Problem with Y nodal moments on nozzle flange

[DanielSchardine1226]

I've been having this problem off and on.  I'm modeling air cooled heat exchanger header boxes (fin fan) using AutoCAD 2007.  The boxes and nozzles are modeled as brick elements and the nozzle flanges are modeled as plate elements.  On some models, when I add a Y nodal moment to the flanges, the stress goes through the roof.  On other models, it works fine.  Any ideas?

[Sualp.Ozel]

Copy/Paste from help:

Plate elements are three- or four-node elements formulated in three-dimensional space. These elements are used to model and analyze objects such as pressure vessels, or structures such as automobile body parts.

The out-of-plane rotational DOF is not considered for plate elements. You can apply the other rotational DOFs and all the translational DOFs as needed.

Nodal forces, nodal moments (except when about an axis normal to the element face), pressures (normal to the element face), acceleration/gravity, centrifugal and thermal loads are supported.

[DanielSchardine1226]

The orientation of the model doesn't seem to make a difference.  It's only the Y nodal moments, regardless of the plane the plate is in.

[Sualp.Ozel]

Looking at the image you have attached the flange is drawn in the XZ plane which means Y is the out of plane rotation.

So per definition of the PLATE element, this element will not have this Degree of Freedom. If you have further questions on this subject feel free to contact tech support using the Autodesk subscription website. Remember to attach your Algor ARCHIVE file.

[DanielSchardine1226]

The attached model has 3 nozzles.  All have plate element flanges loaded with X,Y, and Z nodal forces and moments.  They are all in the same plane.  Only one has the problem.

[Sualp.Ozel]

Please send us the Archive file. (File: archive: create) Without this file, I can not see the Loads and Boundary Conditions you are applying to your geometry

[DanielSchardine1226]

The archive is too large to attach.  Can I send it to you another way?  It's about 4.5Mb.

[Sualp.Ozel]

please send an e-mail to aeinbox@autodesk.com