I can't get a simple non linear problem to run. See screenshot below.

Very simple square bar made from a material that has two CTEs, above and below the glass transition temperature. I'm cooling the bar from above Tg to well below Tg over the default time of 1 second.

For some reason at ~0.65s I get the following error message:

*Solution failure in a Step>1, it could be due to:*

* The solution may be at a buckling or limit point, i.e.,*

* displacements grow large under constant forces. If so,*

* for force control or contact problems, this is the end*

* of solution (check out the response graphs).*

The solution is set up as follows:

I've restrained the end in different ways in case I was generating very strains but get exactly the same error at exactly the same time.

Any ideas where I'm going wrong?

I've found the problem !

Looking through the material curves, one of them only started at 23 deg C, where the solution was stopping. I changed the curve so it started at -50 deg C and the problem ran.

Thanks for your help Bill.