background image
Code_Aster
®
Version
7.4
Titrate:
Modelings
3D
and
3d_SI
mechanics
Date:
01/06/05
Author (S):
X. DESROCHES
,
F. LEBOUVIER
Key
:
U3.14.01-E
Page
:
1/4
Instruction manual
U3.14 booklet: Mechanical finite elements 3D
HT-66/05/004/A
Organization (S):
EDF-R & D/AMA, DeltaCAD















Instruction manual
U3.14 booklet: Mechanical finite elements 3D
U3.14.01 document



Modelings
3D
and
3d_SI
mechanics



Summary:

This document describes for mechanical modelings
3D
and
3d_SI
:
·
degrees of freedom carried by the finite elements which support modeling,
·
the related meshs supports,
·
supported loadings,
·
nonlinear possibilities,
·
case-tests implementing modeling.

Modelings
3D
and
3d_SI
(Phenomenon:
MECHANICS
) correspond to finite elements of which meshs
supports are voluminal.

The suffix
_SI
mean: Under - Integrated: the integration of the terms relating to the laws of behavior is done
reduced way (diagram of points of Gauss of a nature less low than modeling with complete integration).
background image
Code_Aster
®
Version
7.4
Titrate:
Modelings
3D
and
3d_SI
mechanics
Date:
01/06/05
Author (S):
X. DESROCHES
,
F. LEBOUVIER
Key
:
U3.14.01-E
Page
:
2/4
Instruction manual
U3.14 booklet: Mechanical finite elements 3D
HT-66/05/004/A
1 Discretization
1.1
Degrees of freedom
Modeling
Degrees of freedom
(with each node node)
3D, 3d_SI
DX
: following displacement
X
DY
: following displacement
Y
DZ
: following displacement
Z

1.2
Net support of the matrices of rigidity
The meshs support of the finite elements can be tetrahedrons, pyramids, prisms or
hexahedrons. The elements are isoparametric.
Modeling Nets Interpolation
Remarks
3D, 3d_SI
TETRA4
Linear
3D, 3d_SI
TETRA10
Quadratic
3D, 3d_SI
PYRAM5
Linear
3D, 3d_SI
PYRAM13
Quadratic
3D, 3d_SI
PENTA6
Bilinear
3D, 3d_SI
PENTA15
Serendip
3D, 3d_SI
HEXA8
Trilinear
3D HEXA20
Serendip integration
complete
3d_SI HEXA20
Serendip integration
reduced
3D, 3d_SI
HEXA27
Tri-quadratic

1.3
Net support of the loadings
Modeling Nets Interpolation
Remarks
3D, 3d_SI
TRIA3
Linear or
Bilinear
TRIA6
Quadratic or
Serendip
QUAD4
Bilinear
QUAD8
Serendip
QUAD9
Quadratic

background image
Code_Aster
®
Version
7.4
Titrate:
Modelings
3D
and
3d_SI
mechanics
Date:
01/06/05
Author (S):
X. DESROCHES
,
F. LEBOUVIER
Key
:
U3.14.01-E
Page
:
3/4
Instruction manual
U3.14 booklet: Mechanical finite elements 3D
HT-66/05/004/A
2 Loadings
supported
The loadings available are as follows:
·
“CONTACT”
Allows to define the areas subjected to conditions of contact.
Supported modelings:
3D
,
3d_SI
·
“FORCE_ARETE”
Allows to apply linear forces, with an edge of voluminal element.
Supported modelings:
3D
,
3d_SI
·
“FORCE_FACE”
Allows to apply surface forces to a voluminal face of element.
Supported modelings:
3D
,
3d_SI
·
“FORCE_INTERN”
Allows to apply voluminal forces.
Supported modelings:
3D
,
3d_SI
·
“GRAVITY”
Allows to apply a loading of the gravity type.
Supported modelings:
3D
,
3d_SI
·
“PRES_REP”
Allows to apply a pressure to a field of continuous medium.
Supported modelings:
3D
,
3d_SI
·
“TEMP_CALCULEE”
Allows to apply a thermal loading.
Supported modelings:
3D
,
3d_SI
·
“SECH_CALCULEE”
Allows to apply a field of drying.
Supported modelings:
3D
,
3d_SI
·
“HYDR_CALCULEE”
Allows to apply a field of hydration and a field of temperature.
Supported modelings:
3D
,
3d_SI
·
“EPSA_CALCULEE”
Allows to apply a field of anelastic deformations resulting from external software.
Supported modelings:
3D
,
3d_SI
·
“PRES_CALCULEE”
Allows to apply a field of pressure resulting from external software.
Supported modelings:
3D
,
3d_SI
background image
Code_Aster
®
Version
7.4
Titrate:
Modelings
3D
and
3d_SI
mechanics
Date:
01/06/05
Author (S):
X. DESROCHES
,
F. LEBOUVIER
Key
:
U3.14.01-E
Page
:
4/4
Instruction manual
U3.14 booklet: Mechanical finite elements 3D
HT-66/05/004/A
·
“EPSI_INIT”
Allows to apply a field of initial deformation.
Supported modelings:
3D
,
3d_SI
·
“ROTATION”
Allows to apply a rotational speed and a vector of rotation.
Supported modelings:
3D
,
3d_SI
·
“EFFE_FOND”
Allows to calculate and apply the basic effect on a branch of piping subjected to one
internal pressure.
Supported modelings:
3D
,
3d_SI

3 Possibilities
non-linear
3.1
Laws of behaviors
Laws of behaviors (model conventional, model buildings with damage, models
for the concrete and the grounds,…), usable under
COMP_INCR
or under
COMP_ELAS
in
STAT_NON_LINE
and
DYNA_NON_LINE,
under the key word
RELATION,
are described in details in the document
“Behavior nonlinear” [U4.51.11].
3.2 Deformations
Deformations usable under
COMP_INCR
or under
COMP_ELAS
in
STAT_NON_LINE
and
DYNA_NON_LINE
, under the key word
DEFORMATION
, are described in details in the document
“Behavior nonlinear” [U4.51.11].

4
Examples of implementation: case-tests
·
3D
­ Statique
linear
FORMA01C [V7.15.100]: Quasi-static analysis of a piping comprising an elbow
subjected to a specific force, an internal pressure and a thermal transient.
­ Statique
non-linear
HSNV121A: [V7.15.121]: Quasi-static analysis in great deformations of a bar under
thermal loading subjected to a force of traction.
­ Dynamique
linear
SDLV100A [V2.04.100]: Seek frequencies and modes of bending associated with one
slim beam of variable rectangular section (embed-free).
­ Dynamique
non-linear
SDNV100A [V5.03.100]: Analyze transitory direct of a slim beam animated of one
initial speed coming to run up against a rigid wall.
·
3d_SI
­ Statique
non-linear
HSNV125D: Quasi-static analysis of a volume in traction subjected to a temperature
variable and with a loading in shearing with a law of viscoplastic behavior
(case-test n°2 PHI2AS “non-linear Behavior of materials”, 2000 ­ Volume XXIV ­
N°1).
­ Dynamique
non-linear
SDNV103A [V5.03.103]: Analyze impact of an elastoplastic bar of Taylor on one
rigid solid mass. Modeling takes into account the contact with friction and one
behavior elastoplasticity with great deformations.