Truss Elements

Truss Elements

Truss 1D element

Represents linear isoparametric truss element in 1D. The elements are assumed to be located along the x-axis. Requires cross section area to be specified. The element features are summarized in Table 1.

Table 1 truss1d element summary

Keyword	truss1d
Description	1D truss element
Unknowns	Single dof (u-displacement) is required in each node
Approximation	Linear approximation of displacement and geometry
Integration	Exact
Features	Full dynamic analysis support, Full nonlocal constitutive support, Adaptivity support
CS properties	Area is required
Loads	Body loads are supported. Boundary loads are not supported in current implementation
Status	Reliable
Tests/Examples	sm/con2dpm8.in, sm/con2dpm5.in, sm/isoasymm01.in, partests/dyn_bar03/dyn_bar03.oofem.in, partests/dyn_bar03/bar03.statics.oofem.in, sm/Mises02.in, sm/idm02.in, sm/idm03.in, sm/idm04.in, sm/idm05.in (and 9 more)

Truss 2D element

Two node linear isoparametric truss element for 2D analysis. The element geometry can be specified in (x,z), (x,y), or (y,z) plane. The element features are summarized in Table Table 2.

Fig. 1 Truss2d element in (x,z) plane.

Table 2 truss2d element summary

Keyword	truss2d
Description	2D truss element
Specific parameters	[cs (in)]
Parameters	cs: this parameter can be used to change default definition plane. The supported values of cs are following: 0 for (x,z) plane (default), 1 for (x,y) plane, and 3 for (y,z) plane.
Unknowns	Two dofs representing displacements in definition plane are required in each node. The element can be used in different planes, default definition plane is (x,z). The parameter cs can be used to change default definition plane.
Approximation	Linear approximation of displacements and geometry.
Integration	Exact.
Features	Full dynamic analysis support. Full nonlocal constitutive support.
CS properties	cross section area should be provided.
Loads	Edge loads are supported, Edge number should be equal to 1
Status	Reliable
Tests/Examples	sm/linear_constraint_1.in, sm/linear_constraint_2.in, sm/linear_constraint_3.in, sm/patch160.in, partests/dyn_bar01/dyn_bar01.oofem.in, sm/trussb3_creep.in, sm/trussb3_relax.in, sm/steelRelaxMat2.in, sm/rotated_1.in, sm/rotated_2.in (and 7 more)

truss2d element summarytruss2dsummary

Truss 3D element

Two node linear isoparametric truss element for 3D analysis. The element geometry is specified in (x,y,z) space. The element features are summarized in Table Table 3.

Fig. 2 Truss3d element in (x,y,z) space.

Table 3 truss3d element summary

Keyword	truss3d
Description	3D truss element
Unknowns	Three displacement DOFs (in x, y, and z directions) are required in each node.
Approximation	Linear approximation of displacements and geometry.
Integration	Exact.
Features	Full dynamic analysis support. Full nonlocal constitutive support.
CS properties	cross section area should be provided.
Status	Reliable
Tests/Examples	sm/nldeidynamic1.in, sm/compoDamMat.in, sm/linkslip02.in