Challenge

Week 3 - Geometry simplification of an Electronic enclosure assembly

SSagar Vekariya27 Oct 2022

Aim:

The objective of the project is to convert CAD shapes into Icepak primitive shapes in Spaceclaim & modify the components in Icepak & define the correct physics.

Steps:

The given CAD model of an electronic enclosure assembly is imported in SpaceClaim where the following steps are carried out:

The bodies which have no effect on the focus bodies are removed from the geometry.
Using Icepak commands, the CAD shapes in the geometry are converted into Icepak primitive shapes.

Types of bodies:

Focus bodies - The bodies which will emit some heat or obstruct the flow of the system.

Necessary bodies - The bodies which will have some effects on the focus bodies.

Peripheral bodies - These bodies may or may not affect the focus bodies.

Dispensable bodies - The small bodies on the assembly which has no effect on the physics of the system, these bodies are completely neglected.

Geometry simplification:

The geometry required for performing thermal analysis using Icepak can often be directly prepared in Icepak. However, in some cases, the designer may choose some other CAD software to prepare the geometry. In such cases, the CAD geometry must first be converted into primitive Icepak shapes using the commands available in SpaceClaim.

Open the workbench and go to the components system and double-click on geometry

Now right-click on geometry and import the required CAD model, Now double clicking the geometry opens the SpaceClaim

The screw and washer which are used for connecting have no effect on the physics so these bodies are deleted first.

To delete all the screws, right on the screw, now click on locate in the structure tree and select all screws having the same name and delete

Tools used

Split body - The split body is used to separate a single body into two or delete the uncessary parts from the body. The plane of separation or the face must be chosen for the body separation.

The extra edges is deleted using cut command in split body

Delete Curvature - The curvature are used to increase the strength of the body which has no effect on flow or thermal analysis & these surface create complexity during the mesh which affect the final solution. Select the fillet & click on selection on the left column which finds all the similar fillet edges & these are deleted using the delete option.

To Delete the rounds / chamfers

we can delete all rounds at a time by clicking the the round and going the selection as shown in the figure

Now delete the rounds , some cases rounds can't be deleted all at once then select the rounds individually and delete them.

Roundness of geometry enclosure is selected and deleted as shown in the figure

Fill gaps - This option is used to fill gaps around the screws & connector as they are dispensable bodies for our analysis.

The geometry is then simplified into Icepak Objects using the Icepak Simplify command with Level 2 (polygon fit) simplification. The image attached below shows the bottom cover geometry simplified into Icepak Objects.

The part corresponding to PCB + electronic components is opened in a separate design window. The image attached below shows the part.

The following steps are used to simplify the CAD geometry (shown above) into Icepak Objects:

This part is divided into multiple parts by using the Split Body command with the top and bottom planes of the PCB. This separates most of the components from each other.

Identify Objects command is used to identify and convert CAD geometries of the bodies into Icepak Objects. The image attached below shows the different parts identified for conversion to Icepak Objects. (The parts are highlighted in red)

The remaining "Non-Icepak Bodies" are shown in the figure attached below.

The PCB is simplified into Icepak Object using the Icepak Simplify command with Level 1 (cuboid, cylinder fit) simplification. The remaining "Non-Icepak Bodies" are shown below.

The remaining "Non-Icepak Bodies" are simplified using Level 1 (cuboid, cylinder fit) or Level 2 (polygon fit) simplification. Some of the bodies are separated into multiple bodies using the Split Body command and selecting appropriate planes. The images attached below show some of the bodies before and after simplification.