FE Bolt model

[tataaero]

Hello,
I have come across a model where the bolts have been modelled as shown in the attached figure.

The two plates are solid elements with the upper and lower surface nodes on each plate at the hole edge are attached to beam elements representing the bolt by MPCs (bolt shear translations only (except one node which has all three translations)). The plate surfaces that are in contact connect to two seperate nodes on the bolt that are 1mm apart, although no such gap exists between the plates. Does anyone know why the bolts have been modelled this way?
Thanks

 

[rb1957]

modelling the plates as solid elements is understandable. the MPCs are somewhat "odd" (IMHO) ... mor typical would be a "spider mesh connecting the bore of the hole to a point on the CL (mid-thickness or mating surface) then using a beam element (or a CBUSH/CELAS, dof spring).

as is, the stiffness of the fastener is related to three beam elements, which sounds overly complicated.