Simulation 2011 Weld Beads Causing High Stress

[andrewzeller2999]

I am running Simulation 2011.

I am having trouble getting fillet and groove welds to work properly when running a stress analysis.  Most of the time I am joining square tubing.  I have found that if I run a stress analysis with no weld bead, just making the surfaces as bonded contacts, the stress is actually much lower than if I add them in.  I read somewhere that  "High stress results may occur at the welds due to sliver elements such as highly distorted elements."

Does anyone have any tricks or tips to get the welds to accurately simulate stress?  The only workaround that I have though of so far is to physically model the welds and constrain them into my model.  This seems to give me fairly accurate results but is time consuming.

Thanks,

Andy

[Daren.Lawrence]

I understand you’re referring to “sliver” elements in your welds skewing your results in these areas. To get more confident results, you can adjust the average element size of the mesh in the faces around the welds, add fillets to avoid singularities, update the contacts, etc. And speaking of contacts, there is an open wishlist item (1239259) for welds to have Inventor automatically create bonded contacts. I hope this helps.

[fournien]

I just watched an offical Autodesk video tutorial that solves this exact problem. You just need to increase the number of h-refinements and it should work. This is happening because the simulation is over simplified therefore not accurate.

Here is the link (the whole video is very helpful too):

http://youtu.be/yQ1Io1MDG5M?t=15m24s