2D-Axisymmetric equivalent boundary conditions of a real 3D problem

[Yunus9696]

Dear colleagues
Hope you're fine.

I'm modeling a 2D-Axisymmetric model of a dental implant in the jawbone.
I need to know if the applied boundary conditions are reasonable?
I have only constrained the boundary of the cortical bone in the vertical and rotational (about the axis of rotation) directions, since the stiffness of the cortical bone is 4 times more than the trabecular bone.

The 3D section of the real problem (implant, cortical bone and trabecular bone) and the corresponding 2D-Axisymmetric model with the boundary of the cortical bone specified by a black dash line is kindly attached

What are the reasonable boundary conditions (if the applied ones are not) to prevent unrealistic over/under constrained condition?
Any provided explanations and references would be appreciated.

With regards.

 

[FEA way]

First of all, keep in mind that in this 2D model you assume that the thread is axisymmetric while in the 3D model (and real life) the thread is spiral. And you won’t be able to model tightening of the screw or bending. Only axial load can be applied. You don’t need any rotational BCs in axisymmetric model, only constraints in X and Y direction can be applied.

Also, I don’t think that applying a fixed BC between the cortical and trabecular bone in this axisymmetric model is a good idea since you should model interaction between them - using contact or tie constraint. You can fix the bottom edge of the model and that should be sufficient. But I would also look for research papers involving simplified axisymmetric models of dental implants.