Truss elements

Truss elements are rods that can carry only tensile or compressive loads. They have no resistance to bending; therefore, they are useful for modeling pin-jointed frames. Moreover, truss elements can be used as an approximation for cables or strings (for example, in a tennis racket). Trusses are also sometimes used to represent reinforcement within other elements. The overhead hoist model in Abaqus Basics, uses truss elements.

All truss element names begin with the letter “T.” The next two characters indicate the dimensionality of the element—“2D” for two-dimensional trusses and “3D” for three-dimensional trusses. The final character represents the number of nodes in the element.

Truss element library

Linear and quadratic trusses are available in two and three dimensions. Quadratic trusses are not available in Abaqus/Explicit.

Degrees of freedom

Truss elements have only translational degrees of freedom at each node. Three-dimensional truss elements have degrees of freedom 1, 2, and 3, while two-dimensional truss elements have degrees of freedom 1 and 2.

Element properties

All truss elements must refer to a truss section property that associates a material property definition with the element and specifies its cross-sectional area.

Formulation and integration

In addition to the standard formulation, a hybrid truss element formulation is available in Abaqus/Standard. It is useful for modeling very stiff links whose stiffness is much greater than that of the overall structure.

Element output variables

Axial stress and strain are available as output for truss elements.