Bolt Pretension Problem
 

Hello All,

I have a bolt as a simple cylinder and a nut at the bottom.
I am trying to apply a pretension load on 1 face of bolt, but for some reasons when i press apply for geometry selection, the software doesn't select the surface (the surface does not turn into red with compression load arrow).
does this problem have to do with my model design? any help or advice is really appreciated.

Thanks