Code_Aster ®
Version
7.4
Titrate:
Operator COMB_CHAM_ELEM


Date:
04/01/05
Author (S):
X. DESROCHES, L. VIVAN Key
:
U4.72.03-G Page
: 1/6

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

Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
Document: U4.72.03

Operator COMB_CHAM_ELEM

1 Goal

To carry out the linear combination of fields to the elements.

All the concepts of the cham_elem_ type * to combine must be of the same structure (same lists
groups of elements, to come from the same option of calculation).

This operator is also used to carry out the recombination of modes of Fourier in a direction
data (for the strains and stresses in mechanics, flows in thermics).

The produced concept (cham_elem_ *) can be réentrant.

Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator COMB_CHAM_ELEM


Date:
04/01/05
Author (S):
X. DESROCHES, L. VIVAN Key
:
U4.72.03-G Page
: 2/6

2 Syntax

chml
[cham_elem_ *] = COMB_CHAM_ELEM
(

reuse = chml,

/COMB_R=_F (CHAM_ELEM= CH,/[cham_elem_SIEF_R]
/
[cham_elem_FLUX_R]
/
[cham_elem_EPSI_R]
/
[cham_elem_ENER_R]
/
[cham_elem_CRIT_R]
/
[cham_elem_DBEL_R]
/
[cham_elem_PRES_R]
/
[cham_elem_SIEF_C]








COEF_R=
R
,
[R]







“REAL” PARTIE=/
, [K]
/
“IMAG”
,






),
/
COMB_C
=_F (

CHAM_ELEM
=
CH,
/
[cham_elem_SIEF_R]
/
[cham_elem_SIEF_C]








/
COEF_R=
R
,
[R]
/
COEF_C=
C
,
[C]






),
/
COMB_FOURIER
=_F (CHAM_ELEM = CH,
/[cham_elem_SIEF_R]
/
[cham_elem_FLUX_R]
/
[cham_elem_EPSI_R]









NUME_MODE=
nume,
[I]









TYPE_MODE=/“SYME”, [K]













/“ANTI”,









COEF_R=/
R
,
[R]













/1.,

[DEFAUT]








),




ANGL
=
Eng
[R]












)

if COMB_R and CHAM_ELEM
:
[cham_elem_SIEF_R]
then [*]
- > SIEF_R
[cham_elem_FLUX_R]
[*]
- > FLUX_R
[cham_elem_EPSI_R]
[*]
- > EPSI_R
[cham_elem_ENER_R]
[*]
- > ENER_R
[cham_elem_CRIT_R]
[*]
- > CRIT_R
[cham_elem_DBEL_R]
[*]
- > DBEL_R
[cham_elem_PRES_R]
[*]
- > PRES_R
[cham_elem_SIEF_C]
[*]
- > SIEF_R

if COMB_C and CHAM_ELEM
:
[cham_elem_SIEF_R]
then [*]
- > SIEF_C
[cham_elem_SIEF_C]
[*]
- > SIEF_C

if COMB_FOURIER and CHAM_ELEM:
[cham_elem_SIEF_R] then [*]
- > SIEF_R
[cham_elem_FLUX_R]
[*]
- > FLUX_R
[cham_elem_EPSI_R]
[*]
- > EPSI_R

Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator COMB_CHAM_ELEM


Date:
04/01/05
Author (S):
X. DESROCHES, L. VIVAN Key
:
U4.72.03-G Page
: 3/6

3 Operands

3.1
Recall on the syntax of the complex values

The complex values can be declared in two different ways:

·
in the form
+ ib with syntax IH has has, B
where
has and B are real numbers.
·
in the form
(module, phase) with MP modulates, phase
where
modulate and phase are real numbers (phase in degree).

3.2 Word
key
COMB_R

/COMB_R = _F

Description of the terms of the linear combination producing a cham_elem_ * with coefficients
realities.



CHAM_ELEM = CH,

Name of the concept of the cham_elem_ type * to combine.



COEF_R = R,

Real coefficient to apply to the CH concept.



PARTIE
=

In the case of complex CHAM_ELEM, one takes the real or imaginary part.

3.3 Word
key
COMB_C


/COMB_C = _F

Description of the terms of the linear combination producing a cham_elem_ * with values
complexes.



CHAM_ELEM = CH,

Name of the concept of the cham_elem_ type * to combine.



/COEF_R = R,

Real coefficient to apply to the CH concept.

/
COEF_C
=
C,

Coefficient complexes to apply to the concept argument of CHAM_ELEM.
Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator COMB_CHAM_ELEM


Date:
04/01/05
Author (S):
X. DESROCHES, L. VIVAN Key
:
U4.72.03-G Page
: 4/6

3.4 Word
key
COMB_FOURIER


/
COMB_FOURIER = _F

Recombination of FOURIER with harmonic description by harmonic of the terms of
Fourier series.

In elasticity, recombination of FOURIER on the deformations (resp. constraints)
is written:



L I4
04,2
sinl I4
04,2

() =

cos

S +
has
L


0
sin L I
0
cosl I
L

L L
-



2,4
2

2,4
2


where L is the whole of the modes (symmetrical and/or antisymmetric) which were calculated.

In is the matrix identity of command N,

SSL: L is the number of the harmonic (S for symmetrical),

Al: L is the number of the harmonic (has for antisymmetric),

: angle of the section where the deformations (resp are calculated. constraints).

In the formula above, all the coefficients R are worth 1. (standard case).

In thermics, the recombination of FOURIER on flows is written:


L I2
02,1
sinl I2
02,1

() =

cos

S +
has
L


0
sin L
0
cosl
L

L L
-



,
1 2


,
1 2



with the same notations as above.

3.4.1 Operand
CHAM_ELEM



CHAM_ELEM = CH,

Name of the concept of the cham_elem_ type * to recombine.

3.4.2 Operand
COEF_R




COEF_R = R,

Real coefficient to apply to the harmonic considered (by defect 1.)

3.4.3 Operand
NUME_MODE



NUME_MODE = nume,

Number of the harmonic.

3.4.4 Operand
TYPE_MODE



TYPE_MODE =/“SYME”,







/
“ANTI”,

Harmonic SYMEtrique or ANTIsymétrique.

3.5 Operand
ANGL



ANGL = Eng,

Angle in degree where the recombination of FOURIER takes place.
Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator COMB_CHAM_ELEM


Date:
04/01/05
Author (S):
X. DESROCHES, L. VIVAN Key
:
U4.72.03-G Page
: 5/6

4
Phases of checking/execution

Phase of checking

It is checked that the “produced concept” is not an operand of input of the operator.

Production run

·
With the execution the operator checks before carrying out the linear combination, that the type of
values of the result is compatible with the type of the values of the concepts cham_elem_ * with
to combine.

·
The checks of coherence are also carried out: arguments of the cham_elem_ type *
must have same the ligrels, i.e. to be calculated on the same lists of
groups of elements.

5 Examples
5.1
Traditional linear combination

Utot = COMB_CHAM_ELEM (COMB_C = (_F (CHAM_ELEM= U1, COEF_R =1.),
_F (CHAM_ELEM
=U2,
COEF_C
=RI
0.,
1.),),







)

The concept produces Utot is of cham_elem_ type * _C (complex):

Utot = U1 + I U2

The Utot concept can be used again as concept produced for a new combination
with U3 cham_elem_ * _R (real):

Utot = COMB_CHAM_ELEM (reuse = Utot,
COMB_C = (_F
(CHAM_ELEM = Utot, COEF_R = 1.),


_F (CHAM_ELEM
=
U3,


COEF_R
=
2.),),







)

What produces:

Utot = Utot + 2. U3

5.2
Recopy concept of the cham_elem type

CH_sauv = COMB_CHAM_ELEM (COMB_R = _F (CHAM_ELEM = CH, COEF_R = 1.)
)

5.3
Recombination of FOURIER in elasticity

sig45 = COMB_CHAM_ELEM
(COMB_FOURIER=
(_F (CHAM_ELEM = sig1,
NUME_MODE
=
1,
TYPE_MODE
=
“SYME”
,),













_F (CHAM_ELEM = sig2,
NUME_MODE
=
0,
TYPE_MODE
=
“ANTI”
,),
ANGLE
=
45.,








)

One calculates the recombination of FOURIER of a stress field for the section = 45. of one
harmonic resulting from a loading symmetrical mode 1 and a harmonic resulting from one
loading in pure torsion (antisymmetric mode 0).
Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator COMB_CHAM_ELEM


Date:
04/01/05
Author (S):
X. DESROCHES, L. VIVAN Key
:
U4.72.03-G Page
: 6/6

5.4
Recombination of FOURIER in thermics

flux0 = COMB_CHAM_ELEM
(COMB_FOURIER=
(_F (CHAM_ELEM = flux1,
NUME_MODE
=
1,
TYPE_MODE
=
“SYME”
,),













_F (CHAM_ELEM = flux2,
NUME_MODE
=
2,
TYPE_MODE
=
“SYME”
,),
ANGLE
=
0.,








)

One calculates the recombination of FOURIER for the section = 0. of 2 symmetrical modes: mode 1 and
mode 2.

Each field of flow (flux1 and flux2) comes from a resolution on the mode considered.
Handbook of Utilization
U4.7- booklet: Operations on the results and the fields
HT-66/05/004/A

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