Learning Forum

[AR]

Hi,

It has happened to me many times that I have a fully defined model (materials, mesh, contacts, etc.) and I need to make a change to a part of the geometry. I go to SpaceClaim, make the modification, and return to Workbench. I double-click on the model and click "Yes" when asked if I want to update the model. Sometimes it does it correctly, but other times it interprets that I have modified or added a lot of parts instead of the single part I changed. It messes up the parts I had previously grouped in folders in the geometry section, loses the contacts (I have disabled automatic generation), and even loses the mesh.

Why does this happen? Is there any way to fix it?

P.S. I am using Ansys 2021 R1.

Regards

[Kaushal Vadnere]

Hi

In workbench, right click on geometry cell and click on properties. In the properties pane, there is an option called 'Compare Parts on Update' under Advanced Geometry Options. By default it is set to NO, change that to 'associatively'. The option compares the existing geometry and updated-to geometry to determine if any bodies/parts remain unmodified. When you choose the Refresh Geometry context menu option (right-click the Geometry tree object or anywhere in the Geometry window), if no changes to the body are detected (found to be unmodified), then the body/part does not need to be remeshed after the update has occurred. 
Also, make sure that Smart CAD Update is also checked.

Refer to this article in Ansys help: Compare Parts on Update (ansys.com)

[mjmiddle]

Internal IDs are assigned to vertices, edges, faces, bodies and these need to stay the same for scopings to be kept in Mechanical. Making topological changes to any body will cause these IDs to change and likely all scopings to that particular body will need to be reselected in Mechanical. Additionally, it uses the hierarchy of component names and placement of the body in the ID naming convention, so moving bodies to different components will also require a rescoping to geometry on those bodies in Mechanical. So to be safe, at least do not drag bodies to different components. However, shared topology changes everything since it imprints edges and faces to adjacent bodies. So topological changes to a body can expect to also change IDs to any connected bodies by shared topology. In summary, it is hard to make topological changes to bodies and not expect to rescope geometry in Mechanical. This is typically what must be done. In Mechanical, there is a scoping wizard in the selection ribbon that remembers the previous entity for scopings and will alert you to changes when geometry is refreshed. This helps you locate the problems and guides in what needs to be reselected.

[AR]

Thanks for the two comments.

Switching to "Associative" in the advanced options of Geometry seems to work quite well.

As for the "scoping wizard", I have Ansys 2021, so I don't have that option. However, I have seen that option in a colleague's Ansys and it saves a lot of time to re-do the connections of each piece.

Thanks for everything. Regards