We had our Ansys vendor, DRD Technology in Tulsa, open this issue up with Ansys. Ansys has admitted there is a problem, and they are (reportedly) working on a solution. But they have been working a long time. We have sent several files their way to use in troubleshooting. So far they report no results. The problem first happened for us in Release 2022 R2. I think it was also present in 2021, though. We upgraded to 2023 R1 because of the problem, but we got no relief. We have done what Rick did, export an independent SCDOC file, import that file into a new Static Analysis block in Workbench. It works, but since our models are very complex, it means losing all the setup work in Mechanical, so we avoid it. That said, the cause of the problem has been identified. It is caused by the Undo button. The workaround, however, IS NOT to limit the number of Undo saves in the SpaceClaim Options app. That will not help. The only thing that will work, besides Rick’s export-import idea, is to purge the Undo list when SpaceClaim gets too slow. Ram usage will drop back down to the baseline value and start building again from there.
I should add this. While Ansys' response to this problem has been less than stellar, DRD Technology has pursued it aggressively. They identified the cause as being the Undo option. And it was also their aggressive pursuit that got Ansys to finally put it in their bug list. Kudo's to DRD.