# *SECTION_BEAM

LS-DYNA Input Interface KeywordDefines finite element property of beams, trusses, and discrete beams.

## Format

(1) (2) (3) (4) (5) (6) (7) (8)
*SECTION_BEAM
sec_ID ELFORM   NIP CST
If ELFORM = 1 (Integrated beam element), insert the following line.
(1) (2) (3) (4) (5) (6) (7) (8)
TS1
If ELFORM = 2 (Resultant beam element), insert the following line.
(1) (2) (3) (4) (5) (6) (7) (8)
A IYY IZZ IXX
If ELFORM = 2, 3 (Resultant beam element and truss element) with predefined circular section, insert the following line.
(1) (2) (3) (4) (5) (6) (7) (8)
SECTION_08 L1
If ELFORM = 2, 3 (Resultant beam element and truss element) with predefined rectangular section, insert the following line.
(1) (2) (3) (4) (5) (6) (7) (8)
SECTION_11 L2 L1
If ELFORM = 3 (Truss element), insert the following line.
(1) (2) (3) (4) (5) (6) (7) (8)
A
If ELFORM = 6 (Discrete beam element), insert the following line.
(1) (2) (3) (4) (5) (6) (7) (8)
VOL INERTIA CID AREA

## Definition

Field Contents SI Unit Example
sec_ID Section identifier.

(Integer)

ELFORM Beam element formulation.
= 1 (Default)
Integrated beam element.
= 2
Resultant beam element.
= 3
Truss element.
= 6
Discrete beam element
.

(Integer)

NIP Number of integration points (subsections).
= 2 (Default)
CST Cross section type.
= 0
Square section.
= 1
Circular section.
TS1 Cross section dimension.
If CST = 0
Edge of square section.
If CST = 1
Diameter of circular section.

(Real)

$\left[\text{m}\right]$
A Section area.

(Real)

$\left[{\text{m}}^{2}\right]$
IYY, IZZ Area moment of inertia for bending.

(Real)

$\left[{\text{m}}^{4}\right]$
IXX Area moment of inertia for torsion.

(Real)

$\left[{\text{m}}^{4}\right]$
VOL Discrete beam volume.

(Real)

$\left[{\text{m}}^{3}\right]$
INERTIA Discrete mass beam inertia.

(Real)

$\left[\text{kg}\cdot {\text{m}}^{\text{2}}\right]$
CID Coordinate system identifier for DOF directions of the discrete beams.

(Integer)

AREA Section area of cable elements that use *MAT_071.

(Real)

$\left[{\text{m}}^{2}\right]$
L1, L2 Dimension of the predefined section.

(Real)

$\left[\text{m}\right]$