I have a huge model with multi-bolt regions. The problem is that the solid model does not contain the physical bolts, so how do I create bolts to keep all the plates in the model together? Bolt regions on some parts are concentric attaching many plates.
Is there a way to somehow create virtual bolt conditions with some preload without actually creating bolts? That would be very helpful.
You could try the Weld/Fastener (CWELD/CFAST) element. It's a node-to-node type element that is defined by a "patch". My understanding is it "grabs" elements within a specified diameter and connects them.
I've not used them before so I can't offer much guidance, so definately a test model and checking the NX Nastran help file for info is prudent.
I don't know if you can apply bolt preload to them.
Here's a pic of an example model in the Element Reference Library: