Add the Solid-Shell Connection node to create transitions between domains modeled using the Solid Mechanics or Multibody Dynamics interfaces and boundaries modeled using the Shell interface.

The Solid-Shell Connection node is only available with some COMSOL products (see http://www.comsol.com/products/specifications/)

Select the Connection type — Solid boundaries to shell edges, Solid and shell shared boundaries, or Solid and shell parallel boundaries.

For the two first options, there is an automatic search for possible adjacent geometrical objects. If you want to modify the selections, select the Manual control of selections check box. If to deselect it, the selections will be replaced by the automatic ones.

If the automatic selection is not sufficient, select the Manual control of selections check box. Then, select the connected solid boundaries in the Boundary Selection, Solid section and the corresponding shell edges in the Edge Selection, Shell section.

Select Connected area defined by — Shell thickness, Selected solid boundaries, or Distance from shell midsurface. This parameter determines how much of the selected solid boundaries that are connected to the shell. The default is that a distance from the shell edge having the size of the half the shell thickness in both perpendicular directions is connected. Using Selected solid boundaries connects the selected boundaries in their entirety to the shell. If you select Distance from shell midsurface, enter a Distance d. This value is used instead of the half the shell thickness for defining the connection distance.

Select a Method — Rigid or Flexible. The Rigid version of the coupling only adds constraints to the boundary of the solid, which in general causes local disturbances of the stress field, since the thickness cannot change. When using the Flexible coupling, three extra degrees of freedom are added along the shell edge. This allows for a more accurate description of the transition, but the model can in some cases become underconstrained if the mesh on the solid is very coarse.

You can modify the Connection tolerance Δ when either of the options Shell thickness or Distance from shell midsurface are used. The search distance is slightly extended by the distance Δ. The default value is 0.5% of the shell thickness, which allows for small inaccuracies on for example a curved geometry.

If the automatic selection is not sufficient, select the Manual control of selections check box. Then, select the connected boundaries in the Boundary Selection section.

Select the connected solid boundaries in the Boundary Selection, Solid section and the corresponding shell edges in the Boundary Selection, Shell section.

Select Distance evaluation — Shell properties, Geometrical distance, or User defined. This parameter determines how the coupling treats the determination of the connection distance, used when expressing th coupling between translation and rotation. When Shell properties is selected, the distance is based on the shell thickness and offset, so that a distance equal to half the shell thickness is used. If you select Geometrical distance, the connection distance is computed from the geometrical distance between the selected boundaries. For User defined, enter a Distance d, which defines the connection distance.