Nice work @BenLewis!
Regarding the symmetry boundary condition, I would like to add two comments:
-
generally I would try to replace a symmetry constraint with an equivalent fixed value constraint whenever possible. The reason is that a symmetry constraint always creates a linear relation between the DOFs of the nodes involved:
\vec n \cdot \vec u = 0, where \vec n is the element normal and \vec u the displacement vector. If now any DOF that is not exactly (and in numerical analysis usually nothing is exact) normal to the symmetry plane is constrained by another boundary condition or contact, the DOF will be over-constrained. By using a fixed value constraint and defining the mentioned DOF as unconstrained you won’t have a problem. Obviously this technique will not work if the symmetry plane is not orthogonal to any of the coordinate axes. -
In this particular analysis the symmetry happens not to be a problem. The problems when having symmetry and a slave surface of a physical contact sharing nodes are mostly observed when friction is involved and a Lagrangian contact formulation is used or in the above mentioned case where the mesh is too coarse.
Best,
Richard