ANSYS APDL "at least 1 small equation solver pivot term"

[zazadeh]

Hi all,

I've created a cylinder and applied boundary conditions and pressure in the inside of the cylinder (cylinder is expand due to the pressure inside of it) (the model also is created by nodes and elements using shell 181). the analysis works until I add a frame to the inside of the cylinder in order to support the cylinder from expanding. after adding the supporting frame (which is also created by nodes and elements), I kept receiving "There is at least 1 small equation solver pivot term. Please check for an insufficiently constrained model" error message.

I don't know to con constraint or unconstraint the model!

Any help would be great.

Thanks,

Azadeh

 

[rickfischer51]

Does the model run? If so, the small pivot term could be a weak spring. Turn off weak springs and try running again.


Rick Fischer
Principal Engineer
Argonne National Laboratory

 

[IceBreakerSours]

I do not speak ANSYS so this may not be of much use but I wonder if the rotational DOFs on the nodes of the shell elements need to be constrained.

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