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Active Member
SKARLEZ
Posts: 7
Registered: ‎10-26-2010
Accepted Solution

Problem with Constrains in SIM 360

294 Views, 5 Replies
10-06-2013 06:20 AM

Hi everybody...
Could any one please advise why SIM 360 pop up a warning when you apply pinned constrains in both axles???
Note: Both constrains are fixed to radial & axial position... Check pic!

I have to admit that in the beginning I thought that this is sensible.
However I found a nice video in the following link that demonstrates the aforementioned constrains as valid

Boundary Conditions for Inventor to solve this simulation....

( http://usa.autodesk.com/adsk/servlet/item?siteID=123112&id=12953291&linkID=9242016 )***



***Check the bottom of this page and find the "Multiple Areas of High Stress" video.
     Click to play if you cannot watch the video right click on the preview and click "save as..."

I would appreciate a lot If any one can comment ...

Cheers!

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Employee
Tomi-Autodesk
Posts: 18
Registered: ‎06-11-2009

Re: Problem with Constrains in SIM 360

10-06-2013 10:55 AM in reply to: SKARLEZ

Hello,

 

You're bringing up a good point- The warning just touches on the possibility of the part (or connected group of parts) not being fully constrained- for example if the holes were concentric, then the part would be able to rotate freely around that axis- in your case that does not apply, as the different locations of holes prevents the part from rotation along the axis- therefor you can ignore the warning-

 

Clearly the underlying logic for this message has room for improvements, to be considered in future -

 

Thanks

Tomi

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Active Member
SKARLEZ
Posts: 7
Registered: ‎10-26-2010

Re: Problem with Constrains in SIM 360

10-08-2013 02:26 AM in reply to: Tomi-Autodesk

Hi Tomi 

 

Forgive my delayed response... and let me thank you for your prompt reply.
You are right and I agree with your post... 
While I was waiting for a potential answer I had a quick chat with a friend of mine. 
We actually came up with the same assumption. 
I am happy to hear pretty much the same words from a person of Autodesk.

Just to make that clear you are saying that...

This kind of boundary condition speaking for this specific problem (attached pic) 

will not cause any problems and the solution will be equally robust and reliable despite the warning!

Let me know your thoughts!

Best Regards
Ioannis

 

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Employee
Tomi-Autodesk
Posts: 18
Registered: ‎06-11-2009

Re: Problem with Constrains in SIM 360

10-08-2013 09:31 AM in reply to: SKARLEZ

Hi Ioannis,

 

I'm glad that helped and we can improve the messaging logic in future- as mentioned, that particular case posted earlier is ok, so you can ignore the warning. Bottom line is that for general loading the part cannot have free movements (translation/rotation) in any direction (i.e. no rigid body modes)- if the holes are not aligned/ (co-centric) then the free rotation around axis is prevented by other constraint components-

 

Regards,

Tomi

 

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Member
jpate015
Posts: 5
Registered: ‎09-17-2013

Re: Problem with Constrains in SIM 360

11-09-2013 09:11 AM in reply to: Tomi-Autodesk

I have a problem with Autodesk Simulation Mechanical 360.  In the regular Sim Mech, the part I am trying to run works fine.  In 360, frictionless constraints do not work.  I can suppress and it will run, but it is not realistic at that point.  If I have any kind of frictionless constraint it will fail.

 

Any thoughts?

 

Thanks for the help,

Pate

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Employee
Jimmy_Yuan|Autodesk
Posts: 147
Registered: ‎04-28-2008

Re: Problem with Constrains in SIM 360

11-10-2013 06:06 PM in reply to: jpate015

Hi Pate,

 

Could you please send us an example with the pre-processing settings (or models + pre-processing description) so that we can take a close look at it? If you like, you can email it to me shuangxi(dot)yuan(at)autodesk.com. Thanks



Jimmy Yuan
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