Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
1/14
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U7.0- booklet: Data exchanges
HT-62/06/004/A
Organization (S):
EDF-R & D/SINETICS
Instruction manual
U7.0- booklet: Data exchanges
Document: U7.03.01
Macro-control
MACR_ADAP_MAIL
1 Goal
To adapt a mesh with the software LOBSTER.
This operation is placed after the first calculation on a formed mesh of segments, mesh-points,
triangles, quadrangles, tetrahedrons. An indicator of the error will have been calculated. According to its value
net by mesh, the software LOBSTER will modify the mesh. It is also possible to interpolate
fields with the nodes or constant by elements of the old mesh towards the new one.
One can connect calculation and adaptation progressively process of improvement of calculation.
However, this process cannot be stopped then begun again by a “CONTINUATION”. All must have
place on the way.
The software LOBSTER
is presented on the site:
http://www.code-aster.org/outils/homard
One finds a description of the technique used there to modify the mesh as well as
examples.
To know some more about LOBSTER, one can refer to the documents quoted in bibliography.
Code_Aster
®
Version
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Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
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G. NICOLAS
Key
:
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2 Syntax
MACR_ADAP_MAIL (
# characteristic of the adaptation
ADAPTATION =
_F (
# choice of the type of adaptation
/FREE =/“RAFF_DERA”
/
“REFINEMENT”
/
“DERAFFINEMENT”
/UNIFORM =/“REFINEMENT”
/
“DERAFFINEMENT”
/
“NOTHING”
# mesh to be modified
MAILLAGE_N = man
[mesh]
# new mesh
MAILLAGE_NP1
=
Co
(manp1)
[K8]
# If the adaptation is free
# choice of the structure containing the indicator
/
RESULTAT_N =
resun
[evol_elas]
[evol_thme]
[evol_noli]
[evol_ther]
INDICATOR =
indic
[K16]
/
CHAM_GD =
cham_gd_i
[cham_gd]
NOM_CMP_INDICA = cmp
[K8]
Selection of the temporal parameter
/
NUME_ORDRE
=
command
[I]
/
INST
=
moment
[R]
I
PRECISION
=
/
prec [R]
/
1.0E-3
[DEFECT]
I CRITERION =/“RELATIVE”
[DEFECT]
/
“ABSOLUTE”
#
If
refinement
/CRIT_RAFF_PE
= crp
[R]
/
CRIT_RAFF_REL
=
crr
[R]
/
CRIT_RAFF_ABS
=
CRA
[R]
#
Finsi
#
If
déraffinement
/CRIT_DERA_PE
= cdp
[R]
/
CRIT_DERA_REL
=
cdr
[R]
/
CRIT_DERA_ABS
=
half-value layer
[R]
#
Finsi
#
Finsi
# If refinement, free or uniform
NIVE_MAX
=
nivmax
[I]
#
Finsi
# So déraffinement, free or uniform
NIVE_MIN
=
nivmin
[I]
# Finsi
)
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
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Instruction manual
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HT-62/06/004/A
#
Follow-up of a border
MAILLAGE_FRONTIERE
=
maf
[mesh]
GROUP_MA
=
l_grma [l_gr_maille]
# Updated of fields on the new mesh
MAJ_CHAM = _F (
# choice of the structure containing the field to be updated
/
RESULT
=
resu [evol_elas]
[evol_thme]
[evol_noli]
[evol_ther]
NOM_CHAM
=
nomsymb [K16]
/
CHAM_GD =
cham_gd [cham_gd]
Selection of the temporal parameter
/
NUME_ORDRE
=
command
[I]
/
INST
=
moment
[R]
I
PRECISION
=
/
prec [R]
/
1.0E-3
[DEFECT]
I CRITERION =/“RELATIVE”
[DEFECT]
/
“ABSOLUTE”
CHAM_MAJ
=
Co
(chpmaj)
[K8]
TYPE_CHAM
=/“NOEU_TEMP_R”
/“NOEU_DEPL_R”
/
etc
…
)
NON_SIMPLEXE =/
0
/1
/
2
[DEFECT]
NUMBERS
=
/
“YES”
[DEFECT]
/
“NOT”
QUALITY =/
“YES”
/
“NOT”
[DEFECT]
CONNEXITY
=/“YES”
/
“NOT”
[DEFECT]
CUT
=
/
“YES”
/
“NOT”
[DEFECT]
INTERPENETRATION
=/“YES”
/
“NOT”
[DEFECT]
LANGUAGE
=
/
“FRENCH” [DEFECT]
“FRENCH”
“ENGLISH”
“ENGLISH”
VERSION_HOMARD
=
/
“V7_7”
[DEFECT]
/
“V7_N'
/
“V7_N_PERSO”
INFORMATION =
/
1
[DEFECT]
/2
);
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
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G. NICOLAS
Key
:
U7.03.01-D1
Page:
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3
Description of an adaptation of mesh
3.1
General outline of an adaptation
The principle of a calculation with adaptation of mesh is as follows:
Phase 1:
Reading of the initial mesh, m0
Definition of materials
Phase 2:
·
definition of the model, the loadings on this mesh m0
·
mechanical calculation producing a resu0 result
·
calculation of an indicator of error, ERR0
This initial phase is the standard phase of any calculation
Phase 3:
Adaptation. One recovers a new mesh, m1
Phase 4:
·
definition of the model, the loadings on the mesh m1,
·
mechanical calculation producing a resu1 result,
·
calculation of an indicator of error, ERR1.
Phase 4 is the copy of phase 2. The only thing which changed is the mesh. So all them
concepts while depending must be taken again. Today, there is no possibility nor of re-using them
old concepts, nor to destroy them automatically.
Then, one can continue, as many once as one wants, the tandem phase 3/phase 4. In the absence of
structure of loop in the process control language, the user must duplicate itself them
instructions.
See the reference [bib1] for a general presentation of the adaptation of mesh and LOBSTER,
accompanied by examples.
Caution:
This sequence of calculations and adaptations should not be stopped then begun again by one
“CONTINUATION”.
3.2
Operation of the macro-control
Phase 3 carries out the adaptation of the mesh. It is activated by the macro-control
MACR_ADAP_MAIL, described in this document. It has as an essential argument the name of the concept of
mesh running and the name which one will give to the concept of the future mesh. The other obligatory data
is the type of adaptation which one wishes: free, i.e. according to the values which one takes
indicator of error on the elements of the mesh, or uniform, i.e. all the elements are
treaties in the same way.
The other data depend then on the options selected.
In complement with the adaptation, LOBSTER can provide on request of the assessments on the quality of
elements of the mesh, the connexity of the field of calculation, sizes characteristic or a control of
noninterpenetration of the elements. This information is obtained by the activation of the key words
associated.
In a general way, the essential impressions provided by LOBSTER are inserted in the file
“mess” with the execution. In the event of error, or in mode of information 2, more detailed impressions have
place.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
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4 Operands
4.1 Key word
ADAPTATION
ADAPTATION = _F (
This operand makes it possible to define the type of adaptation wished. The selection is done initially among
two types: free or uniform.
4.1.1 Operand
FREE
/FREE
=/“RAFF_DERA”
/
“REFINEMENT”
/
“DERAFFINEMENT”
This operand is employed to make free adaptation of a mesh. In other words,
the decision of (die) refining an element is caught according to the value of an indicator
of error calculated before.
The choice can be done between three alternatives:
·
“RAFF_DERA”: the mesh is refined and déraffiné according to the indicator
of error,
·
“REFINEMENT”: only the function of refinement is activated. Elements with
low level of error are not déraffinés,
·
“DERAFFINEMENT”: it is the reverse, only the function of déraffinement is activated.
The elements on high level of error are not refined.
4.1.2 Operand
UNIFORM
/UNIFORM
=/“REFINEMENT”
/
“DERAFFINEMENT”
/
“NOTHING”
This operand is employed to make a uniform adaptation of a mesh. In others
terms, all the elements of the mesh are treated same manner, without holding account
of an indicator of error. The choice can be done between three alternatives:
·
“REFINEMENT”: all the elements are refined,
·
“DERAFFINEMENT”: all the elements are déraffinés,
·
“NOTHING”: all the elements are preserved; the mesh is the same one at the exit as with
the input.
4.1.3 Operand
MAILLAGE_N
MAILLAGE_N = man
Mesh of the type [mesh] to adapt. Attention, the adaptation can relate only to
simplexes: segments, mesh-points, triangles, quadrangles or tetrahedrons, in degree 1 or 2. If one
provides a comprising mesh of other elements, two cases of figure are possible: that is to say a stop
in error, that is to say an adaptation on the area in simplex and a restitution with identical of the remainder of
mesh. The choice between these two operating modes is made by the key word
NON_SIMPLEXE.
4.1.4 Operand
MAILLAGE_NP1
MAILLAGE_NP1
= Co
(manp1)
The name of the concept of the type [mesh] which will contain the mesh resulting from the adaptation. This name
must respect the usual stresses of the names of concept (8 characters to the maximum) and
to be never used.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
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Author (S):
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Key
:
U7.03.01-D1
Page:
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4.1.5 Operand
RESULTAT_N
RESULTAT_N = resun
This operand makes it possible to indicate the concept of the type [result] which contains the indicator of error
to use for free adaptation.
4.1.6 Operand
INDICATOR
INDICATOR = indic
One specifies here which is the indicator of error which is used for the adaptation.
Caution:
The field must be present in the result; if it misses, it is not calculated of office.
The user has the choice of the indicator: maybe of the fields already defined out of standard in
Aster (cf [U4.81.02] and [U4.81.03], is a personalized field. With him to choose what is
relevant for its calculation.
4.1.7 Operand
CHAM_GD
CHAM_GD = cham_gd_i
This operand makes it possible to indicate the concept of the type [cham_gd] which contains the indicator of error with
to use for free adaptation.
4.1.8 Operand
NOM_CMP_INDICA
NOM_CMP_INDICA = cmp
Name of the component of the indicating field which must be used to control the adaptation of
mesh.
4.1.9 Selection of the temporal parameter
If the structure of result contains the field of indicator of error only for one sequence number,
nothing is to be specified. In fact the values of the field to this sequence number will be used.
If not, it is necessary to specify about which number it is. That is done by the designation of a sequence number or
of a value of moment. To refer to the document [U4.71.00] for the details on these key words.
4.1.10 CRIT_RAFF_xxxx operand
In the case of free adaptation implying of the refinement of mesh, it is necessary to define a high criterion of
the error. All the elements for which the indicator of error is higher than this criterion will be refined.
It is important to look at a posteriori the pace of the frequency of errors. That is possible thanks to
impressions carried out by LOBSTER in the file
mess
. One will find there in particular a table
presenting this distribution in the form of histogram; to see chapter 5 for an example with accompanying notes.
For the choice of the criterion, three alternatives are possible:
4.1.10.1 Operand CRIT_RAFF_PE
/CRIT_RAFF_PE = crp
The criterion is defined by a proportion of elements to refine. It is a real number included/understood
between 0 and 1. The process is as follows:
·
calculation of the number of elements N corresponding to the proportion defined by crp is
N = crp X numbers total elements
·
refinement of N elements with the strongest error.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
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4.1.10.2 Operand CRIT_RAFF_ABS
/CRIT_RAFF_ABS = CRA
The criterion is defined by an absolute value of the error. All elements with an error
higher than this value will be refined.
4.1.10.3 Operand CRIT_RAFF_REL
/CRIT_RAFF_REL = crr
The criterion is defined by a relative value of the error. It is a number ranging between 0 and 1.
The process is as follows:
·
calculation of the minimal and maximum values of the indicator of error,
·
calculation of the value corresponding to the proportion of error: v = vmin + crr (vmax
vmin),
·
refinement of all the elements whose error is higher than this value.
4.1.11 CRIT_DERA_xxxx operand
In the case of free adaptation implying of déraffinement, it is necessary to define a low criterion of error. All
the elements whose error is lower than this criterion will be déraffinés. Three alternatives are possible.
4.1.11.1 Operand CRIT_DERA_PE
/CRIT_DERA_PE = cdp
The criterion is defined by a proportion of elements to refine. It is a number ranging between 0
and 1. The process is as follows:
·
calculation of the number of elements N corresponding to the proportion defined by cdp is N =
cdp X numbers total elements
·
déraffinement N elements with the weakest error.
4.1.11.2 Operand CRIT_DERA_ABS
/CRIT_DERA_ABS = half-value layer
The criterion is defined by an absolute value of the error. All elements with an error
lower than this value will be déraffinés.
4.1.11.3 Operand CRIT_DERA_REL
/CRIT_DERA_REL = cdr
The criterion is defined by a relative value of the error. It is a number ranging between 0 and 1.
The process is as follows:
·
calculation of the minimal and maximum values of the indicator of error,
·
calculation of the error value V corresponding to the proportion of cdr error such as:
v = vmin + cdr (vmax vmin),
·
déraffinement of all the elements whose error is lower than this value.
4.1.12 Operand NIVE_MAX
NIVE_MAX = nivmax
It is the maximum level of refinement of the mesh. In other words an element of the initial mesh
could not be divided more nivmax time as a whole of the process.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
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Key
:
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Page:
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4.1.13 Operand NIVE_MIN
NIVE_MIN = nivmin
It is the minimal level of déraffinement mesh. I.e. only elements resulting
of at least nivmin cuttings of mesh can be déraffinés.
4.2 Word
key
MAILLAGE_FRONTIERE
MAILLAGE_FRONTIERE = maf
In dimension 2, the choice of this option makes it possible the process of adjustment to follow the curvature
edges of the mesh. One provides here a Code_Aster concept of the mesh type which contains one
fine mesh of the edges of the geometry. This mesh is thus made a priori only of segments.
Their lengths are much lower than those of the segments of edge of the mesh to adopt. If it
process of adjustment is brought to cut a segment of edge, the new node will be placed on
mesh of the border. Thus the angles will progressively be softened adaptations.
The identification of the various edges is done by the groups according to the following rule: the segments which
form an edge are gathered in a group which bears the same name in the mesh of
calculation and in the mesh of the border.
The case-tests will be looked at
ZZZZ121d
and
ZZZZ175a
for examples of follow-up of border.
4.2.1 Operand
GROUP_MA
GROUP_MA
= l_grma
If this option misses, the follow-up of the border is done for all the groups defined in
mesh of the border. If one wishes to restrict this follow-up with part of the border, one gives
here the list of the groups of segments which define this part of border.
4.3 Word
key
MAJ_CHAM
MAJ_CHAM = _F
(
This key word is to be employed once as many as one has fields to update old mesh
towards the adapted mesh.
4.3.1 Operand
RESULT
RESULT
= resu
Name of the concept [result] containing the field to be updated.
4.3.2 Operand
NOM_CHAMP
NOM_CHAMP
=
nomsymb [K16]
Reference symbol of the field which one wishes to express on the new mesh.
4.3.3 Operand
CHAM_GD
CHAM_GD
=
cham_gd
Name of the concept [cham_gd] containing the field to be updated.
4.3.4 Selection of the temporal parameter
The selection of the sequence number associated with the field to be interpolated is done by the designation of a number
of command or a value of moment. To refer to the document [U4.71.00] for the details on these key words.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
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4.3.5 Operand
CHAM_MAJ
CHAM_MAJ
= Co
(chpmaj)
[K8]
Name of the concept which will contain the field expressed on the new mesh. This concept does not have
not to exist. It will be automatically created.
4.3.6 Operand
TYPE_CHAM
TYPE_CHAM
=/“NOEU_DEPL_R”
/
“NOEU_TEMP_R”
/
etc
…
One indicates the type of the concept here to be updated on the new mesh. The name of this type is
built with the usual logic of Code_Aster. The first 4 characters are “NOEU”,
“ELEM”, “ELNO” or “ELGA”. One finds “_ then”. The following sequence defines the type of
field: “TEMP”, “DEPL”, etc the name ends in “_R” for a real field.
Example: “NOEU_TEMP_R”, “NOEU_DEPL_R”, etc
Caution:
There is no consistency check between the type requested and the true type of
field to be interpolated.
4.4 Operand
NUMBERS
Note:
One will consult the document [U7.03.02] describing the control
MACR_INFO_MAIL
for
comments on the restitutions of the operands
QUALITY
,
INTERPENETRATION
,
NUMBERS
,
CONNEXITY
and
CUT
.
NUMBERS
=
/
“YES”
[DEFECT]
/
“NOT”
If the choice is “NOT”, nothing occurs.
If the choice is “YES”, an assessment of the numbers of nodes and elements are printed on the file of
messages.
4.5 Operand
QUALITY
QUALITY
=
/“YES”
/
“NOT”
[DEFECT]
If the choice is “NOT”, nothing occurs.
If the choice is “YES”, an assessment of the quality of the elements is printed on the file of message.
The quality of a triangle is defined as being the relationship between the length on the largest side and
the radius of the inscribed circle. The quality of a quadrangle is defined like the quotient of the product of
the biggest length and of the averages on the sides and the diagonals by smallest of
surfaces of the triangles intern with the quadrangles. In the same way, the quality of a tetrahedron is defined
as being the relationship between the length on the largest side and the radius of the registered sphere. These
reports/ratios are standardized to be worth 1 in the case of an equilateral triangle, of a square, or one
equilateral tetrahedron. For any nonequilateral element, quality is higher than 1. See
reference [bib1] for detailed explanations.
The result is presented in the form of tables, with the extreme values.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
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Key
:
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Page:
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4.6 Operand
INTERPENETRATION
INTERPENETRATION
=/“YES”
/
“NOT”
[DEFECT]
If the choice is “NOT”, nothing occurs.
If the choice is “YES”, it is checked that the mesh is correct from the point of view of the recovery:
no triangle is with horse on another triangle, no quadrangle is not with horse on another
quadrangle, no tetrahedron enters another tetrahedron.
4.7 Operand
CUT
CUT
=
/
“YES”
/
“NOT”
[DEFECT]
If the choice is “NOT”, nothing occurs.
If the choice is “YES”, an assessment of the sizes of the under-fields is printed on the file of
messages. A under-field is defined like a whole of of the same meshs dimension and
belonging to the same groups.
4.8 Operand
CONNEXITY
CONNEXITY
=
/
“YES”
/
“NOT”
[DEFECT]
If the choice is “NOT”, nothing occurs.
If the choice is “YES”, an assessment of the connexities is printed on the file of messages. One specifies
then if the segments, the elements 2D (joined together triangles and quadrangles) or the tetrahedrons are
of only one holding or divided into several blocks.
4.9 Operand
LANGUAGE
LANGUAGE
=
/
“FRENCH” [DEFECT]
“FRENCH”
“ENGLISH”
“ENGLISH”
This operand specifies the language in which the messages resulting from LOBSTER are printed.
4.10 Operand
VERSION_HOMARD
VERSION_HOMARD
=
“V7_7”
[DEFECT]
“V7_N'
“V7_N_PERSO”
This operand makes it possible to select the LOBSTER version which is used for the adaptation.
By defect, LOBSTER 7.7 is launched. It is the version of reference. Choice “V7_N' activates
version 7.n of LOBSTER which is the version of development. Active choice “V7_N_PERSO”
a version of development specific to the user. This option in fact is reserved for the team of
development of LOBSTER to develop new functionalities.
4.11 Operand
INFORMATION
INFORMATION
=
/1
/2
If INFORMATION is worth 2, the entirety of the LOBSTER exit is included in the file of message.
If not, nothing in particular takes place.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
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Page:
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4.12 Operand
NON_SIMPLEXE
NON_SIMPLEXE
=/0
/1
/
2
[DEFECT]
In its current version, LOBSTER can read all the types of elements but does not make carry
the adaptation that on some: mesh-points, segments, triangles, quadrangles and tetrahedrons.
By retaining option 0, the transmission of a mesh containing another thing that simplexes
a stop in error will involve.
By choosing option 1, one will be able to transmit a mesh comprising any type
of element. The adaptation will relate only to the area in simplexes or quadrangles. So consequently
from propagation of refinement, an area in hexahedron or pentahedron came to be touched, there is
a stop in error. If not, when refinement is limited to the area in simplexes or in
quadrangles, the other elements are restored without change.
With option 2, one authorizes refinement only on all the elements which LOBSTER can treat:
mesh-points, segments, triangles, quadrangles and tetrahedrons. The presence of hexahedrons or of
pentahedrons will cause a stop in error. It is the default option.
5 Example
One will look with profit the command files associated with the ZZZZ121a case-tests, B, C, D. They
the processes of adjustment of mesh in the form of a loop in Python language express.
Here an example of parameter setting of the macro-control.
MACR_ADAP_MAIL (
ADAPTATION =
_F
(
FREE
=
“RAFF_DERA”,
MAILLAGE_N
=
mun,
MAILLAGE_NP1
=
CO
(“mdeux”),
RESULTAT_N
=
remeun,
INDICATOR
=
“ERRE_ELGA_NORE”,
NOM_CMP_INDICA
=
“ERREST”
NUME_ORDRE
=
3,
CRIT_RAFF_PE
=
0.01,
CRIT_DERA_PE
=
0.25,
NIVE_MAX
=
5
),
MAJ_CHAM
=
_F
(
RESULT
=
rethun,
NOM_CHAM
=
“TEMP”,
TYPE_CHAM
=
“NOEU_TEMP_R”,
INST
=
12.5,
CHAM_MAJ
=
CO
(“tempdeux”)
),
QUALITY
=
“YES”,
INTERPENETRATION
=
“NOT”
)
This sequence will adapt the mesh contained in the concept mun and will restore a concept mesh
of mdeux name. The adaptation is done by refinement and déraffinement free, according to the indicator of error
contents in field ERRE_ELGA_NORE of the remeun result, to the 3
ème
moment; the component used
is ERREST. The elements will be classified according to their level of error decreasing. The first
% will be refined; the 25% the last will be candidates with déraffinement. No element of the final mesh
will not have to be resulting of more than 5 refinements.
The field TEMP of the rethun result at the moment 12,5 is expressed on the mesh mun. It will be expressed
on the mdeux mesh in the shape of the field of temperature to the tempdeux nodes.
A summary of the quality of the elements of the new mesh is produced. One does not control
interpenetration of the elements.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
12/14
Instruction manual
U7.0- booklet: Data exchanges
HT-62/06/004/A
Here an example of the table presenting the distribution of the indicator of error on the mesh.
**********************************************************
* Indicators of error on the mesh of calculation *
* Error on the 956 triangles *
**********************************************************
* Minimum: 40.577 Maximum: 71888. *
**********************************************************
**********************************************************
* Function of distribution *
**
* Values * a Number of elements *
* Minicomputer < < Maximum * by class * office plurality *
** 10 ** 4 * in %. numbers * in %. numbers *
**********************************************************
* 0.00 < 0.36 * 89.33. 854 * 89.33. 854 *
* 0.36 < 0.72 * 9.62. 92 * 98.95. 946 *
* 0.72 < 1.08 * 0.21. 2 * 99.16. 948 *
* 1.08 < 1.44 * 0.10. 1 * 99.27. 949 *
* 1.44 < 1.80 * 0.31. 3 * 99.58. 952 *
* 1.80 < 2.16 * 0.10. 1 * 99.69. 953 *
* 2.16 < 2.52 * 0.00. 0 * 99.69. 953 *
* 2.52 < 2.88 * 0.00. 0 * 99.69. 953 *
* 2.88 < 3.24 * 0.00. 0 * 99.69. 953 *
* 3.24 < 3.60 * 0.00. 0 * 99.69. 953 *
* 3.60 < 3.96 * 0.00. 0 * 99.69. 953 *
* 3.96 < 4.32 * 0.00. 0 * 99.69. 953 *
* 4.32 < 4.68 * 0.10. 1 * 99.79. 954 *
* 4.68 < 5.04 * 0.00. 0 * 99.79. 954 *
* 5.04 < 5.40 * 0.00. 0 * 99.79. 954 *
* 5.40 < 5.76 * 0.00. 0 * 99.79. 954 *
* 5.76 < 6.12 * 0.00. 0 * 99.79. 954 *
* 6.12 < 6.48 * 0.00. 0 * 99.79. 954 *
* 6.48 < 6.84 * 0.10. 1 * 99.90. 955 *
* 6.84 < 7.20 * 0.10. 1 * 100.00. 956 *
* 7.20 < inf. * 0.00. 0 * 100.00. 956 *
**********************************************************
0
10
20
30
40
50
60
70
80
90
100
0,00 < 0,36
0,36
< 0,72
0,72 < 1,08
1,08
< 1,44
1,44 < 1,80
1,80
< 2,16
2,16 < 2,52
2,52
< 2,88
2,88 < 3,24
3,24
< 3,60
3,60
< 3,96
3,96 < 4,32
4,32
< 4,68
4,68 < 5,04
5,04
< 5,40
5,40 < 5,76
5,76
< 6,12
6,12 < 6,48
6,48
< 6,84
6,84 < 7,20
Range of error
Percentage of élém
ents
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
13/14
Instruction manual
U7.0- booklet: Data exchanges
HT-62/06/004/A
The diagnosis on the distribution of the indicator of error on the mesh points out initially the values
extremes met in calculation in progress. Here the minimum is 40,577 and the maximum of 71888.
Then one presents the distribution by equidistant section starting from the optimum value, 0. It is seen that
854 triangles have an error lower than 0,36 * 10
4
, that is to say 89,33% of the total number of triangles.
92 triangles have an error ranging between 0,36 * 10
4
and 0,72 * 10
4
, that is to say 9,62% of the total number of
triangles. In cumulated, one thus notes that 946 (=854+92) triangles have an error lower than
0,72 * 10
4
, that is to say 98,95% of the total. And so on. For example, 99,58% of the elements have an error
lower than 1,80 * 10
4
.
On the preceding figure, one can see the representation in the form of histogram of the percentages
elements in each range of error concerned. As it could also
to note in the preceding table, one notes that very few elements concentrate a strong error.
By visualizing a representation of the cumulated percentage of elements in a range of error given,
one with the following figure.
82
84
86
88
90
92
94
96
98
100
102
0,00 < 0,36
0,36
< 0,72
0,72 < 1,08
1,08
< 1,44
1,44 < 1,80
1,80
< 2,16
2,16 < 2,52
2,52
< 2,88
2,88 < 3,24
3,24
< 3,60
3,60
< 3,96
3,96 < 4,32
4,32
< 4,68
4,68 < 5,04
5,04
< 5,40
5,40 < 5,76
5,76
< 6,12
6,12 < 6,48
6,48
< 6,84
6,84 < 7,20
Range of error
Cum percentage
U
breadth of élém
ents
From this frequency of errors, one can deduce two consequences on the strategies from refinement.
If one asks for a refinement on a relative criterion of the error, key word
CRIT_RAFF_REL
, that returns to
to select the elements the elements which are on the right vertical line passing by it
criterion. For example if one asks
CRIT_RAFF_REL = 0.85
, all the elements will be selected
whose L `error is higher than 0,85 * 71888, that is to say 61105. It is noted that that corresponds to very little
elements: 2 only exceed this value, i.e. 0,2% of the total.
If one asks for a refinement on a percentage of elements, key word
CRIT_RAFF_PE
, that returns to
to select the elements the elements which are above the horizontal line passing by
this criterion. For example if one asks
CRIT_RAFF_PE = 0.85
, the 15% will be selected
the worst elements, is 143 elements. Among these, “the least worse” has an error lower than
3600, is 20 times smaller than the maximum.
The consequence of these remarks is that it is advisable to make a first analysis of the distribution of
the error before choosing the type and the values of the criteria of refinement. It is indeed useless, even
expensive in term of increase in the size of mesh, to refine in areas where the error is not
not very strong. The adaptation will be all the more powerful as one will have known to reduce the elements to strong
error until obtaining a balance of the frequency of errors in the mesh.
Code_Aster
®
Version
8.2
Titrate:
Macro-control
MACR_ADAP_MAIL
Date:
31/01/06
Author (S):
G. NICOLAS
Key
:
U7.03.01-D1
Page:
14/14
Instruction manual
U7.0- booklet: Data exchanges
HT-62/06/004/A
6 Bibliography
[1]
G. NICOLAS: “Software LOBSTER - Volume 1 - general Presentation”, report/ratio EDF
HI-23/04/005, February 2005.
[2]
G. NICOLAS: “Software LOBSTER - Volume 2 Algorithmes of refinement and déraffinement
mesh ", report/ratio EDF HI-23/04/006, February 2005.
[3]
G. NICOLAS: “Software LOBSTER - Volume 3 Interfaces with the computer codes”, report/ratio
EDF HI-23/04/007, February 2005.
[4]
G. NICOLAS: “Software LOBSTER - Volume 4 Structures of data”, report/ratio EDF
HI-23/04/008, February 2005.