This method is more accurate than the spot-weld or raised pad method if the joint is subjected to a lot of prying. The other two methods do not address this issue. This method will have a lower shear stiffness than the other two because it is determined by the bending stiffness of the bolts. This method utilizes the contact option that will increase run time significantly, sometimes by orders of magnitude. Also, the use of contact and rigid connections with this method will not work with Thermal or Dynamic simulations.
To use this method, model a beam element to represent the bolt (use this nominal bolt diameter). Create a surface region on the part around the head/nut area of the parts equal to the size of the bolt head, nut or washer. Connect the ends of the beam to these regions using Rigid Connections. Defined Contact between the interface surfaces.
The very local stresses around the bolt locations will not be very accurate however the stress and deflection away from the local bolts areas should be good. Shear and tensile loads in these beams may be used to estimate the load carried by each bolt. You should ignore the bending stress in the bolt since in the real parts this will be carried by friction or transferred to a shear in the bolts when the clearance is taken up. Also ignore any compressive bolt loads since these would represent the bolts becoming loose.
