/PROP/TYPE18 (INT_BEAM)
Block Format Keyword Describes the integrated beam property set. This beam model is based on Timoshenko theory and takes into account transverse shear strain without warping in torsion.
It can be used for deep beam cases (short beams). Beam section and position of integration points can be either used as predefined or prescribed directly.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
/PROP/TYPE18/prop_ID/unit_ID or /PROP/INT_BEAM/prop_ID/unit_ID | |||||||||
prop_title | |||||||||
Isect | Ismstr | ||||||||
dm | df | ||||||||
NIP | Iref | Y0 | Z0 |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
Yi | Zi | Area |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
NITR | L1 | L2 | L3 | L4 | |||||
L5 | L6 |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
Definition
Field | Contents | SI Unit Example |
---|---|---|
prop_ID | Property
identifier. (Integer, maximum 10 digits) |
|
unit_ID | Unit identifier. (Integer, maximum 10 digits) |
|
prop_title | Property
title. (Character, maximum 100 characters) |
|
Isect | Section type. 5
(Integer) |
|
Ismstr | Small strain option flag.
(Integer) |
|
dm | Beam membrane
damping. Default = 0.00 (Real) |
|
df | Beam flexural
damping. Default = 0.01 (Real) |
|
NIP | Number of integration
points (subsections). Only for Isect =0; otherwise, NIP=0. (Integer) |
|
Iref | Subsection center
reference flag. Only for Isect =0.
(Integer) |
|
Y0 | Local Y coordinate of the
section center. Only for Isect =0. (Real) |
|
Z0 | Local Z coordinate of the
section center. Only for Isect =0. (Real) |
|
Yi | Local Y coordinate of the
integration point. (Real) |
|
Zi | Local Z coordinate of the
integration point. Only for Isect =0. (Real) |
|
Area | Area of the subsection.
Only for Isect =0. (Integer) |
|
NITR | Option for integration
points in predefined section for
Isect >
0. 5. Default = 2 if (1 ≤ Isect ≤ 5) Default = 0 if (Isect ≥ 10). (Integer) |
|
L1 | First size of the
predefined section for
Isect >
0. 5 (Real) |
|
L2 | Second size of the
predefined section for
Isect >
0. 5 Default = L1 for Isect = 1 or 3 (Real) |
|
L3 | Third size of the predefined section for Isect > 0. | |
L4 | Fourth size of the predefined section for Isect > 0. | |
L5 | Fifth size of the predefined section for Isect > 0. | |
L6 | Sixth size of the predefined section for Isect > 0. | |
Rotation DOF code of nodes
1 and 2 (see detail input below). (6 Booleans) |
Detail of Rotation DOF Input Fields for Nodes 1 and 2
(1)-1 | (1)-2 | (1)-3 | (1)-4 | (1)-5 | (1)-6 | (1)-7 | (1)-8 | (1)-9 | (1)-10 |
---|---|---|---|---|---|---|---|---|---|
Definition
Field | Contents | SI Unit Example |
---|---|---|
= 1 Rotation DOF about X
at node 1 is released. (Boolean) |
||
= 1 Rotation DOF about Y
at node 1 is released. (Boolean) |
||
= 1 Rotation DOF about Z
at node 1 is released. (Boolean) |
||
= 1 Rotation DOF about X
at node 2 is released. (Boolean) |
||
= 1 Rotation DOF about Y
at node 2 is released. (Boolean) |
||
= 1 Rotation DOF about Z
at node 2 is released. (Boolean) |
Example 1 (Integrated Beam)
#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/2
unit for prop
Mg mm s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#- 2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PROP/TYPE18/4/2
Integrated beam - bXh=10X10 with 4 integration points (subsections)
# Isect Ismstmr
0 0
# dm df
0 0
# NIP Iref Y0 Z0
4 1 0 0
# Y Z Area
2.5 2.5 25
2.5 -2.5 25
-2.5 2.5 25
-2.5 -2.5 25
# OmegaDOF
000 000
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
Example 2 (Integrated Beam)
#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/2
unit for prop
Mg mm s
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#- 2. MATERIALS:
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/PROP/TYPE18/4/2
Integrated beam - 4 integration points in predefined section bXh=10X10
# Isect Ismstmr
1 0
# dm df
0 0
# NIP Iref Y0 Z0
0 1 0 0
# NITR L1 L2 L3 L4
2 10 10 0 0
# L5 L6
0 0
# OmegaDOF
000 000
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#ENDDATA
/END
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
Comments
- Small strain formulation is activated from time t=0, if Ismstr =1. It may be used for a faster preliminary analysis because is constant, but the accuracy of results is not ensured.
- If Ismstr =1, the
strains and stresses which are given in material laws are engineering strains
and stresses. Time history output returns true strains and stresses.
Figure 1.
- The cross-section of
the element is defined using up to 100 integration points (Figure 2). The element properties of the cross-section,
that is, area moments of inertia and area, are computed by Radioss as:
- It can be used for
deep beam cases (short beams). The use of several integration points in the
section allows to get an elasto-plastic model in which von Mises criteria is
written on each integration point and the section can be partially plastified
contrary to the classical beam element (TYPE3). Compatible with material LAW1, LAW2, LAW36 and LAW44. However,
as the element has only one integration point in its length, it is not
recommended to use a single beam element per line of frame structure in order to
take into account the plasticity progress in length, as well as in depth.
Figure 2. Cross-section Definitions in the Integrated Beam
- Predefined
cross-sections are available (circular or rectangular). Number of integration
points in the section is prescribed via NITR depending on
Isect and the chosen quadrature:
- For Isect =
1 and 2. Integration points are
distributed uniformly across the section according to the section type
and NITR.
Figure 3.
- For Isect =
3. The section is rectangular, the distribution of
the integration points corresponds to the Gauss-Lobatto quadrature with
points on the edge. IP =
NITR*NITR. The maximum
NITR possible is 9 corresponding to 81
integration points.
Figure 4.
- For Isect =
4. The section is circular. The distribution of the
integration points radially corresponds to Gauss-Lobatto quadrature with
points on edge. Three options: NITR =
1, NITR = 17
and NITR = 25. Here the number of
integration points is equal to NITR.
Figure 5.
- For Isect =
5. The section is circular. Three options:
NITR = 1,
NITR = 9 and
NITR = 17. Here the number of integration
points is equal to NITR.
Figure 6.
- For Isect ≥
10. The predefined section is defined with
dimensions L1 to L6 and the number
of integration points NITR defined between 0 to
maximum value NITR_max (number of integrations points
is limited to 100). Here is the list of required dimensions and maximum value of NITR for each predefined section:
Table 1. Isect Shape (presented with NITR = 2) NITR_max Number of integration points (≤ 100) Isect = 10 15 Isect = 11 30 Isect = 12 47 Isect = 13 22 Isect = 14 23 Isect = 15 30 Isect = 16 7 Isect = 17 2 Isect = 18 2 Isect = 19 15 Isect = 20 7 Isect = 21 8 Isect = 22 14 Isect = 23 8 Isect = 24 10 Isect = 25 22 Isect = 26 15 Isect= 27 11 Isect= 28 23 Isect= 29 4 Isect= 30 8 Isect= 31 5
- For Isect =
1 and 2. Integration points are
distributed uniformly across the section according to the section type
and NITR.