Code_Aster ®
Version
8.2
Titrate:
Operator AFFE_MATERIAU


Date:
31/01/06
Author (S):
J. Key PELLET
:
U4.43.03-I1 Page
: 1/6

Organization (S): EDF-R & D/AMA

Handbook of Utilization
U4.4- booklet: Modeling
Document: U4.43.03

Operator AFFE_MATERIAU

1 Goal

To assign materials to geometrical zones of a grid.

Product a structure of data of the cham_mater. type.
Handbook of Utilization
U4.4- booklet: Modeling
HT-62/06/004/A

Code_Aster ®
Version
8.2
Titrate:
Operator AFFE_MATERIAU


Date:
31/01/06
Author (S):
J. Key PELLET
:
U4.43.03-I1 Page
: 2/6

2 Syntax

chm [cham_mater] = AFFE_MATERIAU




(
MAILLAGE = my
,
/
[grid]
/
[skeleton]





MODELE = Mo, [model]





# assignment of the name of material and the temperature of reference:





AFFE
=
(_F (










/TOUT =
“OUI”,
/
MAILLE


= lma
,
[l_maille]
/
GROUP_MA
= lgma

,
[l_gr_maille]










MATER
=/chechmate
,
[to subdue]







/
l_mat,
[l_mater]











TEMP_REF
=/0.
, [DEFAUT]
/
tref,
[R]










SECH_REF = sref,


[R]
),),





# assignment of the variables of commands:





AFFE_VARC
= (_F (

/TOUT =
“YES”, [DEFECT]
/
|
MAILLE


= lma
, [l_maille]
|
GROUP_MA
= lgma,
[l_gr_maille]










NOM_VARC
=/“IRRA”,







/
“CORR”,







/
“NEUT1”,







/
“NEUT2”,










/
CHAMP_GD = chvarc
[field]










/
EVOL
= evovarc [evol_sdaster]











NOM_CHAM = nosymb, [TXM]
















VALE_REF = vref, [R]
),),




)

Handbook of Utilization
U4.4- booklet: Modeling
HT-62/06/004/A

Code_Aster ®
Version
8.2
Titrate:
Operator AFFE_MATERIAU


Date:
31/01/06
Author (S):
J. Key PELLET
:
U4.43.03-I1 Page
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3 General information

This command is used to affect the material characteristics on the finite elements of the model
(even if in fact the meshs of the grid are really affected). These characteristics
material are defined by the materials which one affects on the meshs (key word MATER). Each
material contains a certain number of parameters (Young modulus, density,…). These
parameters can be related to certain variables. We will call these variables of
“variable of command”.

Currently, the variables of command used (in mechanics) are the temperature, the hydration,
drying, phases metallurgical, irradiation, corrosion,… Mais only affected variables
via command AFFE_MATERIAU for the moment the irradiation (IRRA) and corrosion (CORR) are.

4 Operands

4.1
MAILLAGE

MAILLAGE = my,

Name of the grid (or the skeleton) which one wants to affect by material characteristics.

Note:

The operation of assignment is the same one for the meshs of a skeleton as for the meshs of one
grid. In the continuation of the document, one will always say grid to simplify.
When one affects materials on the meshs of a skeleton, it is that one wants to calculate
constraints (for example) on the meshs of postprocessing (coarser).

4.2 Place
of assignment

AFFE

Key word factor which makes it possible to affect various materials on “pieces” of the grid.


/ALL = “YES”,

This key word makes it possible to affect on all the meshs of the grid.


/GROUP_MA = lgma,

This key word makes it possible to affect on a list of groups of meshs of the grid.

/
MAILLE
=
lma,

This key word makes it possible to affect on a list of meshs of the grid.

With each group of meshs, (key word GROUP_MA) or each list of meshs (key word MAILLE),
or with all the grid (key word TOUT) is affected a material chechmate, which is a concept
product by one of operators DEFI_MATERIAU [U4.43.01] or DEFI_COQU_MULT [U4.42.03].

Let us recall that command DEFI_MATERIAU [U4.43.01] makes it possible to define the parameters of
relations of behavior to be used for a mechanical, thermal, acoustic analysis.
order DEFI_COQU_MULT [U4.42.03] allows to define a homogenized material
representative of a laminated material multi-layer.

If a mesh appears explicitly (or implicitly) in several occurrences of the key word
factor AFFE, the rule of overload is applied: it is the last assignment which precedes
[U2.01.08].

Handbook of Utilization
U4.4- booklet: Modeling
HT-62/06/004/A

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4.3
Quantities to be affected

4.3.1 Notice concerning calculations of breaking process
In general, the material characteristics must be known finite elements modelling
“matter”: “voluminal” elements (or of structure). The finite elements of “skin” are there for
to apply boundary conditions and do not have to know the material properties of the matter
subjacent. An exception exists for the calculation of option CALC_K_G of the operators
. For these calculations, the finite elements modelling the lips of the fissure must be
affected by same material as the “voluminal” elements subjacent.

4.3.2 Operand
MATER

MATER = chechmate,

Name of the material which one wants to affect.

In the general case, each mesh is affected only by one material. Sometimes, it is necessary
to indicate a material list when the nonlinear mechanical behavior is obtained by
order DEFI_COMPOR [U4.43.06].

4.3.3 Operand
TEMP_REF

TEMP_REF = Tref,

The temperature of Tref reference introduced behind key word TEMP_REF is the temperature for
which it does not have there thermal deformation (cf [R4.08.01]).

If the thermal dilation coefficient (of which the value is introduced into the command
HT
DEFI_MATERIAU [U4.43.01]) does not depend on the temperature:
(T) = (T - ref.
T).

If the thermal dilation coefficient depends on the temperature the mathematical expression
allowing the calculation of the thermal deformation differs according to the specification from
thermal dilation coefficient in command DEFI_MATERIAU:

·
the values of the thermal dilation coefficient (introduced into DEFI_MATERIAU) have
summer determined by tests of dilatometry carried out at the Tref temperature.
In this case, key word TEMP_DEF_ALPHA should not be specified in the command
DEFI_MATERIAU and the thermal deformation are calculated by the expression:

HT (T) = (T) (
HT
T - ref.
T) and (ref.
T) = 0

where (T) is well informed under key word ALPHA (or ALPHA_ *) in DEFI_MATERIAU.

·
the values of the thermal dilation coefficient are determined by tests of
dilatometry which took place at a Tdef temperature different from the temperature from
Tref reference.
It is then necessary to carry out a change of reference mark in the calculation of the deformation
thermics [R4.08.01].

HT (T) = HT (T) - HT
m
m (ref.
T)

where thm is the thermal deformation measured (definite compared to the temperature
Tdef),

HT is the thermal deformation calculated (definite compared to the temperature
Tref).
Handbook of Utilization
U4.4- booklet: Modeling
HT-62/06/004/A

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Titrate:
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The Tdef temperature is indicated under key word TEMP_DEF_ALPHA in
DEFI_MATERIAU, and values of the dilation coefficient (definite compared to
Tdef temperature) are indicated under key word ALPHA or (ALPHA_ *) in
DEFI_MATERIAU.

4.3.4 Operand
SECH_REF

SECH_REF: c0 [R]

c0 represents the water content initial of the concrete. The user must provide this number when it does one
mechanical calculation (MECA_STATIQUE or STAT_NON_LINE) with a loading of the type
SECH_CALCULEE.

c0 must be given in the same units as the “drying” of SECH_CALCULEE (for example in
L/m3). This unit must be coherent with parameter DEFI_MATERIAU/ELAS_FO/K_DESSIC.

With this water content initial, the withdrawal of desiccation is null since:
EPS_rd = K_DESSIC (C0-C).

4.4 Word
key
AFFE_VARC

This key word factor makes it possible to affect fields of variables of command on the meshs of
grid. An occurrence of the key word is used to affect a variable of command. For the moment, both
variables of command usable in this command (IRRA and CORR) have each one only one
component (IRRA and COOR) but it is envisaged for example that a defomation (6 components EPXX,
EPYY,…) can be a variable of command.

4.4.1 Operand
NOM_VARC

NOM_VARC = nomvarc,

Name of the variable of command which one wants to affect (IRRA or CORR).

4.4.2 Operands
TOUT=' OUI', GROUP_MA=lgma, MAILLE=lmail
These key words make it possible to indicate the zone to be affected.

4.4.3 Operand
CHAMP_GD=chvarc

This key word makes it possible to associate the variable of command nomvarc the field chvarc. This field is
a field of realities (not of functions). It is thus independent of time and will be used throughout
transitory calculations.
If the values of the variable of command are dependant on time, it is necessary to use key word EVOL
(see below).
In the field chvarc, the program will seek a of the same component name than nomvarc.

4.4.4 Operands
EVOL=evovarc and NOM_CHAM=nomsym

These key words make it possible to associate the variable of command nomvarc the transient evovarc.
key word NOM_CHAM makes it possible to indicate the reference symbol of the fields of SD_résultat to be used.
By defect, the code chooses NOM_CHAM=' IRRA' for NOM_VARC=' IRRA' and NOM_CHAM=' CORR' for
NOM_VARC=' CORR'. The fields are fields of realities (not functions). In these fields, it
program will seek a of the same component name than nomvarc.

4.4.5 Operand
VALE_REF=vref

This key word makes it possible to define a value of “reference” for the variable of command nomvarc. By
example, when drying is treated like a variable of command in the key word
AFFE_VARC, key word VALE_REF will replace key word current SECH_RÉF. Les 2 variables current
(IRRA and CORR) do not have a value of reference.
Handbook of Utilization
U4.4- booklet: Modeling
HT-62/06/004/A

Code_Aster ®
Version
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Titrate:
Operator AFFE_MATERIAU


Date:
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Author (S):
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:
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5 Examples

Example 1

chmat = AFFE_MATERIAU (MAILLAGE = my, AFFE = (



_F (TOUT = “OUI”, MATER = steel),
_F (MAILLE= (“ma1”, “ma2”, “ma3”), MATER=alu,
TEMP_REF=20.),),







)

On the whole of the grid (except the meshs: ma1, ma2, ma3) are affected the material of name steel
with the temperature of reference per defect: 0.

On the meshs ma1, ma2, ma3 are affected the material aluminum with the temperature of reference 20.

Example 2

Assignment on all the grid of the material MAT whose certain parameters are related to
irradiation. The temporal evolution of the irradiation is given via the SD result EVOL = FLUENC.

CHMAT = AFFE_MATERIAU (GRID = MA,
AFFE =_F (TOUT=' OUI', MATER = CHECHMATE,),
AFFE_VARC=_F (NOM_VARC=' IRRA', EVOL =FLUENC,),
)

Example 3

Use of the variable of command “NEUT1” to simulate a dependence of the coefficients
hardware according to the Young modulus.
In this example (resulting from the case test ssnv130c), one wants to illustrate the possibility of using a field of
Young modulus whom one supposes known (CHYOUNG). For example, this field is read in a file
(LIRE_CHAMP) or it is the result of a calculation. One then will define a material for which
Young modulus (key word E) is the function “identity” of variable “NEUT1” and the field is affected
CHYOUNG like variable of command “NEUT1”.

CHYOUNG=…
NU_F=DEFI_CONSTANTE (VALE=0.3)
E_F = DEFI_FONCTION (NOM_PARA=' NEUT1', VALE= (- 1.E-9, - 1.E-9, 1.E+9,1.E+9));
MA=DEFI_MATERIAU (ELAS_FO=_F (E=E_F, NU=NU_F,),);

CM=AFFE_MATERIAU (MAILLAGE=M,
AFFE=_F (TOUT= “YES”, MATER= MA),
AFFE_VARC=_F (NOM_VARC=' NEUT1', CHAMP_GD=CHYOUNG),
)

Handbook of Utilization
U4.4- booklet: Modeling
HT-62/06/004/A

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