Okay, I've searched and found other discussions where equilibrium wasn't achieved but they were all assemblies.
I have a single part - flat sheet of glass as a solid - input thermal data from a flow simulation and temperature dependent material properties.
Add 2 X/Y restraints to prevent it flying off into space.
Use a virtual wall to represent it sitting on a flat surface.
The temperature differences should cause it to distort and bow up in certain places (bowing down being resisted by the virtual wall).
I keep getting an "Equilibrium is not achieved" dialog to save up to the current results.
Is there a way to force it to keep calculating to see if it does converge? I'm not in a time crunch so letting it run longer wouldn't be an issue - if it gave me that option.
I can run it without the virtual wall and it solves, but in that case the glass droops all over the place as if only supported at the corners. This suggests the virtual wall is ultimately linked to the problem.