Learning Forum

[peteroznewman]

nWhen using a line body to represent a bolt connecting two plates, the question is how long should the line body be. The answer is it depends on whether it is a nut and bolt or a bolt into a threaded hole. If it is a nut and bolt, then the line body should go the full length of the thickness of the two plates and use a fixed joint at each end to the flat face, not the hole diameter. nIf it a bolt and threaded hole, then the length can be the thickness of the plate with the clearance hole. In this case, the fixed joint to the threaded hole can be the full length of the hole, or the hole face could be divided if the thread depth is less than the hole depth. In either of these cases, if a Bolt Pretension load is applied to clamp the plates together, there must be 2 elements along the line body or the Bolt Pretension load will fail to be created.nWhen using a line body to represent a bolt with pretension used to clamp three plates together, where the bolted joint is designed to prevent slip, the same rules apply as above. There does not need to be any connection of the center plate to the line body. Frictional contact between the faces of the plates prevents the center plate from moving. If necessary, frictional contact could be added between the line body and the hole in the center plate to simulate the case where the applied loads exceed the frictional forces holding the center plate fixed, then contact with the bolt shaft can pick up the excessive shear forces.nUnderstand that Frictional contact will be converted to bonded contact during a Modal analysis, so it would be wise to split a large flat face with a 'washer ring' around the holes so that contact has a limited area.n