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BMH
09-19-2010, 02:48 AM
Hello everyone, I am trying to finish up the chassis design and was trying to get some approximate FEA data using SW Simulation. After I set my loads and constraints, I click on the mesh to start meshing. After the meshing is complete, It comes out to the picture you see below. Anyone know what would cause this?


http://i56.tinypic.com/dexmxw.jpg
BMH
09-19-2010, 02:48 AM
Hello everyone, I am trying to finish up the chassis design and was trying to get some approximate FEA data using SW Simulation. After I set my loads and constraints, I click on the mesh to start meshing. After the meshing is complete, It comes out to the picture you see below. Anyone know what would cause this?


http://i56.tinypic.com/dexmxw.jpg
RollingCamel
09-19-2010, 01:43 PM
OOh yes it sometimes happen if you make some changes in the model. Try recalculating your joints and check that all members are treated as beams with the material you require.
BMH
09-20-2010, 01:24 AM
I tried that already. After solving for the results, the values I obtain appear to be about right, I'm just not able to determine where my max stresses, deflections, etc. are or get any nice pictures for reports.

I'm guessing it may be a glitch or something?
RollingCamel
09-21-2010, 11:52 AM
I don't really recall how I solved but it didn't produce acceptable results. Did you try it on another system?
Drew Price
09-21-2010, 03:34 PM
Are you modelling this with beam elements?

If so you can set the size of the little 'balloon' (I forget what SW calls them) that establishes tube intersections - if you have them set too large, it will think there are joints where there are no nodes.

If you're trying to model that as a shell / volume mesh in SW.... good luck. Something is awry with your constraints.



Drew
BMH
09-21-2010, 05:52 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Drew Price:
Are you modelling this with beam elements?

If so you can set the size of the little 'balloon' (I forget what SW calls them) that establishes tube intersections - if you have them set too large, it will think there are joints where there are no nodes.

If you're trying to model that as a shell / volume mesh in SW.... good luck. Something is awry with your constraints.



Drew </div></BLOCKQUOTE>


I am doing the beam element method. If you use weldments in solidworks, SW Simulation (or Cosmos) will automatically switch to beam elements..or thats what I thought I read.

As far as the "ballons," I think SW terms it as joints. I havent thought of playing around with the sizing...perhaps I will give that a try.
Drew Price
09-22-2010, 09:35 AM
Do that and see what happens. When you go in to edit the joint constraint you will see the 'envelope' that SW uses to define the joint.

Basically if you have multiple tubes coming within a certain distance of each other, the software will treat them as joined. You need to tweak what that minimum distance is.

IIRC there was a handy tutorial specifically on beam elements / weldments in the COSMOS tutorial section that explains it all so you can get it constrained correctly.



Drew