I'm working with an FEA project, about 200 load cases that I imported via Excel, and about 50 components that are a mix of honeycomb sandwich and 2-stack unstiffened. When I run detailed sizing on the project using all load cases, 2 components are returned with negative margins. Looking at the Excel stress report, I see about 5 or 6 load cases listed with negative margins. If I select only these load cases (un-checking all others on the project setup form) and re-run the sizing, I now see positive margins for these same load cases. Also, if I de-select this same set of load cases that originally produced negative margins and re-run including all others, load cases that were originally listed with positive margin are now negative. I wouldn't expect that the results for a given load case would be dependant on which other load cases are also selected, but that seems to be what I'm seeing. Any suggestions or help would be appreciated.
Thanks,
-Mike