Solved! Go to Solution.
First place to check is in the .f06 text file which is created wherever your analysis files are being created. Check for all the WARNINGS and ERRORS. Some of the warnings may be generic (eg. no rotational stiffness for solid element nodes, if you are using solids), but otherwise you should see what message(s) are advising as to why the analysis did not run. Also, NX Nastran attempts to apply the pre-load in a single sub-step. This may be difficult - if the physics is challenging - and can be forced to smaller sub-divisions. Also, just need to be 100% sure... your pre-load value is set as positive, not negative?