7. E modeling#
7.1. 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.
7.2. Characteristics of the mesh#
Number of knots: 122
Number of meshes and types: 200 TRIA6
7.3. Tested sizes and results#
Identification |
Instants |
Reference |
Aster |
% difference |
Frequency (mode 4 out of plane) |
44.762 |
43.867 |
2.00 |
|
Frequency (modes 5 & 6 off plan) |
110.52 |
106.058 |
||
106.066 » |
—4.037 —4.029 |
|||
Frequency (mode 7 out of plane) |
169.08 |
160.010 |
—5.305 |
|
Frequency (Mode 8 in the map) |
193.93 |
193.600 |
—0.170 |
|
Frequency (mode 9 & 10 in the map) |
206.64 |
206.209 206.211 |
0.208 0.207 |
7.4. 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 are modes 6 and 7 of*Code_Aster.
In the table below we have reported the first 14 natural frequencies found.
Mode No. |
Frequency (\(\mathrm{Hz}\)) |
1 |
43,867 |
2 |
106.06 |
3 |
106.07 |
4 |
160.11 |
5 |
186,72 |
6 |
193.60 |
7 |
199.76 |
8 |
200.23 |
9 |
206.21 |
10 |
206.21 |
11 |
219.28 |
12 |
245.91 |
13 |
245.94 |
14 |
249.27 |