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Shell Geometry is Very Large?

James Parkus

Hello,

I recently made some updates to my ACAR templates in which I added many clearance and new contact definitions (about 15 clearances, 15 contacts). The contact definitions are not really new, but I changed them a bit. Now when I try to Submit a General Actuation Analysis (Files Only) to prepare for a co-simulation, I get the following prompt ... "The shell geometry is very large (253437 connections); so, converting to Parasolid geometry may take a long time. Do you want to Continue?"

I'm confused because I didn't add any new geometry from the last time I did a "Files Only" analysis and that worked fine (and has been working for a few months without issue). Was it the new clearance and contact definitions? Could it be that some parts are not hidden so it's pulling in geometry that wasn't visible before? Not really sure of the cause for this significant computation time hit to my workflow. 

Best, James

2021.0.1 Adams Car

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  • 0

    Hi James. Yes, the change in behavior is due to the clearance/contact definitions. Normally, geometry isn't written to the adm file since Solver wouldn't care about it. But obviously Solver needs geometry in the case of clearance and contact. View converts your shell geometry into Parasolid for consumption by Solver. I'm curious how long this operation takes. I've seen cases where's it's unbearably slow. If that's your experience, let us know!

  • 0 in reply to greg.wheeler

    Greg, thanks for the response. I figured it was the clearance requests, they seem pretty taxing overall. Do you think I could abridge this by computing clearances after the analysis in post-processing? It takes about 1hr for the "Files Only" analysis to complete the 253437 connections. I might try to reduce the number of clearances in this case to only what's absolutely necessary.

  • 0 in reply to James Parkus

    If it takes an hour just to prepare your model for Solver, then we have a performance bug that we can investigate.

    Reducing the number of clearances won't help, unless that would also reduce the number of individual shell objects that need to be converted to Parasolid.

    If it is possible for you to use Parasolid geometry in your template instead of shell geometry, that would avoid this geometry conversion step when you submit an analysis.

  • 0 in reply to greg.wheeler

    Understood, I can try to switch everything over to Parasolids. I've never worried too much about the difference of those two until now, but that's workable. Just to be clear, I am using 2021.0.1 so this may not be the case in newer Adams versions. Unfortunately, I am still unable to use newer versions of Adams for this specific effort. 

    I will attempt some clean-up and let you know how it goes.

  • 0 in reply to greg.wheeler

    I found a few errors when I tried to load the .adm file using the instructions for debugging in this Knowledge Center article (AEI-Initialize: Error in initialization during Adams/Matlab co-simulation). It spit out a bunch of errors with the updated contacts and recently added clearances. Looks like I made a mistake when assigning the J Contact Solid. I selected PART_NAME.SOLID_NAME.SHELL_NAME instead of just PART_NAME.SOLID_NAME, and those were the shells that were causing the tremendous slowdown in the model preparation. I fixed those definitions and the waiting period is gone! Back to normal. Another learning moment! Thanks very much for the help Greg!!

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