I’m getting this error: Non-positive jacobian. Degenerated/distorted elements or bad face orientation in the mesh.
Apparently the mesh is not nice so I want to look at the mesh quality and then add some refinements, but I can’t find how to do that. Can anyone help me out? Much appreciated!
The project is here:
You can find the error by going to Simulation designer and selecting the to-92-heatsink simulation, where both runs failed.
Hi @wvisser,
can you somehow modify the geometry trying to avoid the issue as depicted in the picture:
This holds for both components inside your mesh. Please get rid of this and re-mesh your geometry.
Usually this fixes the problem. If not, please contact me again.
Good luck!
Jousef
Thanks for the speedy response! I don’t really grasp yet what the issue is. The top of the semi-round part is red but I don’t know what that means and what I can do about it.
I have an additional question (which was my original question), is there a way for me to view the red parts of the mesh like what you’re doing right now?
My pleasure @wvisser.
Could you just delete one “layer” of your two components. That is what I meant.
Can you send me your original model via Email? Contact me privately if you like.
Regarding your question there are several approaches:
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You can navigate through the right tree. By clicking on the eye symbol you can hide components.
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The other way is to click on the component(s) and right-click selecting Isolate selection
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You can also work with the Invert Selection mode which is quite useful in some cases
Does that somehow covers your question? Maybe I did not get you here.
Make sure you do not forget to send me your CAD model via Email. I will have a look at it and try to mesh it properly.
Cheers,
Jousef
I don’t know what a ‘layer’ is, could you explain that to me? Also, what exactly about these selected parts seems to be the problem? And I thought the red part was some feature to find low quality mesh parts, but it is just a selection, my bad.
The model is here: the ‘to-92-heatsink’ tab, which is the assembly containing 3 parts:
Again, thanks for the help!
Hi @wvisser!
Ah alright, I see. No - sorry if that somehow gave you the illusion that there would be a hidden option.
Thank you very much for your model. As I saw your “Block” already contains the transistor as well as the heatsink. What I have done now is:
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Export only the block as an IGES file
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Import into your workbench by selecting the file from your computer
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Mesh the geometry
That should help getting rid of the non-positive Jacobian caused by zero or negative volume.
Please keep me up-to-date if that fixes your problems. If so, please also adapt the other models you have.
Good luck!
Jousef