Code_Aster
®
Version
5.0
Titrate:
SSLL110 - System 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
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A
Organization (S)
: EDF/AMA
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
Document: V3.01.110
SSLL110 - System 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 stresses.
Code_Aster
®
Version
5.0
Titrate:
SSLL110 - System 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
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A
1
Problem of reference
1.1 Geometry
A system of 3 bars out of U:
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. 10
11
AP for the 3 bars.
Rho=8000 kg/m
3
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= 4.10
5
NR
·
displacements out of C and D: Uy=2 10
- 5
m
2.3
Uncertainty on the solution
Analytical solution.
B
D
C
With
X
y
Code_Aster
®
Version
5.0
Titrate:
SSLL110 - System 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
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A
3 Modeling
With
3.1
Characteristics of modeling
Each bar is modelized by only one element.
3.2
Characteristics of the mesh
Three meshs SEG2.
3.3 Functionalities
tested
Controls
AFFE_CARA_ELEM
BAR
AFFE_CHAR_MECA
GRAVITY
CALC_ELEM
“EFGE_ELNO_DEPL”
4
Results of modeling A
4.1 Values
tested
Identification Reference Aster %
difference
U
X
(C)
2 10
5
2
10
5
0
U
X
(C)
2 10
5
2
10
5
0
NR (AC) 4.10
5
4.10
5
0
NR (DATA BASE) 4.10
5
4.10
5
0
Code_Aster
®
Version
5.0
Titrate:
SSLL110 - System 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
Manual of Validation
V3.01 booklet: Linear statics of the linear structures
HT-66/02/001/A
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 `a fault on gravity into the bars, and
allows to validate the correction.