6. D modeling#
6.1. 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.
6.2. Characteristics of the mesh#
Number of knots: 122
Number of meshes and types: 100 QUAD4
6.3. Tested sizes and results#
Identification |
Instants |
Reference |
Aster |
% difference |
|
Frequency (mode 4 out of plane) |
44.762 |
47.182 |
5.408 |
||
Frequency (modes 5 & 6 off plan) |
110.52 |
117.463 |
6.283 |
||
Frequency (mode 7 out of plane) |
169.08 |
184.746 |
9.266 |
||
Frequency (Mode 8 in the map) |
193.93 |
195.699 |
0.912 |
||
Frequency (mode 9 & 10 in the map) |
206.64 |
208.887 |
1.088 |
6.4. 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 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 |
47.183 |
2 |
117.46 |
3 |
117.46 |
4 |
184.75 |
5 |
195.70 |
6 |
208.89 |
7 |
208.89 |
8 |
220.92 |
9 |
234.74 |
10 |
234.74 |
11 |
252.49 |
12 |
289.79 |
13 |
297.27 |
14 |
297.27 |