A closer look at the material card may provide some insight. If the material has time or strain based failure, this could happen but it is highly unlikely that the entire part could disappear at the same time. Since you are posing this question under the post, I presume the material the part belongs is GURSON in which case, a component analysis like a uniaxial test can be performed to see if the failure is pre-mature. Just some best guesses and I could be misleading.

Suri Bala

I have a model that runs but half the model disappears middway during the run but continues to run with the other components to the end. What can cause the model to just make several cmpts disappear like this? – thanks

Tom