background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
1/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
Organization (S):
EDF-R & D/AMA















Manual of Validation
V3.01 booklet: Linear statics of the linear structures
V3.01.116 document



SSLL116 - Lattice reinforced 3D




Summary:

This test relates to the study of a lattice made up of hurled beams, in linear static analysis.

The lattice is modelized with elements linear (SEG2) and subjected to a specific loading and the effect of
gravity.

There is a modeling with a first geometry, then a modeling with bars of reinforcement.

This test is an example with didactic sighting since it shows the construction of the solution by finite elements rather
to use MECA_STATIQUE directly.
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
2/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
1
Problem of reference
1.1 Geometry


























The lattice consists of annular beams of sections everywhere (R=0.05, ep=0.02), except on the part
“crane”, made up of circular sections of two sizes: R=0.05 for the full rounds and R=0.07
for the hatched round.
Point A is in the middle of the final stem.

1.2
Material properties
Isotropic linear elastic material:
E = 1.962 E11 AP;=0.3

1.3
Boundary conditions and loadings
The base of the lattice is embedded.
Loadings
Vertical nodal force in a:
F
y
= ­ 20e6 NR
Field of gravity (according to X)
G = ­ 9.81 m/s ²
X
Y
Z
7
7
2,8
21
0,7
1,05
With
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
3/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
2
Reference solution
2.1
Results of reference
Displacements and rotations of node A (DEPL).
The results calculated in this case test result from a former execution of Aster. It is a case test
of nonregression.
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
4/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
3 Modeling
With
3.1
Characteristics of modeling




















·
Modeling
POU_D_T
·
No reinforcements
3.2
Characteristics of the mesh
The mesh is obtained by GMSH.
A number of nodes:
247
A number of meshs:
267
3.3 Functionalities
tested
Controls Options
PRE_GMSH
LIRE_MAILLAGE
DEFI_MATERIAU ELAS
AFFE_MATERIAU ALL
AFFE_MODELE
“MECHANICAL” “POU_D_T'
DEFI_VALEUR
AFFE_CARA_ELEM
BEAM “RINGS”
AFFE_CHAR_MECA DDL_IMPO
FORCE_NODALE
CALC_MATR_ELEM “RIGI_MECA”
CALC_VECT_ELEM “CHAR_MECA”
NUME_DDL MATR_RIGI
ASSE_MATRICE
ASSE_VECTEUR
FACT_LDLT
RESO_LDLT
DEFUFI
IMPR_RESU “GMSH”
TEST_RESU “NON_REGRESSION”
X
Y
Z
7
7
2,8
21
0,7
1,05
With
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
5/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
4
Results of modeling A
4.1 Values
tested
Loading Value
tested
Aster
Force concentrated vertical in A
Displacement of A Dx
7,20564x10
­ 1
Displacement of A Dy
­ 2,02277x10
­ 0
Displacement of A Dz
­ 1,12417x10
­ 0
Rotation of A Drx
9,88004x10
­ 1
Rotation of A Dry
1,83637x10
­ 1
Rotation of A Drz
­ 1,12592x10
­ 1
4.2 Remarks
It is seen that the not-symmetry of the arrow of the lattice involves displacements according to Z, although
force applied is it according to Y and X only (force of gravity)
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
6/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
5 Modeling
B
5.1
Characteristics of modeling




















·
Modeling
POU_D_T
·
Bars of reinforcement
5.2
Characteristics of the mesh
The mesh is obtained by GMSH.
A number of nodes:
265
A number of meshs:
287
5.3 Functionalities
tested
Controls Options
PRE_GMSH
LIRE_MAILLAGE
DEFI_MATERIAU ELAS
AFFE_MATERIAU ALL
AFFE_MODELE
“MECHANICAL” “POU_D_T'
DEFI_VALEUR
AFFE_CARA_ELEM
BEAM “RINGS”
AFFE_CHAR_MECA DDL_IMPO
FORCE_NODALE
CALC_MATR_ELEM “RIGI_MECA”
CALC_VECT_ELEM “CHAR_MECA”
NUME_DDL MATR_RIGI
ASSE_MATRICE
ASSE_VECTEUR
FACT_LDLT
RESO_LDLT
DEFUFI
IMPR_RESU “GMSH”
TEST_RESU “NON_REGRESSION”
X
Y
Z
7
7
2,8
21
0,7
1,05
With
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
7/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
6
Results of modeling B
6.1 Values
tested
Loading Value
tested
Aster
Force concentrated vertical in A
Displacement of A Dx
6,61627x10
­ 1
Displacement of A Dy
­ 1,82145x10
­ 0
Displacement of A Dz
­ 2,6628x10
­ 1
Rotation of A Drx
8,48048x10
­ 1
Rotation of A Dry
1,68397x10
­ 1
Rotation of A Drz
­ 9,43511x10
­ 2
6.2 Remarks
The reinforcements made it possible to decrease displacements of the arrow of the lattice.
background image
Code_Aster
®
Version
7.1
Titrate:
SSLL116 - Lattice articulated 3D
Date
:
23/09/03
Author (S):
Mr. ABBAS
Key
:
V3.01.116-A
Page:
8/8
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/03/008/A
7
Summary of the results
This example shows a way of carrying out the “didactic” calculation of manner while building
explicitly vectors and matrices necessary for a standard calculation by finite elements.