Circular Symmetry

[Inv_kaos]

Is there some trick to applying circular symmetry? When I select it, it does not place anything in the browser or the graphical interface to show that it has been applied. If it doesn't do this but is working how do you edit the settings, just like applying it new each time? If it is working I seem to get bogus results, lots of random hot spots..

The help file doesn't go into detail but as far as I can tell I followed the same procedure.

To assist with applying it manually, is there any way to apply a translational boundary condition perpendicular to a specific face, rather than by global axis?

Cheers.

[S.LI]

For your first question, I'm not very sure your concern.

ASIM interface provides some easy way to apply special BCs.

For symmetric BCs, essentially it goes to "local coordinate system".

So this leads us to your second question. To apply BCs not along global axis, you need local coordinate systems.

[John_Holtz]

Hello,

You are correct that there are no glyphs shown on the model or entries in the browser when you use Cyclic Symmetry. The input is only shown in the dialog where it is originally defined.

Where are the random hot spots in the results occurring? Are they on one or both of the faces with the cyclic symmetry? Are they scattered throughout the model? The first one would indicate that step 2 in the documentation was not followed: "When creating the mesh, the nodes on one face must match the nodes on the opposite face". The second one would indicate that the model may not be statically stable, so the solver did not converge. See step 3 in the documentation.

Help > Autodesk Simulation > Setting Up and Performing the Analysis > Set Up Analyses > Linear > Loads and Constraints > Cyclic Symmetry

For your last item, S.Li is correct about using a local coordinate system. But there is no type of boundary condition that I know of that can do the same thing as cyclic symmetry. So, let us know if I am not understanding something.

[Inv_kaos]

Thanks for the coordinate system tip, it will come in handy if not for symmetry at least.

Hot spots are at the planes of symmetry, so I would not have matched the nodes. How would I go about this correctly? I have only modeled one piece of the pie.

With surface I can resist translation normal to the plane and rotation in the two other planes to get symmetry. With solids I have no rotational DOF so I have been just fixing translation normal to the plane to give (what appears to be) similar results. This I have been trying only when I can't get the circular symmetry (CS) to work but I assume it is not correct.. Could you elaborate on what the CS does differently?

Cheers

[S.LI]

I bet what you did is all right.

To fix all DOFs of three noncolliner points means fixing the whole plane, both translation and rotation.

To fix only normal directions of three noncolliner points implies to constraint one translational DOF and two rotational DOFs.