The Truss (truss) interface (), found under the Structural Mechanics branch () when adding a physics interface, is used for modeling slender elements that can only sustain axial forces. It can be used for analyzing truss works where the edges are straight, or to model sagging cables like the deformation of a wire exposed to gravity. It is available in 3D and 2D. Geometric nonlinearity can be taken into account.

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), Straight Edge Constraint (to ensure that the points lie on a straight line between the endpoints of the edge or boundary), and Initial Values. Then, from the Physics toolbar, you can add other nodes that implement, for example, loads and constraints. You can also right-click Truss 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 truss.

From the Structural transient behavior list, select Include inertial terms (the default) or Quasistatic. Use Quasistatic to treat the dynamic behavior as quasi static (with no mass effects; that is, no second-order time derivatives). Selecting this option gives a more efficient solution for problems where the variation in time is slow when compared to the natural frequencies of the system. The default solver for the time stepping is changed from Generalized alpha to BDF when Quasistatic is selected.

The dependent variable (field variable) is for the Displacement field u which has two components (u, v) in 2D and three components (u, v, and w) in 3D. The name can be changed but the names of fields and dependent variables must be unique within a model.