Code_Aster
®
Version
7.4
Titrate:
Operator
POST_K_BETA
Date:
08/02/05
Author (S):
A. DAHL,
S. BUGAT, R. FERNANDES
Key
:
U4.82.07-B
Page
:
1/6
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
HT-66/05/004/A
Organization (S):
EDF-R & D/MMC, AMA
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
Document: U4.82.07
Operator
POST_K_BETA
1 Goal
Analyze harmfulness of defect by the method K-beta.
This method aims to evaluate the factors of margins with respect to the priming of the tear
coating (in first point of the defect) and with respect to the brittle fracture of the base metal or of
welded gasket (in second point of the defect).
POST_K_BETA calculates the stress intensity factors to the two points of the defect, using
stresses with the nodes resulting from the mechanical resolution [R7.02.10].
This method calculates the stress intensity factors on models in which the fissure
is not represented. It uses the stresses with the nodes along a segment of support of the defect
postulated. The stress intensity factors obtained are those of a defect under coating of
elliptic profile, under the assumption of an elastic behavior of materials.
“Correction
”, specific to the defects under coating stuck to the interface, allows to hold account
plasticization with the two points of the fissure side coating (point A) and side base metal
(point B).
Product a concept of the type counts.
Code_Aster
®
Version
7.4
Titrate:
Operator
POST_K_BETA
Date:
08/02/05
Author (S):
A. DAHL,
S. BUGAT, R. FERNANDES
Key
:
U4.82.07-B
Page
:
2/6
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
HT-66/05/004/A
2 Syntax
tk [table] = POST_K_BETA
(
MESH
=
my,
[mesh]
MATER_REV = chechmate, [material]
EPAIS_REV
=
epais_rev,
[R]
FISSURE =_F
(
|
SHIFT =
/- 2.10
- 4
,
[DEFECT]
/shift, [R]
|
DEPTH =
depth, [R]
|
LENGTH =
length, [R]
|
ORIENTATION =
/
'
CIRC
',
/
'
LONGI
',
),
K1D = (_F (
|
TABL_MECA_REV =
table_rev, [table]
|
TABL_MECA_MDB =
table_mdb, [table]
|
TABL_THER =
table_ther, [table]
|
ENTITLE =
heading, [K]
),),
TITRATE
=
titrate
,
[l_K]
)
Code_Aster
®
Version
7.4
Titrate:
Operator
POST_K_BETA
Date:
08/02/05
Author (S):
A. DAHL,
S. BUGAT, R. FERNANDES
Key
:
U4.82.07-B
Page
:
3/6
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
HT-66/05/004/A
3 Operands
Axisymmetric schematization of a section of tank with presence of a defect under-coating.
Depth
defect
defect
Coating
Base metal
With
B
Center
the tank
laughed
erev
emdb
Shift
3.1 Operand
MESH
Concept of the type
mesh
.
3.2 Operand
MATER_REV
Name of the concept of the type
material
defining material constituting the coating. Necessary for
to recover the yield stresses, for the plastic correction of the stress intensity factors.
3.3 Operand
EPAIS_REV
Thickness of the coating. Necessary for the correction of the stress intensity factors by
factors of edges and for the plastic correction.
3.4 Word
key
FISSURE
Key word factor for the geometrical characterization of the defect. It can be used only only once.
3.4.1 Operand
SHIFT
Shift of the fissure in the coating starting from the interface coating/base metal. To note
that the shift is necessarily negative. By defect, shift = 2.10
4
.
3.4.2 Operand
DEPTH
Radial dimension of the defect.
3.4.3 Operand
LENGTH
The second dimension of the defect (axial or orthoradiale according to the orientation of the defect).
3.4.4 Operand
ORIENTATION
Characterization of the orientation of the defect: “CIRC” for a circumferential defect,
“LONGI” for a longitudinal defect.
Code_Aster
®
Version
7.4
Titrate:
Operator
POST_K_BETA
Date:
08/02/05
Author (S):
A. DAHL,
S. BUGAT, R. FERNANDES
Key
:
U4.82.07-B
Page
:
4/6
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
HT-66/05/004/A
3.5 Word
key
K1D
Key word factor for the characterization of the thermomechanical transient. The repetition of this key word is
possible.
3.5.1 Operands
TABL_MECA_REV and TABL_MECA_MDB
Tables providing the transient of the stresses undergone by the tank during the history of
loading, respectively side coating (of point A of the defect to the interface) and side metal of
base (interface with the point B of the defect).
3.5.2 Operand
TABL_THER
Count providing the thermal transient in the tank during the history of the loading of
point A with the point B.
3.5.3 Operand
ENTITLE
Heading to specify the group of nodes considered.
3.6 Operand
TITRATE
Titrate attached to the concept produced by this operand [U4.03.01].
4 Example
Examples of use of control POST_K_BETA are provided in the case test EPICU01.
Before the use of control POST_K_BETA, it is necessary to record the stresses and them
temperatures along the defect.
In the example below, the paths chem1, chem2 and chem3 on which recordings of
stress and of temperature will be carried out are first of all defined.
Definition of chem1 which goes from the point of the defect side coating until the interface.
CHEM1=INTE_MAIL_2D (MESH = MALL,
GROUP_MA
=
“R”,
INFORMATION
=
2,
PRECISION
=
1.0E-6,
DEFI_SEGMENT
=
_F (
ORIGIN
=
(DEBFIS,
0.0),
GROUP_NO_EXTR
=
“Pi”,
)
)
Definition of chem2 which goes from the interface to the point of the defect side base metal.
CHEM2=INTE_MAIL_2D (MESH = MALL,
GROUP_MA
=
“Me,
PRECISION
=
1.0E-6,
INFORMATION
=
2,
DEFI_SEGMENT
=
_F (
GROUP_NO_ORIG
=
“Pi”,
END
=
(EXTRABS,
0.0),
)
)
Code_Aster
®
Version
7.4
Titrate:
Operator
POST_K_BETA
Date:
08/02/05
Author (S):
A. DAHL,
S. BUGAT, R. FERNANDES
Key
:
U4.82.07-B
Page
:
5/6
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
HT-66/05/004/A
Definition of chem3 which goes from the point of the defect side coating to that side base metal.
CHEM3=INTE_MAIL_2D (MESH = MALL,
PRECISION
=
1.0E-6,
INFORMATION
=
2,
DEFI_SEGMENT
=
_F (
ORIGIN
=
(DEBFIS,
0.0),
END
=
(EXTRABS,
0.0),
)
)
Recording of the stresses on chem1: the stresses are recorded on the part of the defect located in
coating.
S1_G=POST_RELEVE_T (ACTION=_F
(PATH
=
CHEM1,
ENTITLE
=
“GLOBAL1”,
RESULT
=
SIG,
TOUT_CMP
=
“YES”,
NOM_CHAM
=
“SIGM_ELNO_DEPL”,
LIST_INST
=
LINST_ME,
OPERATION
=
“EXTRACTION”,
)
)
Recording of the stresses on chem2: the stresses are recorded on the part of the defect located in
base metal.
S2_G=POST_RELEVE_T (ACTION=_F
(PATH
=
CHEM2,
ENTITLE
=
“GLOBAL2”,
RESULT
=
SIG,
TOUT_CMP
=
“YES”,
NOM_CHAM
=
“SIGM_ELNO_DEPL”,
LIST_INST
=
LINST_ME,
OPERATION
=
“EXTRACTION”,
)
)
Recording of the temperatures on chem3: the temperature is recorded along the defect.
TEMP_G=POST_RELEVE_T (ACTION=_F
(PATH
=
CHEM3,
ENTITLE
=
“GLOBAL3”,
RESULT
=
TEMP,
TOUT_CMP
=
“YES”,
NOM_CHAM
=
“TEMP”,
LIST_INST
=
LINST_TH,
OPERATION
=
“EXTRACTION”,
)
)
After having taken these various readings, the calculation of the stress intensity factor can be done
indeed using control POST_K_BETA.
TB_KBETA = POST_K_BETA (MESH = MALL,
MATER_REV
=
MAME_RE2,
EPAIS_REV
=
EPREV,
FISSURE =
_F
(
DEPTH
=
6.,
LENGTH
=
60.,
SHIFT
=
- 1.E-05,
ORIENTATION=
“CIRC”
),
K1D
= (_F (TABL_MECA_REV = S1_G,
TABL_MECA_MDB
=
S2-G,
TABL_THER
=
TEMP_G,
ENTITLE
=
“NOEINF”,),),
TITRATE
=
'FIC
BY
METHOD
K-BETA'
)
Code_Aster
®
Version
7.4
Titrate:
Operator
POST_K_BETA
Date:
08/02/05
Author (S):
A. DAHL,
S. BUGAT, R. FERNANDES
Key
:
U4.82.07-B
Page
:
6/6
Instruction manual
U4.8- booklet: Postprocessing and dedicated analyzes
HT-66/05/004/A
Intentionally white left page.