Free
The Free node is the default boundary condition. It means that there are no constraints and no loads acting on the boundary. When the physics interfaces is added, a default Free node is added. If you look at the selections for this node, it will show all boundaries which do not have any boundary conditions applied.
In each physics interface, the Free node applies to a geometric entity which is one level below the one on which the physics is active:
For the Beam and Truss interfaces, the Free node applies to points.
You can manually add Free nodes to override other boundary conditions. This is however seldom needed.
Location in User Interface
Context Menus
Solid Mechanics>Free
Shell>Free
Plate>Free
Layered Shell>Free
Membrane>Free
Beam>Free
Truss>Free
Multibody Dynamics>Free
Ribbon
Physics tab with a physics interface selected:
Boundaries>Solid Mechanics>Free
Boundaries>Plate>Free
Boundaries>Multibody Dynamics>Free
Edges>Shell>Free
Edges>Layered Shell>Free
Edges>Membrane>Free
Points>Beam>Free
Points>Truss>Free