3. Modeling A#
3.1. Characteristics of modeling#
To validate the modeling in a coordinate system different from the global coordinate system, the plate is rotated by \(\mathrm{15,5}°\). This should not change the natural frequencies obtained.
3.2. Characteristics of the mesh#
Number of knots: 122
Number of meshes and types: 200 TRIA3
3.3. Tested sizes and results#
Identification |
Instants |
Reference |
Aster |
% difference |
Frequency (mode 4 out of plane) |
44.762 |
44.989 |
0.507 |
|
Frequency (modes 5 & 6 off plan) |
110.52 |
107.608 107.880 |
—2.634 —2.388 |
|
Frequency (mode 7 out of plane) |
169.08 |
165.454 |
—2.144 |
|
Frequency (Mode 8 in the map) |
193.93 |
196.089 |
1.114 |
|
Frequency (mode 9 & 10 in the map) |
206.64 |
211.658 212.000 |
2.428 2.594 |
3.4. notes#
In Aster, the calculated modes are rigid body modes: the fourth reference mode is the first mode calculated by*Code_Aster.
Appearance of two flexure modes between reference modes 8 and 9: these modes are modes 6 and 7 of*Code_Aster.
In the table below we have reported the first 14 natural frequencies found.
Mode No. |
Frequency (Hz) |
1 |
44,98 |
2 |
107.61 |
3 |
107.88 |
4 |
165.45 |
5 |
196.09 |
6 |
202.80 |
7 |
203.54 |
8 |
211.66 |
9 |
212.00 |
10 |
222.53 |
11 |
254.74 |
12 |
255.62 |
13 |
264.73 |
14 |
289.85 |