Code_Aster ®
Version
5.0
Titrate:
SSLL110 - Système of 3 bars out of U under actual weight

Date:
23/09/02
Author (S):
J.M. PROIX
Key: V3.01.110-A Page: 1/4

Organization (S): EDF/AMA
Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
Document: V3.01.110

SSLL110 - Système of 3 bars out of U under weight
clean

Summary:

This test allows a simple checking of calculations of gravity for the elements of bar in mechanics of
structures linear statics. The model is linear.

Only one modeling is used: it makes it possible to test the application of gravity on elements of
bar, located in a reference mark different from the direction of gravity.

The values tested are the generalized displacements, efforts and the constraints.
Handbook of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A

Code_Aster ®
Version
5.0
Titrate:
SSLL110 - Système of 3 bars out of U under actual weight

Date:
23/09/02
Author (S):
J.M. PROIX
Key: V3.01.110-A Page: 2/4

1
Problem of reference

1.1 Geometry

A system of 3 bars out of U:

B

With

y

D
X

C

The surface of the cross sections is worth A=1m ². The length of each of the 3 bars is worth L=10m.

1.2
Material properties

E = 2. 1011 Pa for the 3 bars.
Rho=8000 kg/m3 only for the bar CD. For the 2 other bars, Rho=0.

1.3
Boundary conditions and loadings

Embedding in A and B.
In order to avoid the movements of rigid body, DZ=0 for all the nodes, and DX=0 out of C and D.

1 only loading is applied: gravity, with g=2m/s ², in the direction (0.866, - 0.5, 0), which

to G = 10m/s ² is equivalent, in the direction there.

2
Reference solution

2.1
Method of calculation used for the reference solution

· Analytical solution:

Normal effort in each bar AC and data base: N=Rho * L * A * G/2

Uy displacement out of C and D: Uy=NL/ES

2.2
Results of reference

· Normal bar tension AC and data base: N= 4.105 NR
· displacements out of C and D: Uy=2 10-5m

2.3
Uncertainty on the solution

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

Code_Aster ®
Version
5.0
Titrate:
SSLL110 - Système of 3 bars out of U under actual weight

Date:
23/09/02
Author (S):
J.M. PROIX
Key: V3.01.110-A Page: 3/4

3 Modeling
With

3.1
Characteristics of modeling

Each bar is modelled by only one element.

3.2
Characteristics of the grid

Three meshs SEG2.

3.3 Functionalities
tested

Commands



AFFE_CARA_ELEM
BARRE

AFFE_CHAR_MECA
PESANTEUR

CALC_ELEM
“EFGE_ELNO_DEPL”


4
Results of modeling A

4.1 Values
tested

Identification Reference Aster %
difference
ux (C)
2 10­5 2
10­5 0
ux (C)
2 10­5 2
10­5 0
NR (AC) 4.105 4.105 0
NR (DATA BASE) 4.105 4.105 0

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

Code_Aster ®
Version
5.0
Titrate:
SSLL110 - Système of 3 bars out of U under actual weight

Date:
23/09/02
Author (S):
J.M. PROIX
Key: V3.01.110-A Page: 4/4

5
Summary of the results

This test, very simple, makes it possible simultaneously to check the correct operation of gravity in
elements of bar, which is checked by the perfect coincidence of the results with the solution
analytical. It was introduced following the discovery D `an anomaly on gravity into the bars, and
allows to validate the correction.

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

Outline document