The Beam (beam) interface (), found under the Structural Mechanics branch () when adding a physics interface, is used for modeling slender structural elements, having a significant bending stiffness. The formulation allows geometric nonlinearity, with large rotations and small strains, and beams can be modeled on 2D boundaries and 3D edges.

Among the computed results are displacements, rotations, stresses, strains, and section forces. In addition to giving the beam properties explicitly in terms of area, moment of inertia, and so on, several predefined common cross-section types are available. Cross section data to be used in Cross Section Data settings can be computed using The Beam Cross Section Interface.

When this physics interface is added, these default nodes are also added to the Model Builder: Linear Elastic Material, Cross Section Data, Free (a condition where points are free, with no loads or constraints), and Initial Values. Then, from the Physics toolbar, add other nodes that implement, for example, loads and constraints. You can also right-click Beam to select physics features from the context menu.

The Label is the default physics interface name.

The Name is used primarily as a scope prefix for variables defined by the physics interface. Refer to such physics interface variables in expressions using the pattern <name>.<variable_name>. In order to distinguish between variables belonging to different physics interfaces, the name string must be unique. Only letters, numbers, and underscores (_) are permitted in the Name field. The first character must be a letter.

The default Name (for the first physics interface in the model) is beam.

Select Euler-Bernoulli or Timoshenko to use the appropriate beam theory. Timoshenko theory includes the effects of shear flexibility and rotary inertia, and is appropriate for beams with cross section dimensions which are large relative to the length of the beam.

Enter the default coordinates for the Reference point for moment computation xref. The resulting moments (applied or as reactions) are then computed relative to this reference point. During the results and analysis stage, the coordinates can be changed in the Parameters section in the result nodes.