Code_Aster ®
Version
7.4
Titrate:
Operator DEFI_INTERF_DYNA


Date:
10/02/05
Author (S):
O. NICOLAS, E. BOYERE Key
:
U4.64.01-G Page
: 1/4

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

Handbook of Utilization
U4.6- booklet: Elementary matrices/Vecteurs and assembly
Document: U4.64.01

Operator DEFI_INTERF_DYNA

1 Goal

To define the interfaces of a structure and to affect a type to them.

Employed within the framework of methods of modal recombination, or dynamic under-structuring
by modal synthesis. Also count, without calculating them (task carried out by the operator
DEFI_BASE_MODALE [U4.64.02]), deformations static corresponding to the definite interfaces.

Product a structure of data of the interf_dyna_clas type.

Handbook of Utilization
U4.6- booklet: Elementary matrices/Vecteurs and assembly
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator DEFI_INTERF_DYNA


Date:
10/02/05
Author (S):
O. NICOLAS, E. BOYERE Key
:
U4.64.01-G Page
: 2/4

2 Syntax

inter [interf_dyna_clas] = DEFI_INTERF_DYNA


(NUME_DDL = naked
,
[nume_ddl]


INTERFACE=
_F (NOM

=

“nom_int”,
[KN]








TYPE
=
/“MNEAL”,
/
“CRAIGB”,
/
“CB_HARMO”,
/
“AUCUN”,
[DEFAUT]








/NOEUD
=
“lno”,
[l_noeud]









/GROUP_NO = “lgno”, [l_gr_noeud]








DDL_ACTIF
=
“lddl”, [l_cmp]








MASQUE
=
“lddl”, [l_cmp]







),



FREQ
=
/
val_freq,
[R8]






/1,
[DEFAUT]



INFO
=
/
1,
[DEFAUT]






/2,

)

Handbook of Utilization
U4.6- booklet: Elementary matrices/Vecteurs and assembly
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator DEFI_INTERF_DYNA


Date:
10/02/05
Author (S):
O. NICOLAS, E. BOYERE Key
:
U4.64.01-G Page
: 3/4

3 Operands

3.1 Operand
NUME_DDL

NUME_DDL = naked

Name of the concept nume_ddl of the structure.

3.2 Word
key
INTERFACE

INTERFACE

Key word factor for the definition of the interfaces.

3.2.1 Operand
NOM



NOM = “nom_int”

Name of the interface. It is obligatory for each interface. If for an occurrence of the word
key factor INTERFACE no name is given, then this occurrence comes to supplement
definition of the interface previously named (concatenation of the list of the nodes with
continuation of those already existing). This makes it possible to use key words NOEUD and GROUP_NO for
the same interface, or to give various arguments to key words MASQUE and
DDL_ACTIF within the same interface.

3.2.2 Operand
TYPE



TYPE =

It makes it possible to specify the kind of the modal base corresponding to the interface.

“MNEAL”
:

interface correspondent at a modal base of type MAC-NEAL which includes/understands
clean modes and of the modes of fastener. The modes of fastener are not entered, with
the interface, that on the not blocked and not masked degrees of freedom.

“CRAIGB”
:

interface correspondent at a modal base of type CRAIG-BAMPTON which includes/understands
clean modes and constrained modes. The constrained modes are not
entered, with the interface, that on the degrees of freedom blocked by dualisation and not
masked.

“CB_HARMO”
:

interface correspondent at a modal base of harmonic type CRAIG_BAMPTON which
includes/understands clean modes and constrained harmonic modes (displacement
unit imposed harmonic). The frequency used is that given in argument of the word
key frequency “FREQ”.

The harmonic constrained modes are not entered, with the interface, that on
degrees of freedom blocked by dualisation and not masked.

“AUCUN”
:

free interface. No static deformation will be calculated; the modal base
will comprise that clean modes.
Handbook of Utilization
U4.6- booklet: Elementary matrices/Vecteurs and assembly
HT-66/05/004/A

Code_Aster ®
Version
7.4
Titrate:
Operator DEFI_INTERF_DYNA


Date:
10/02/05
Author (S):
O. NICOLAS, E. BOYERE Key
:
U4.64.01-G Page
: 4/4

3.2.3 Operands
NODE/GROUP_NO



NOEUD = “lno”

List ordered nodes of the grid composing the interface. The use of the key words
NOEUD and GROUP_NO are exclusive in the same occurrence of the key word factor INTERFACE.



GROUP_NO = “lgno”

List ordered groups of nodes of the grid composing the interface. The final list of
nodes is obtained by concatenation of the groups of nodes in the order given by
the user, at the time of the definition of the groups.

3.2.4 Operands
DDL_ACTIF/MASK



DDL_ACTIF = “lddl”

List active degrees of freedom to the interface. Conditions of continuity of displacements
between the two interfaces of two structures will be expressed only on the degrees of
freedom credits (it is thus necessary to take care of coherence definitions of two interfaces intended for
to be connected). By defect if the key word does not appear, all the degrees of freedom are
regarded a priori as credits. List of the active degrees of freedom given by
the user are withdrawn the blocked degrees of freedom (ddl blocked of an interface of the MAC type
NEAL or ddl masked of an interface of the type CRAIG-BAMPTON).



MASQUE = “lddl”

List ddl for the current nodes which should not generate static deformations
(ddl masked).

3.3 Operand
FREQ


FREQ = val_freq

Value of the frequency used for the calculation of the harmonic constrained modes.

3.4 Operand
INFO


INFO =

Level of information provided in file “MESSAGE”:

1
no impression,
2
writing of the definitions of the interfaces (kind, nodes), and of the static deformations
listed (allows to properly check the list of the static deformations before their calculation
known as).

3.5
Case of a node common to several interface

When a node is common to several interfaces (for example the center of a circular structure),
that often leads to a singular system in the calculation of the clean modes of the complete structure.
One circumvents this problem by eliminating the common node. That led of course to an error on
total modes but if the grid is rather fine, it is not sensitive (see the case test SDLS01).

4 Example

An example of use of the command is given in the documentation of the operator
DEFI_SQUELETTE [U4.24.01].
Handbook of Utilization
U4.6- booklet: Elementary matrices/Vecteurs and assembly
HT-66/05/004/A

Outline document