Shell-Beam Connection

Add the multiphysics node (

) to create transitions between boundaries or edges modeled using the Shell interface and edges or points modeled using the Beam interface.

The node is only available with some COMSOL products (see https://www.comsol.com/products/specifications/).

Connection Settings

Select the — , , , or .

For all options except , there is an automatic search for possible adjacent geometrical objects. If you want to modify the selections, select the check box. If you clear it again, the selections will be replaced by the automatic ones.

Shell Edges to Beam Points

If the automatic selection is not sufficient, select the check box. Then, select the connected shell edges in the section and the corresponding beam points in the section.

Select a —, , , or .

•

Using makes all selected edges rigidly connected to the point on the beam.

•

For , all parts on the shell edge, which are within the default distance from the beam point, are connected. This distance is determined by the cross section properties of the beam. It is contained in the variable beam.re as described in the documentation for The Beam Interface.

•

For enter a rc. All parts on the shell edge, which are within the given distance from the beam point, are connected.

•

For enter a Boolean expression in the text field. The beam is connected to the selected shell edge wherever the expression has a nonzero value. The default value is 1, which is equivalent to using the option.

Shared Edges

If the automatic selection is not sufficient, select the check box. Then, select the connected edges in the section.

Select an — or .

•

For enter an ζ.

•

For enter values for d0 in the table. The offset is the vector from the reference surface of the shell to the actual position of the beam.

Parallel Edges

Enter a value for the Δθ. The default is 1 degree. The two edges are connected only where they are parallel within the specified tolerance.

Shell Boundaries to Beam Points

If the automatic selection is not sufficient, select the check box. Then, select the connected shell boundaries in the section and the corresponding beam points in the section.

Select an option from the list — , , , or .

•

Using makes all selected boundaries rigidly connected to the point on the beam.

•

For , all parts on the shell boundary, which are within a default distance from the beam point, are connected. This distance is determined by the cross section properties of the beam. It is contained in the variable beam.re as described in the documentation for The Beam Interface.

•

For enter a rc. All parts on the shell edge, which are within the given distance from the beam point, are connected.

•

For enter a Boolean expression in the text field. The beam is connected to the selected shell boundary wherever the expression has a nonzero value. The default value is 1, which is equivalent to using the option.

•

For more information about coupling different element types, see Coupling Techniques.

•

For details about the formulation of this coupling, see Connection Between Shells and Beams

These types of couplings will commonly generate many constraints, possibly even conflicting with other constraints coming from ordinary boundary conditions. For methods of resolving potential problems, see

•

Elemental and Nodal Constraints

•

Suppressing Constraints on Lower Dimensions

When there are many interconnected constraints, it may also be useful to change Null-Space Function to or , but doing so may increase the memory consumption significantly.


	Examples of all types of couplings between shells and beams are shown in Connecting Shells and Beams: Application Library path Structural_Mechanics_Module/Beams_and_Shells/shell_beam_connection