4. B modeling#
4.1. 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.
4.2. Characteristics of the mesh#
Number of knots: 122
Number of meshes and types: 100 QUAD4
4.3. Tested sizes and results#
Identification |
Instants |
Reference |
Aster |
% difference |
Frequency (mode 4 out of plane) |
44.762 |
44.64 |
—0.273 |
|
Frequency (modes 5 & 6 off plan) |
110.52 |
108.04 108.26 |
—2.247 —2.041 |
|
Frequency (mode 7 out of plane) |
169.08 |
162.86 |
—3.681 |
|
Frequency (Mode 8 in the map) |
193.93 |
195.70 |
0.912 |
|
Frequency (mode 9 & 10 in the map) |
206.64 |
208.89 208.89 |
1.088 |
4.4. notes#
In Code_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 (\(\mathrm{Hz}\)) |
1 |
44.64 |
2 |
108.04 |
3 |
108.26 |
4 |
162.86 |
5 |
195.70 |
6 |
203.97 |
7 |
206.08 |
8 |
208.89 |
9 |
208.89 |
10 |
220.92 |
11 |
248.12 |
12 |
250.10 |
13 |
252.49 |
14 |
289.79 |