Continuity
Add a Continuity node to connect two layered shell boundaries sharing a common edge and having different layered materials.
The continuity constraint is added on the common edge in the through-thickness direction.
Layer Selection
Select Source and Destination layered materials from all the Layered Material Link and Layered Material Stack available in the component. All the edges are selected by default and the common edges between the two layered materials becomes applicable automatically. Optionally you can remove some of the edges if you do not want to enforce the continuity on all the common edges.
In the Source, select the Layered Materials based on what you want to use in the continuity constraints. This option is available only when Layered Material Stack is chosen.
In the Destination, select the Layered Materials based on what you want to use in the continuity constraints. In addition to this, an Offset can be specified on the destination side which decides the actual connection area between the two layered materials.
You can swap the source and destination by clicking Swap Source and Destination ().
In order to visualize the connection, click Layer Cross Section Preview ().
You can use the Clear All () and Reset to Default () buttons to clear or reset all the selections as well as the offset values in two cases, respectively.
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  Layered Shell selected: