Learning Forum

[martin.kopplow]

In my current design, I need to determine the position of the object's center of mass and moments to calculate the security against tipping in case of a side impact. 

This has worked well while I was in conceptual stage with still simple geometry. Now, I have added a lot of components and detail and among these, cosmetic threads. I need to re-calculate and check if I'm still within the limits given. It turns out the calculation of mass propierties now fails for every component that has cosmetic threads in it. Needless to say I cannot effort to delete them all, nor do I want to fork a set of data without them. 

I can just hide the cosmetic threads for the calculation to be successful. That is not exactly fine but a somewhat workable interim solution for a single part, but not for assemblies, since there are many, distributed all over the design.  

 

Question: Is this a known issue, and how to calculate the mass properties of an assembly in a straightforward manner when it has cosmetic threads and maybe other massless things in it?

 

Ideal solution: Select the component in question in the structure tree, hit Mass Properties button in Inspect ribbon tab and see mass properties of component and all it's sub components displayed after a few seconds. The application should be smart enough to know  things like threads, curves and open surfaces cannot have a volume, so no mass and consequently skip them. 

[Devendra Badgujar]

Hi Martin Kopplow

Let me check this and will get back to you soon.

[Devendra Badgujar]

Hi Martin Kopplow

Understanding you are trying this in SpaceClaim, this is a known issue and a bug has already been filed for this. 

Unfortunately, currently there is no fix for this and the only possible workaround for you, to display the mass properties for an assembly containing cosmetic threads, is to hide the cosmetic threads and other massless things in it. Thank you for your understanding.

Regards.

[martin.kopplow]

Hi Devendra Badgujar

Thanks for your answer. I kind of expected something like this and hope that bug will be resolved before long. In the meantime: What is the best method for hiding everything massless, given the solids may not all be named solids in the tree, so the structure tree search might probably not work reliably? 

[Devendra Badgujar]

Hi Martin Kopplow

Let me check with the team and will get back on this.

[Devendra Badgujar]

Hi Martin Kopplow Please check the attached video which demonstrates the method  for hiding everything massless.

? This post originally contained file attachments which have been removed in compliance with the updated Ansys Learning Forum Terms & Conditions

[martin.kopplow]

Thanks, I was not aware threads would be recognized as surface bodies. Will try this next time I need the mass properties and report back.