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Warning on boundary conditions

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tito662

Structural
Joined
Jul 5, 2007
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12
Location
FR
I m defininf symetry boundary conditions on a structure but Abaqus is giving me the following message on every node at the symetry section and is ignoring the symetry condition
DEGREE OF FREEDOM 3 IS NOT ACTIVE ON NODE 42284 INSTANCE
RAIDISSEUR-1 - THIS BOUNDARY CONDITION IS IGNORED
Can anyone help?



 
Is it a 3D problem otherwise in 2D there is no freedom 3.

corus
 
It is a 3D problem...
When i define symetry i have to block translation along direction 3 and rotation around axis 1 and 2(degrees of freedom 4 and 5)...For parts neshed with solid elements:
I have the following message for solid elements:
Degree of freedom 4(or 5) is not active in the model on node...this boundary condition will be ignored..

For the part (meshed with shell) i have the following'
Degree of freedom 3 is not active in the model..

So for solid elements do i have only to restrain displacement along direction 3?
And for the shells i dont define boundary conditions?
Thanks!
 
what's the exactly element type you are using then?
 
Did you have coupling or tie surface at those nodes?
 
Solid continuum elements like C3D8 do not have rotational dof's, only translational, hence the warning when you try to apply constraints to dof 4& 5.

Not sure about the 'shell' elements though...please post excactly what elements you are using.

Martin

Martin Stokes CEng MIMechE
 
Yes Yomann i have tie surfaces and coupling..
Do u think i have the warnings cause i m trying to constrain nodes which are tied to other constrained nodes due to the tied surfaces?
 
I belive that is the case then, as you already tied or coupled the surface, that dof is already be fixed by the tie or coupling.
I personaly excluded that dof in the symmerty node and make the model look more tidy and save the analysis to print out unnessary message, but I think it does not matter in term of the results in either way.
It is a warning not a error, right?
 
Ure right
Thanks for ur help
 
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