Pinned
The Pinned node adds an edge, boundary, domain, or point condition that fixes the translations in all directions; that is, all displacements are zero. The rotations are not constrained.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.
In the COMSOL Multiphysics Reference Manual:
Location in User Interface
Context Menus
Ribbon
Physics tab with Shell selected:
Physics tab with Plate selected: