Contact formulation for beam with bolted joints, using shell elements
Hi all, newcomer to the forums here with a bolt joining problem.
I am trying to model a beam, split across the middle, joined with a top and bottom plate and 4 bolts through it. Geometry as seen in figure 1.
Figure 1 : Full geometry of experimental model
I've made a 3D and 2D model and I am now making a model which models the beam and plates with shell elements and the bolts as full 3D. However, I've ran into some issues with establishing contact.
I would like to establish a frictional/frictionless contact between the bolt and the holes of the middle beams (the bolts are bonded to the top and bottom clamps and that works just fine) and also I would like to establish a frictional/frictionless contact between the end faces of the beams.
Figure 2: Bonded connection for top and bottom of bolts with top and bottom clamps respectively
Figure 3: Frictionless connection of mid-bolts to beam halves
Figure 4: Frictionless contact between beam halves
My connections so far are pictured in figures 2-4 and the resulting issues displacement in a modal analysis is pictured in figure 5 and 6.
Figure 5: Bolts not interacting with bolt holes
Figure 6: Beam halves clipping through each other
As seen, the problem is any other contact aside from "Bonded" between the bolts and the two beam halves results in invalid results (see figure 5) additionally the two beam halves clip through each other (figure 6).
How would I go about establishing effective frictionless contact between bolts - bolt holes and between the ends of the beams, in such a way it also allows pretension further down the line? Bearing in mind the beams are made of shells and are not solid.
Attached is my project archive, SGBJM Modal contains the model as seen above.