1. Chapter 6 Working with CAD
DesignModeler

2. Working with CAD Bodies and Parts Support for CAD Versions
Length Units
Attaching to a CAD Session
Importing CAD Files
Positioning Imports
Import Units
Exporting a Model
Creating Negative Geometry
Edge and Face Merge for Model Simplification
Automated Option for Ease of Use
Improved Cleanup and Repair of CAD 2

3. A. Bodies and Parts
DesignModeler is primarily intended to provide geometry to an analysis environment. For this reason we need to see how DM treats various geometries.
DesignModeler contains three different body types:
Solid body: Body has surface area and volume
Surface body: Body has surface area but no volume
Line body: Body consists entirely of edges, no area, no volume
By default, DM places each body into one part by itself
Individual parts will always be meshed separately
If bodies in separate parts share faces, the meshes on those shared faces will not be matched
Multiple bodies in a single part will have matched meshes on shared faces when meshed 3

4. Active and Frozen Bodies
By default, DM will merge new geometry with existing geometry to maintain a single body
This can be controlled by working with either frozen or active bodies
You can toggle between frozen and active states for using the Freeze and Unfreeze tools 4

5. Active and Frozen Bodies
There are two body states in DM:
Active:
Body can be modified by normal modeling operations (cannot be sliced)
Active bodies are displayed in blue in the Feature Tree View
Frozen: (Tools>Freeze)
Two Purposes:
Provides alternate method for Assembly Modeling
Provides ability to “Slice”
A Frozen body is immune to all modeling operations except slicing
To move all active bodies to the Frozen state, use the Freeze feature
To move individual bodies from the frozen to active, select the body and use the Unfreeze feature
Frozen bodies are displayed as transparent in the Tree View
Active
Frozen 5

6. …Bodies and Parts Body Suppression: Suppressed bodies are not plotted
Suppressed bodies are not sent to other Workbench modules for meshing or analysis, nor are they included in the model when exporting to a Parasolid (.x_t)
In the tree view an “X” is shown near suppressed bodies
Unsuppressed
Suppressed 6

7. … Bodies and Parts Parts:
By default, DesignModeler places each body into one part by itself
You can group bodies into parts
Multi-body parts contain multiple bodies (volumes), and have shared topology. The meshes on shared faces are matched
To form a new part, select two or more (or RMB “Select All”) bodies from the graphics screen and use >Tools>Form New Part
The Form New Part option is available only when bodies are selected and you are not in a feature creation or feature edit state 7

8. … Bodies and Parts Why multi-body parts? Example: DM Mesh DM
In DM: 3 parts, 3 bodies consisting of 3 solids
During Meshing: 3 solids, 3 bodies
Each solid meshed independently
Nodes are not shared
Nodes do not line-up
No connection between the 3 mesh regions for fluid flow and/or heat transfer
Can connect using a Grid Interface in FLUENT/CFX DM
Mesh DM 8

9. … Bodies and Parts Example (continued): DM Mesh DM
In DM: 1 part, 1 body consisting of 1 solid
During Meshing: 1 solid ,1body
Entire solid meshed as one entity
No internal surfaces DM
Mesh DM 9

10. … Bodies and Parts Example (continued): DM Mesh DM
In DM: 1 multi-body part, 3 bodies/solids
During Meshing:1 multi-body part, 3 bodies/solids
Each solid meshed independently but node connectivity among solids is preserved DM
Mesh DM 10

11. B. Support for CAD Versions
Reader and Plug-In support:
CAD interfaces are associative and require installation of CAD package
Autodesk Inventor 2008 (Windows 32-bit)
Autodesk Inventor 2009
CoCreate Modeling 2008
CoCreate Modeling - OneSpace Modeling 2007
Mechanical Desktop 2008 and 2009
Pro/Engineer WF 4 (Windows XP and Vista, 32-bit and 64-bit)
Pro/Engineer WF 3 (Windows XP 32-bit and 64-bit, Windows Vista 64-bit)
Solid Edge v19 and v20
SolidWorks 2008 and 2009
UG NX 5.0 and 6.0
64-bit support for all interfaces including IGES and STEP readers

12. …Support for CAD Versions
Plug-In support:
TeamCenter Engineering 2005 w/ NX5 and NX6 (Windows XP 32-bit and 64-bit)
Reader support:
ACIS (SAT) 19
CADNexus/CAPRI CAE Gateway CATIA V5 (R16 – R18) (Win XP 32-bit and 64-bit)
CADNexus/CAPRI CAE Gateway CATIA V5 (R18 SP4+) (Win XP 32-bit, 64-bit)
CATIA V4 (Windows 32-bit)
CATIA V5 (R2 - R19)
IGES 4.0, 5.2, 5.3
Parasolid 19.1
STEP AP203, AP214

13. C. Length Units
When a new DM session is started a dialog box allows selection of the desired length unit (can be set as default)
Units cannot be changed mid-session. 13

14. D. Attaching to a CAD Session
If a CAD session is currently open, this automatically imports the model into the DesignModeler session
File>Attach to Active CAD File
Maintains Bi-Directional associativity 14

15. … Attaching to a CAD Session
Bidirectional Refresh
Refresh the geometry using parameter values from either the source CAD package or from the CAD parameters in DesignModeler's Details View.
Controls the parameter name suffix allowed from CAD Package to WB.To allow all parameters (dimensions ) created inside the CAD package to come inside DM, remove DS in the Parameter Key location 15

16. E. Importing CAD Files File>Import External Geometry File… Cut
The “active” plane in DM controls placement for “assembly” modeling (multi-bodies).
Import type details: Add, Cut, Slice, etc…
Does not maintain associativity
Cut 16

17. F. Positioning Imports
Both Import and Attach have a “Base Plane” property
Specify the plane (orientation) in which the Import or Attach model is referenced…
When creating a new Import or Attach feature, the active plane is chosen as the Base Plane by default
Users select planes from the tree view or Plane pull-down list prior to import
Example:
XY chosen for first import
YZ plane for second import
Add material option chosen
The Base Plane for Imports and Attaches in all agdb files prior to this upgrade is XYPLANE 17

18. G. Import Units Set the desired length unit when DM starts
Some import types allow you to set the units via the import details (Prior to Generate)
DM then converts the model length units into the current unit system 18

19. H. Exporting a Model File>Export … IGES exporting:
When exporting the model to an IGES file, you have the option to export solids or just trimmed surfaces.
>Tools>Options 19

20. I. Creating Negative Geometry
In many cases, when you import a CAD file, it is a model for a solid part
You may be interested in the fluid region surrounding or enclosed by a solid part
You can by “taking the negative” of the solid part, construct the corresponding fluid region
You can construct the negative of a CAD model:
In the original CAD package
In DesignModeler, using enclosures, fills, and Boolean body operations such as cut and slice 20

21. … Creating Negative Geometry
Enclosure:
Creates surrounding region around bodies to facilitate simulation of field regions
CFD, EMAG, etc
Box, sphere, cylinder or user defined shapes can be employed
Cushion property allows the boundary extent to be specified (must be > 0)
Apply enclosure to all bodies or only selected targets
Merge property allows for automatic multi-body part creation
Ensures original part and enclosure will have nodal match up when meshed

22. … Creating Negative Geometry
Example:
Circuit board model
Cutaway view of enclosure
Enclosure created using box option

23. … Creating Negative Geometry
Fill:
Creates frozen bodies that fill interior voids such as holes
Works with active or frozen bodies
Works only with solid bodies
Useful in CFD applications for creating flow volumes
Two Methods for Fill operation
By Cavity
By Caps

24. … Creating Negative Geometry
Example: Fill by Cavity
Goal is to model the interior (fluid region) of the valve block shown here
The desired (37) interior faces are selected then the Fill is inserted by clicking Generate

25. … Creating Negative Geometry
Example Fill by Cavity (cont.):
Resulting fill is a frozen (meshable) body
Interior region, now isolated, can be taken to the Mesher for meshing

26. … Creating Negative Geometry
Example: Fill by Caps
Goal is to model the interior (fluid region) of the hollow pipe shown here
Steps:
Create surfaces and close both ends of the pipe.
Use > Concept > Surfaces from Edges to create the end surfaces
Use Fill by Caps to create the interior flow region

27. … Creating Negative Geometry
Example Fill by Caps (cont.): 2 1
Closed End surface 3

28. … Creating Negative Geometry
Example Fill by Caps (cont.): 2 1
Interior Fluid Body Created

29. J. Edge and Face Merge for Model Simplification
Merge edges and faces based on angle criteria to simplify the model

30. K. Automated Option for Ease of Use
RMB
Clusters are displayed for preview
Option to edit clusters before merge
RMB

31. L. Improved Cleanup and Repair of CAD