Reply To: Bolt pretension object in Ansys2022

[peteroznewman]

The Program Controlled option uses a small rotation assumption. In most models, the surfaces the head and nut/thread attach to do not rotate in space by large angles. When the shank of the bolt is split to apply the pretension, the direction they pull toward each other is fixed in space along the axis of the bolt.

Some models undergo large rotation of the parts in space when the load is applied. Those models need Large Deflection turned on under the Analysis settings.  Bolt Pretension loads in those models should use the Joint formulation because that will allow the pretension pull direction to rotate in space with the bolt shank which is more accurate than leaving the pull direction fixed at the initial axis of the shank.