5. C modeling#
5.1. 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.
5.2. Characteristics of the mesh#
Number of knots: 122
Number of meshes and types: 200 TRIA3
5.3. Tested sizes and results#
Identification |
Instants |
Reference |
Aster |
% difference |
Frequency (mode 4 out of plane) |
44.762 |
47.358 |
5.799 |
|
Frequency (modes 5 & 6 off plan) |
110.52 |
118.029 118.059 |
6.795 6.822 |
|
Frequency (mode 7 out of plane) |
169.08 |
187.504 |
10.897 |
|
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 |
5.4. notes#
In Aster, the calculated modes are those of rigid bodies: the fourth reference mode is the first mode calculated by the*Code_Aster.
Appearance of two flexure modes after reference mode 11 (mode 8 of*Code_Aster), in the same form as those appeared in modeling DST between reference modes 8 and 9 (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 |
47.358 |
2 |
118.03 |
3 |
118.06 |
4 |
187.50 |
5 |
196.09 |
6 |
211.66 |
7 |
212.00 |
8 |
22.53 |
9 |
235.41 |
10 |
235.56 |
11 |
264.73 |
12 |
289.85 |
13 |
302.84 |
14 |
303.15 |