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Code_Aster
®
Version
7.4
Titrate:
Modeling
POU_D_T_GD
Date:
01/06/05
Author (S):
J.L. FLEJOU, F. LEBOUVIER
Key
:
U3.11.05-C
Page
:
1/4
Instruction manual
U3.11 booklet: Mechanical elements of structure 1D
HT-66/05/004/A
Organization (S):
EDF-R & D/AMA, DeltaCAD















Instruction manual
U3.11 booklet: Mechanical elements of structure 1D
Document: U3.11.05



Modeling
POU_D_T_GD



Summary:

This document describes for modeling
POU_D_T_GD
:
·
degrees of freedom carried by the finite elements which support modeling,
·
the related meshs supports,
·
supported loadings,
·
nonlinear possibilities,
·
case-tests implementing modeling.

Modeling
POU_D_T_GD
corresponds to a formulation of elements of beams of fascinating Timoshenko in
count great displacements and great rotations (cf [R5.03.40]).

It is usable for problems of three-dimensional beams in isotropic mechanical analysis and in
linear elastic behavior.
background image
Code_Aster
®
Version
7.4
Titrate:
Modeling
POU_D_T_GD
Date:
01/06/05
Author (S):
J.L. FLEJOU, F. LEBOUVIER
Key
:
U3.11.05-C
Page
:
2/4
Instruction manual
U3.11 booklet: Mechanical elements of structure 1D
HT-66/05/004/A
1 Discretization
1.1
Degrees of freedom
The degrees of freedom are, in each node of the mesh support, the six components of displacement
(three translations and three rotations).
Finite element
Degrees of freedom (with each node node)
POU_D_T_GD DX
DY
DZ
DRX
DRY
DRZ
1.2
Net support of the matrices of rigidity
The meshs support of the finite elements, in displacement formulation, are segments with two nodes
SEG2
:
Modeling Nets Element
finished
Remarks
POU_D_T_GD SEG2
MECA_POU_D_T_GD

2
Assignment of the characteristics
For these elements of structures 1D, it is necessary to affect geometrical characteristics which
are complementary to the data of mesh. The definition of these data is carried out with
order
AFFE_CARA_ELEM
associated the key words following factors:
·
BEAM
Allows to define and affect the characteristics of the cross section.
·
ORIENTATION
Allows to define and affect the main axes of the cross sections of the elements of
beam type.

3 Loadings
supported
Loadings specific, available in
AFFE_CHAR_MECA
are as follows:
·
“EPSI_INIT”
Allows to apply a loading of initial deformation.
·
“FORCE_POUTRE”
Allows to apply linear forces.
·
“GRAVITY”
Allows to apply a loading of the gravity type.
·
“TEMP_CALCULEE”
Allows to apply a thermal loading.
·
“INTE_ELEC”
Allows to apply the force of LAPLACE acting on a main conductor, due to
presence of a secondary conductor not necessarily right compared to this conductor
the main thing.
background image
Code_Aster
®
Version
7.4
Titrate:
Modeling
POU_D_T_GD
Date:
01/06/05
Author (S):
J.L. FLEJOU, F. LEBOUVIER
Key
:
U3.11.05-C
Page
:
3/4
Instruction manual
U3.11 booklet: Mechanical elements of structure 1D
HT-66/05/004/A
4 Possibilities
non-linear
4.1
Law of behaviors
The law of behavior specific to this modeling, usable under
COMP_ELAS
in
STAT_NON_LINE
and
DYNA_NON_LINE
is the relation
ELAS_POUTRE_GR
(Cf [U4.51.11]).

4.2 Deformations
Only deformation '
GREEN_GR
'allowing to treat the beams in great displacements and in
great rotations is available (cf [U4.51.11]). Deformations used in the relation of
behavior are the deformations of GREEN-LAGRANGE.


5
Examples putting work modeling: case-test
·
Non-linear statics
SSNL103A [V6.02.103]: Calculation of the static deformation in great displacements and large
rotations of a beam fixed at an end and subjected to one bending moment to the other
end.
·
Non-linear dynamics
SDNL103A [V5.02.103]: Analyze response of a gantry embedded in feet and subjected to one
force dynamic applied in the middle of its span and perpendicular to its plan.
background image
Code_Aster
®
Version
7.4
Titrate:
Modeling
POU_D_T_GD
Date:
01/06/05
Author (S):
J.L. FLEJOU, F. LEBOUVIER
Key
:
U3.11.05-C
Page
:
4/4
Instruction manual
U3.11 booklet: Mechanical elements of structure 1D
HT-66/05/004/A


























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