background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
1/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
Organization (S):
EDF-R & D/AMA















Instruction manual
U3.0- booklet: Mesh
Document: U3.01.00



Description of the file of mesh of Code_Aster



Summary:

This file makes it possible to describe a mesh of Code_Aster. It can be built by an automatic interface
between a maillor and the code, but can also be written with the hand. It contains:
·
a possible title,
·
a list of nodes with their co-ordinates,
·
lists of meshs, each mesh is described by the list of the nodes which defines its topology, and sound
orientation,
·
groups of nodes and groups of meshs.

Note:
A concept of the type
mesh,
once read on the file of mesh, can be enriched using operators
of Code_Aster by information which cannot be currently described in the file of
mesh. This relates to in particular the static under-structuring. It is of more possible, now, of
to create groups of nodes or meshs under study.
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
2/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
Tables
matters
1
Structure of the file of mesh ............................................................................................................. 3
2
Structure of under file ..................................................................................................................... 4
2.1
The heading ............................................................................................................................................ 5
2.2
List information ...................................................................................................................... 5
2.3
END of subfile ........................................................................................................................... 5
3
List key words (standard of under files) .......................................................................................... 6
4
The description of the meshs ..................................................................................................................... 7
5
List formats of description .......................................................................................................... 13
5.1
Correspondence Item - Standard FORTRAN ...................................................................................... 13
5.2
FORMAT of reading associated with the key word ........................................................................................ 13
5.3
Repetition of the Format ..................................................................................................................... 13
6
Examples of under file ..................................................................................................................... 14
6.1
File resulting from the interface IDEAS-Aster .......................................................................................... 14
6.2
Example illustrating the possible formats of writing ........................................................................ 14
6.3
Example illustrating the assignment by groups made up ................................................................. 15

background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
3/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
1
Structure of the file of mesh
The file of Aster mesh is read first line until the first occurrence of a line
begin with the word
END
. This key word is obligatory.
The file of Aster mesh consists of a succession of under files of mesh, independent.
UNDER FILE 1
UNDER FILE 2
UNDER FILE NR
END
The file of Aster mesh is a file with format, within the meaning of FORTRAN:
·
the length of line is limited to 80 characters (any information starting from column 81 is
simply been unaware of);
·
the 26 tiny a-z are converted automatically in capital letters,
·
the white character ““and the comma”,” are only the recognized separators,
·
the character % is a character reserved to indicate the beginning, until the end of the line, of one
comment,
·
the numerical data are interpreted in free format:
1 = 1. = 1.0 = 1.E+0 = .1E1 = 10.D-1
The file mesh must contain at least:
·
a subfile of co-ordinates of nodes
COOR_2D
or
COOR_3D
, defined by 2 or 3 numbers
realities in a single orthonormé Cartesian reference mark.
·
a subfile by type of mesh used.
It can contain, moreover, and that is recommended, a subfile
TITRATE
. It is practically
essential to define, at the time of the mesh, the subfiles of groups of meshs
GROUP_MA
and of the subfiles of groups of nodes
GROUP_NO
.
It will be retained that the assignment of a type of finite element, can be done only on one mesh (or
exceptionally on a node for the discrete elements) described in the file mesh.
loadings or the boundary conditions are affected on meshs or nodes according to
case.
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
4/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
2
Structure of under file
Under file starts with a key word and is finished by the key word imposed FINSF:
KEY MOT
.........
.........
FINSF
This description is sufficient for Aster. The most complete description is as follows:
·
each under file comprises 3 parts:
1) the heading of under file,
2) contents of information,
3) the end mark of under file (
FINSF
).
1
3
2
KEY MOT NOM= NBOBJ= NBLIGE= NBLIGT=
NUMIN= NUMAX=
AUTEUR= DATE=
XX/XX/XX
%
COMMENTS




---- INFORMATION ----

FINSF
%
·
MOT
KEY
and
FINSF
(end of under file) are obligatory because they delimit under file with
interior of the file of mesh.
·
NAME
is optional. When the key word is
GROUP_MA
or
GROUP_NO
, if
NAME
misses then
the first character string met after these KEY WORDS will form the NAME of
GROUP_MA
or of
GROUP_NO
.
By convention any character string which follows the characters % is interpreted like one
comment.
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
5/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
2.1 The heading
The role of the heading is to provide total information on the contents of under file:
KEY MOT:
in addition to its role of delimitor of under file it informs about the nature of
information which will follow. It must be in 1ère line of under file and tallied
on the left.
NAME:
it is used to indicate a whole of information. It must be in 1ère line of
the heading of under file. It is optional.
all the other key words are currently ignored by the operator
LIRE_MAILLAGE
[U4.21.01].
2.2
List information
They are the information resulting from a maillor and written in free format.
Information which this file must contain defines of the conventional entities of the method of
finite elements:
·
nodes:
points defined by a name and their Cartesian co-ordinates in
space 2D or 3D,
·
meshs:
plane or voluminal named topological figures (not, segment,
triangle, quadrangle, tetrahedron,…), defined by the ordered list of the nodes
who constitute them and to whom will be able to apply various types
finite elements, boundary conditions or loadings. The command of
nodes directs the mesh. This orientation must be scrupulously established
because it is in particular used to lay down the orientation of the loadings
(pressure,…).
One can also define groups of these topological entities.
·
groups of nodes: named lists of names of nodes,
·
groups of meshs: named lists of names of meshs.
Systematically, when one has to refer to nodes (or meshs), one will be able to make
reference to groups of nodes (or groups of meshs).
The interfaces with the mailleurs automatically generate such groups (according to criteria
clean with the maillor).
These groups facilitate the assignment of the material characteristics on the mesh, of the conditions
with the limits or the impression of the results. Indeed, at the time of such operations one refers to the nodes
or with the meshs, which it is interesting to describe by group.
The operator of Code_Aster
DEFI_GROUP
[U4.22.01] allows to create groups a posteriori on all
concept of the type
mesh
already read.
It will be noted, that all entities handled in the code (nodes, meshs, groups of nodes,
groups of meshs) are named and usable constantly by their name (8 characters with
maximum). The classification of the entities is never clarified: it is useful only in-house for
to point on the values of the various associated variables.
2.3
END of subfile
It is reserved” and obligatory word the “
FINSF
who indicates the end of under file, which begin with one
MOT
KEY
.
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
6/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
3
List key words (standard of under files)
TITRATE
Description of the file mesh in documentary matter. Operators
of interface with mailleurs build a title starting from information
clean with each maillor
/COOR_3D
Description of the nodes by three space co-ordinates:
·
name of the node described (or number interpreted like a name),
·
3 co-ordinates,
/
COOR_2D
Description of the nodes by 2 co-ordinates
:
·
name of the node described (or number interpreted like a name),
·
2 co-ordinates,
/POI1 points
)
/
SEG2/
SEG3/
SEG4 segments
)
/
TRIA3
/
TRIA6
/
TRIA7
triangles
)
/
QUAD4
/
QUAD8
/
QUAD9
quadrangles
)
connectivity
/
HEXA8
/
HEXA20
/
HEXA27
hexahedrons
) of
meshs
/
PENTA6
/
Pentahedral PENTA15)
/
TETRA4
/
TETRA10 tetrahedrons)
/
PYRAM5
/
PYRAM13 pyramids
)
GROUP_MA Groups meshs (attention the name is obligatory)
GROUP_NO Groups nodes (attention the name is obligatory)
Note:
·
When a key word was read, there remains interpreted until the appearance of
FINSF
.
·
After a FINSF, any key word not recognized (typing error) is ignored and a message is
emitted.
·
COOR_2D and COOR_3D are mutually exclusive.
·
The presence of a frame of reference in universal file IDEAS causes a stop
interface IDEAS/Aster.
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
7/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
4
The description of the meshs
Conventions of description of the topology of the meshs in Aster are summarized here. The use
meshs is given here as an indication, it is necessary to refer to documentation suitable for each
order.
Net associated with a node (2D or 3D)


POI1

1

Net associated with a segment (2D or 3D)
SEG2

1
2
SEG3
1
2
3
SEG4


Orientation:
The orientation is laid down by the command of the nodes nodes
1
2
This orientation is possibly supplemented by characteristics given according to
the type of affected finite element on the mesh by the key word factor
ORIENTATION
of
the operator
AFFE_CARA_ELEM
[U4.42.01].
1
4
3
2
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
8/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
Net associated with a triangle (2D or 3D)



TRIA3
2
3
1

TRIA6
1
4
2
3
5
6

TRIA7







Orientation:
The orientation is laid down by the command of the nodes nodes which are given to define it
direct trigonometrical direction.
2
3
1
normal external with the mesh
This orientation is possibly supplemented by characteristics given to
elements by the operator
AFFE_CARA_ELEM
[U4.42.01], in particular for the elements of
hull by the key word factor
HULL
.
1
4
2
3
5
6
7
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
9/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
Net associated with a quadrangle
(2D or 3D)


QUAD4
1
4
2
3


QUAD8
6
3
1
2
4
5
8
7


QUAD9
9
6
3
1
2
4
5
8
7

Orientation:
The orientation is laid down by the command of the nodes nodes which are given to define it
direct trigonometrical direction
2
3
4
normal external with the mesh
1
This orientation is possibly supplemented by characteristics given to
elements by the operator
AFFE_CARA_ELEM
[U4.42.01], in particular for the elements of
hull by the key word factor
HULL
.


background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
10/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
Net associated with a tetrahedron (3D)




TETRA4
1
2
3
4




TETRA10
1
2
4
5
6
7
8
9
10
3
Net associated with a pyramid (3D)




PYRAM5
1
2
3
4
5




PYRAM13
13
5
4
8
3
7
2
6
1
10
11
9
12

background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
11/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
Net associated with a pentahedron (3D)




PENTA6
1
2
3
4
5
6




PENTA15
1
2
4
5
6
7
9
8
10
11
12
13
14
15
3
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
12/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A

Net associated with a hexahedron (3D)




HEXA8
1
3
5
6
7
8
4
2




HEXA20
1
2
3
5
6
7
8
9
10
11
12
4
13
14
15
16
17
18
19
20








HEXA27
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
2
1
3
4
5
6
7
8
11
21
22
23
24
25
26
27
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
13/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
5
List formats of description
We will describe the format of description of information by a continuation of items.
5.1
Correspondence Item - Standard FORTRAN
NOM_DE_NOEUD
CHARACTER * 8
NOM_DE_MAILLE
CHARACTER * 8
COORD
REAL * 8
LIGNE_DE_TEXTE
CHARACTER * 80

5.2
FORMAT of reading associated with the key word
FORMATS recognized by Aster
key word
(1 * NOM_DE_NOEUD, 3 * COORD)
(1 * NOM_DE_NOEUD, 2 * COORD)
COOR_3D
COOR_2D
(1 * NOM_DE_MAILLE, 1 * NOM_DE_NOEUD) POI1
(1 * NOM_DE_MAILLE, 2 * NOM_DE_NOEUD) SEG2
(1 * NOM_DE_MAILLE, 3 * NOM_DE_NOEUD) SEG3, TRIA3
(1 * NOM_DE_MAILLE, 4 * NOM_DE_NOEUD) QUAD4, TETRA4, SEG4
(1 * NOM_DE_MAILLE, 5 * NOM_DE_NOEUD) PYRAM5
(1 * NOM_DE_MAILLE, 6 * NOM_DE_NOEUD) TRIA6, PENTA6
(1 * NOM_DE_MAILLE, 7 * NOM_DE_NOEUD) TRIA7
(1 * NOM_DE_MAILLE, 8 * NOM_DE_NOEUD) QUAD8, HEXA8
(1 * NOM_DE_MAILLE, 9 * NOM_DE_NOEUD) TRIA9
(1 * NOM_DE_MAILLE, 10 * NOM_DE_NOEUD) TETRA10
(1 * NOM_DE_MAILLE, 13 * NOM_DE_NOEUD) PYRAM13
(1 * NOM_DE_MAILLE, 15 * NOM_DE_NOEUD) PENTA15
(1 * NOM_DE_MAILLE, 20 * NOM_DE_NOEUD) HEXA20
(1 * NOM_DE_MAILLE, 27 * NOM_DE_NOEUD) HEXA27
(1 * NOM_DE_NOEUD) GROUP_NO
(1 * NOM_DE_MAILLE) GROUP_MA
(LIGNE_DE_TEXTE)
TITRATE
5.3
Repetition of the Format
·
Any repetition of the format must start at the beginning of line.
Examples:
Is ILLICIT:
COOR_2D
N1 1.
2.
N2 1.
3.
FINSF
Is LICIT:
COOR_2D
N1 1.
2.
N2 1.
3.
FINSF
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
14/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
6
Examples of under file
Examples of under files describing the space co-ordinates of 5 nodes expressed in the reference mark
total Cartesian basic. Here the contents of information is the same one for the 2 pennies files, it is it
mode of representation which differs.
6.1
File resulting from the interface IDEAS-Aster
COOR_3D NOM=MAILLAGE1
NBOBJ=5 NBLIGE=5
NBLIGT=12
NUMIN=4 NUMAX=14
AUTEUR=INTERF_ST/TF
DATE=27/11/89
%
XMAX=10.0
YMAX=20.0
ZMAX=0.0
%
XMIN=0.0
YMIN=0.0
ZMIN=0.0
% FORMAT= (1 * NOM_DE_NOEUD, 3 * COORD)
NO4
0.0 0.0
0.0
NO7
5.0 0.0
0.0
NO8
5.0 5.0
0.0
NO10
10.0 20.0
0.0
NO14
5.0 10.0 0.0
FINSF
6.2
Example illustrating the possible formats of writing
TITRATE
%
it is
titrate
THAT IT IS BEAUTIFUL MY FILE MESH
% self-satisfaction
FINSF
COOR_2D %
co-ordinates
2D
%
presentation
licit
but
little
advisable
NOEUD1
0
0.0
NOEUD2
1
1.D+0
NOEUD3
2.213564
2.32E+00
FINSF
SEG 2%
some
meshs
MAILLE1 NOEUD1
NOEUD2
%
who
suits me
MAILLE3 NOEUD2
NOEUD3
FINSF
POI1
MAILLE2 NOEUD2
FINSF
GROUP_MA
%
group
of
meshs
GROUP1
MAILLE1 MAILLE3
FINSF
GROUP_NO
NAME
=
GROUP2
NOEUD1
NOEUD2
FINSF
END
%
obligatory
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
15/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A
6.3
Example illustrating the assignment by groups made up
This example is, obviously, diagrammatic to describe the main rules of assignment.
Mesh 2D: a quarter of a plane field
8
6
4
2
2
4
6
8
N1
N3
N5
N7
N9
N2
N4
N6
N8
N10
N01
N02
N03
m1
m5
m2
m3
m4
m6
m7
m8
m9
m10
be3
be2
be1
be4
bi1
bi2
1

For the assignment of

·
loadings on the edges
interior and outside:
groups of meshs
BORD_EXT and BORD_INT

·
boundary conditions:
groups of nodes SYME1
and SYME2

·
materials:
groups of meshs
mail1 and mail2
COOR_2D
N1 4. 2.
N2 2. 4.
N3 6. 2.
N4 2. 6.
N5 8. 2.
N6 2. 8.
N7 6. 3.8
N8 3.8 6.
N9 8. 4.
N10 4. 8.
N01 3. 3.
N02 5. 5.
N03 7. 7.
FINSF
GROUP_MA name = BORD_INT
bi1 bi2
FINSF
GROUP_MA name = BORD_EXT
Be 1be2 be3 be4
FINSF
GROUP_NO name = SYME1
N1 N3 N5
FINSF
GROUP_NO name = SYME2
N2 N4 N6
FINSF
GROUP_MA name = mail1
m5 m6 m7
FINSF
GROUP_MA name = mail2
m8 m9 m10
FINSF
TRIA3
m2 N01 N7 N02
m3 N01 N02 N8
m6 N7 N9 N03
m7 N7 N03 N02
m8 N8 N02 N03
m9 N8 N03 N10
FINSF
QUAD4
m1 N1 N3 N7 N01
m5 N3 N5 N9 N7
m4 N2 N01 N8 N4
m10 N4 N8 N10 N6
FINSF
SEG2 name = B_INT
bi1 N1 N01
bi2 N01 N2
FINSF
SEG2 name = B_EXT
be1 N5 N9
be2 N9 N03
be3 N03 N10
be4 N10 N6
FINSF
END
background image
Code_Aster
®
Version
7.4
Titrate:
Description of the file of mesh of Code_Aster
Date:
06/06/05
Author (S):
J. PELLET
Key
:
U3.01.00-D
Page
:
16/16
Instruction manual
U3.0- booklet: Mesh HT-66/05/004/A

























Intentionally white left page.