modeling bolts

Hello, I trying to inspect the forces and stress on a bolt pattern and its threads. I have a round plate with a circular bolt pattern and a round cylindrical body with a threaded hole pattern on it. I assume since i'm calculating the forces on the bolts that i can start without any pre-load on the bolts.
I noticed that the arbor press example does not model threads and instead uses blank flat un-threaded cylindrical bolt shanks affixed to the inside of their holes with a
LIAISON_MAIL=(_F(GROUP_MA_MAIT='Volume',GROUP_MA_ESCL='Face',),
boundary condition.
how good of approximation for a threaded hole is this?
Does this model accurately model thread failure or will the bulk wall material fail long after the threads would have failed?
Is there a better method for modeling bolt pullout/ thread failure in code aster?
should i just be circumventing this by ensuring that my minimum thread engagement will cause each bolt to fail before the threads do?
thankyou