ProductsAbaqus/StandardAbaqus/Explicit
TypeModel data LevelPartPart instance
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 Cross-Section Library).
The following cross-sections 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 I-beam section.
-
L, for an L-beam section.
-
PIPE, for a thin-walled circular section.
-
RECT, for a solid, rectangular section.
-
THICK PIPE, for a thick-walled 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 cross-sectional 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 large-displacement 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 three-dimensional Timoshenko beam
elements.
Set ROTARY INERTIA=EXACT (default) to use the exact rotary inertia corresponding to the
beam cross-section geometry in dynamic and eigenfrequency extraction
procedures.
Set ROTARY INERTIA=ISOTROPIC to use an approximate rotary inertia for the cross-section. 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 cross-section, together with gradients with respect
to the 2-direction and, for beams in space, the 1-direction 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 Cross-Section 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 Cross-Sections: 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 Cross-Section Library
for the chosen section type. For solid circular sections only, you can specify
a distribution name to define a spatial distribution for the beam radius.
-
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 Cross-Section 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 Cross-Section 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 Cross-Section 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 Cross-Section Library.
This entry is needed only for I-beams.
Data lines for ARBITRARY sections
- First line
-
Number of segments making up the section.
-
Local 1-coordinate of first point defining the section.
-
Local 2-coordinate of first point defining the section.
-
Local 1-coordinate of second point defining the section.
-
Local 2-coordinate of second point defining the section.
-
Thickness of first segment.
- Second line
-
Local 1-coordinate of next section point.
-
Local 2-coordinate 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 Cross-Section 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 .
- 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 cross-sectional
axis will lie in the plane thus defined, with its positive direction pointing
toward this off-axis 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.
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