Code_Aster ®
Version
6.0
Titrate:
SSLL108 - Eléments discrete 2D


Date:
19/08/02
Author (S):
J.M. PROIX, G. BERTRAND Clé
:
V3.01.108-A Page:
1/4

Organization (S): EDF/AMA, CS IF

Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
Document: V3.01.108

SSLL108 - Eléments discrete 2D

Summary:

The problem is quasi-static linear in mechanics of the structures.

One analyzes the response of a bar, modelled by 10 discrete elements, with a loading of traction, for
to validate the two-dimensional discrete elements.

Only one modeling uses at the same time operators MECA_STATIQUE, and STAT_NON_LINE, to validate
the use of these elements (of which the behavior remains linear) with other finite elements with behavior
unspecified.

Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A

Code_Aster ®
Version
6.0
Titrate:
SSLL108 - Eléments discrete 2D


Date:
19/08/02
Author (S):
J.M. PROIX, G. BERTRAND Clé
:
V3.01.108-A Page:
2/4

1
Problem of reference

1.1 Geometry

A bar L=10m length, along axis X, modelled by 10 discrete elements with 2 nodes.

1.2
Material properties

Each discrete element has a stiffness: K = 1.000 NR/m

1.3
Boundary conditions and loadings

In x=0
dx = Dy = 0
In x=L
Fx=10N

2
Reference solution

2.1
Method of calculation used for the reference solution

Analytical solution: displacement for an element is given by:
Ux=F/Kx

Thus for N springs: Ux = N F/Kx

2.2
Results of reference

Values of displacement for x=L/2 and X=L, as well as effort in the elements (constant):

U (L/2) = 0.05 m, U (L) = 0.1 m, N=10N

2.3
Uncertainty on the solution

Exact analytical solution.

Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A

Code_Aster ®
Version
6.0
Titrate:
SSLL108 - Eléments discrete 2D


Date:
19/08/02
Author (S):
J.M. PROIX, G. BERTRAND Clé
:
V3.01.108-A Page:
3/4

3 Modeling
With

3.1
Characteristics of modeling

Modeling 2d_DISCRET

3.2
Characteristics of the grid

10 meshs SEG2.

3.3 Functionalities
tested

Order
Key word factor
Simple key word
Argument
AFFE_CARA_ELEM
DISCRET
K_T_D_L
MECA_STATIQUE
STAT_NON_LINE
COMP_INCR
RELATION
ELAS
CALC_ELEM

OPTION
SIEF_ELGA_DEPL

OPTION
SIEF_ELGA_DEPL

4
Results of modeling A

4.1 Values
tested

Identification Reference
Aster %
difference
MECA_STATIQUE



DX (L/2)
0.05 0.05 0s
DX (L)
0.1.0.1 0
NR (SIEF_ELGA_DEPL)
10 10 0
STAT_NON_LINE



DX (L/2)
0.05 0.05 0s
DX (L)
0.1.0.1 0
NR (SIEF_ELGA)
10 10 0

Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A

Code_Aster ®
Version
6.0
Titrate:
SSLL108 - Eléments discrete 2D


Date:
19/08/02
Author (S):
J.M. PROIX, G. BERTRAND Clé
:
V3.01.108-A Page:
4/4

5
Summary of the results

This very simple test voluntarily makes it possible to check the correct operation of the discrete elements 2D
with STAT_NON_LINE, which makes it possible to use them with other modelings.
Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A

Outline document