peteroznewman
Subscriber

You cannot change an existing model from 3D to 2D. It doesn't work. I don't know why.

To build a 2D model, you must start with a new Static Structural model, and on the Geometry cell in Workbench, set the Analysis Type to 2D before you open the model.  I assume you have sheet bodies in the X-Y plane with Z = 0.  That is another requirement.