DesignModeler-Working with CAD

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

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

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

? 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

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

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

? Why multi-body parts?

? Example:

– 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

Example (continued):

– In DM: 1 part, 1 body consisting of 1 solid

– During Meshing: 1 solid ,1body

– Entire solid meshed as one entity

No internal surfaces

Example (continued):

– 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

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