ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE TypeModel data LevelPartPart instance Abaqus/CAEProperty module Required parameters ELSET
Set this parameter equal to the name of the element set for which this
section is defined.
 MATERIAL
Set this parameter equal to the name of the material to be used with this
beam section definition.
 SECTION
Set this parameter equal to the name of the section type (see
Beam crosssection library).
The following crosssections are available for beam elements:
ARBITRARY, for an arbitrary section.
BOX, for a rectangular, hollow box section.
CIRC, for a solid circular section.
HEX, for a hollow hexagonal section.
I, for an Ibeam section.
L, for an Lbeam section.
PIPE, for a thinwalled circular section.
RECT, for a solid, rectangular section.
THICK PIPE, for a thickwalled circular section
(Abaqus/Standard only).
TRAPEZOID, for a trapezoidal section.
Set SECTION=ELBOW for elbow elements, which are available only in
Abaqus/Standard.
Optional parameters LUMPED
This parameter is relevant only for linear Timoshenko beam elements in
Abaqus/Standard.
Set LUMPED=YES (default) to use a lumped mass matrix in frequency extraction
and modal analysis procedures.
Set LUMPED=NO to use a mass matrix based on a cubic interpolation of
deflection and quadratic interpolation of the rotation fields in frequency
extraction and modal analysis procedures.
 POISSON
Set this parameter equal to the effective Poisson's ratio for the section to
provide uniform strain in the section because of strain of the beam axis (so
that the beam changes crosssectional area when it is stretched). The value of
the effective Poisson's ratio must be between −1.0 and 0.5. The default is POISSON=0. A value of 0.5 will enforce
incompressible behavior of the element.
This parameter is used only in largedisplacement analyses. It is not used
with elbow elements or with element types B23, B33, PIPE21, PIPE22, and the equivalent “hybrid” elements (which are available only
in
Abaqus/Standard).
 ROTARY INERTIA
This parameter is relevant only for threedimensional Timoshenko beam
elements.
Set ROTARY INERTIA=EXACT (default) to use the exact rotary inertia corresponding to the
beam crosssection geometry in dynamic and eigenfrequency extraction
procedures.
Set ROTARY INERTIA=ISOTROPIC to use an approximate rotary inertia for the crosssection. In
Abaqus/Standard
the rotary inertia associated with the torsional mode of deformation is used
for all rotational degrees of freedom. In
Abaqus/Explicit
the rotary inertia for all rotational degrees of freedom is equal to a scaled
flexural inertia with a scaling factor chosen to maximize the stable time
increment.
 TEMPERATURE
Use this parameter to select the mode of temperature and field variable
input used on the
FIELD, the
INITIAL CONDITIONS, or the
TEMPERATURE options.
For beam elements set TEMPERATURE=GRADIENTS (default) to specify temperatures and field variables as
values at the origin of the crosssection, together with gradients with respect
to the 2direction and, for beams in space, the 1direction of the section. Set
TEMPERATURE=VALUES to give temperatures and field variables as values at the
points shown in the beam section descriptions (see
Beam crosssection library).
For elbow elements set TEMPERATURE=GRADIENTS (default) to specify temperatures and field variables at the
middle of the pipe wall and the gradient through the pipe thickness. Set TEMPERATURE=VALUES to give temperatures and field variables as values at points
through the section, as shown in
Pipes and pipebends with deforming crosssections: elbow elements.
Data lines for BOX, CIRC, HEX, I, L, PIPE, RECT, THICK PIPE, and TRAPEZOID sections First line
Beam section geometric data. Values should be given as specified in
Beam crosssection library
for the chosen section type.
Etc.
 Second line (optional; enter a blank line if the default values
are to be used)
First direction cosine of the first beam section axis.
Second direction cosine of the first beam section axis.
Third direction cosine of the first beam section axis.
The entries on this line must be (0, 0, −1) for planar beams. The default
for beams in space is (0, 0, −1) if the first beam section axis is not defined
by an additional node in the element's connectivity. See
Beam element crosssection orientation
for details.
 Third line
(optional)
Number of integration points in the first direction or branch. This number
must be an odd number (for Simpson's integration), unless noted otherwise in
Beam crosssection library.
Number of integration points in the second direction or branch. This number
must be an odd number (for Simpson's integration), unless noted otherwise in
Beam crosssection library.
This entry is needed for the THICK PIPE section, as well as for beams in space.
Number of integration points in the third direction or branch. This number
must be an odd number (for Simpson's integration), unless noted otherwise in
Beam crosssection library.
This entry is needed only for Ibeams.
Data lines for ARBITRARY sections First line
Number of segments making up the section.
Local 1coordinate of first point defining the section.
Local 2coordinate of first point defining the section.
Local 1coordinate of second point defining the section.
Local 2coordinate of second point defining the section.
Thickness of first segment.
 Second line
Local 1coordinate of next section point.
Local 2coordinate of next section point.
Thickness of segment ending at this point.
Repeat the second data line as
often as necessary to define the ARBITRARY section.
 Third line (optional)
First direction cosine of the first beam section axis.
Second direction cosine of the first beam section axis.
Third direction cosine of the first beam section axis.
The entries on this line must be (0, 0, −1) for planar beams. The default
for beams in space is (0, 0, −1) if the first beam section axis is not defined
by an additional node in the element's connectivity. See
Beam element crosssection orientation
for details.
Data lines for ELBOW sections First line
Outside radius of the pipe, r.
Pipe wall thickness, t.
Elbow torus radius, R, measured to the pipe axis. For a
straight pipe, set $R=0$.
 Second line
Enter the
coordinates of the point of intersection of the tangents to the straight pipe
segments adjoining the elbow, or, if this section is associated with straight
pipes, the coordinates of a point off the pipe axis. The second crosssectional
axis will lie in the plane thus defined, with its positive direction pointing
toward this offaxis point. First coordinate of the point.
Second coordinate of the point.
Third coordinate of the point.
 Third line
Number of integration points through the pipe wall thickness. This number
must be an odd number. (The default is 5.)
Number of integration points around the pipe. (The default is 20.)
Number of ovalization modes around the pipe (maximum 6). The section can be
used with 0 (zero) ovalization modes, in which case uniform radial expansion
only is included.
