not, the update will not succeed.

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.

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

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

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.

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

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

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)

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

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

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)

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

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.

50
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