3. Modeling A#
3.1. Characteristics of modeling#
3.2. Characteristics of the mesh and the finite element model#
The mesh consists of 1860 nodes and 1800 quadrangular meshes on which shell DKT elements are assigned.
3.3. Tested sizes and results#
Natural frequencies \((\mathit{Hz})\)
Only frequencies and modes with an effective mass greater than \(\text{0.1\%}\) are shown in the table below.
Mode Number |
Ref (SAMCEF) |
Code_Aster |
Gap |
Gap between SAMCEF and Code_Aster in % |
1 (47) |
2.80058 |
2.80058 |
2.80065 |
0.003 |
2 (48) |
2.80058 |
2.80058 |
2.80065 |
0.003 |
3 (158) |
5.92549 |
5.92549 |
5.92490 |
-0.010 |
4 (159) |
5.92549 |
5.92549 |
5.92490 |
-0.010 |
These four modes make it possible to obtain a good representation of the mass in the direction of excitation since the cumulative effective masses in the directions \(x\) and \(y\) amount to \(\text{83.2\%}\).
Horizontal displacement \(x(m)\):
Altitude |
CA AND EM 2000 |
Aster_code |
Variance (%) |
|||
CQC |
SRSS |
CQC |
SRSS |
CQC |
SRSS |
|
13.3 |
1.318E-03 |
1.316E-03 |
1.538 E-03 |
1.432 E-03 |
16.653 |
8.740 |
26.8 |
1.484E-03 |
1.485E-03 |
2.853 E-03 |
2.669 E-03 |
92.155 |
79.744 |
40.3 |
1.898E-03 |
1.898E-03 |
4.456 E-03 |
4.249 E-03 |
134.714 |
123.819 |
49.4 |
2.4448E-03 |
2.442E-03 |
5.693 E-03 |
5.495 E-03 |
132.872 |
124.948 |
63.08 |
3.278E-03 |
3.275E-03 |
7.822 E-03 |
7.657 E-03 |
138.603 |
133.751 |
76.8 |
4.570E-03 |
4.568E-03 |
1.026 E-02 |
1.014 E-02 |
124.510 |
121.860 |
90.7 |
5.918E-03 |
5.918E-03 |
1.293 E-02 |
1.283 E-02 |
118.516 |
116.802 |
100 |
7.023E-03 |
7.024E-03 |
1.477 E-02 |
1.467 E-02 |
110.294 |
108.862 |
109.3 |
7.677E-03 |
7.677E-03 |
1.658 E-02 |
1.648 E-02 |
115.998 |
114.614 |
127.9 |
9.053E-03 |
9.054E-03 |
1.990 E-02 |
1.975 E-02 |
119.818 |
118.117 |
Vertical displacement \(z(m)\):
Altitude |
CASTEM 2000 |
Aster_code |
Variance (%) |
|||
CQC |
SRSS |
CQC |
SRSS |
CQC |
SRSS |
|
13.3 |
4.534E-04 |
4.540E-04 |
8.297 E-04 |
8.101 E-04 |
82.955 |
78.407 |
26.8 |
6.832E-04 |
6.832E-04 |
1.712 E-03 |
1.674 E-03 |
150.528 |
145.025 |
40.3 |
1.091E-03 |
1.091E-03 |
2.464 E-03 |
2.408 E-03 |
125.872 |
120.680 |
49.4 |
1.510E-03 |
1.510E-03 |
2.892 E-03 |
2.823 E-03 |
91.521 |
86.877 |
63.08 |
1.794E-03 |
1.795E-03 |
3.424 E-03 |
3.337 E-03 |
90.769 |
85.848 |
76.8 |
1.944E-03 |
1.945E-03 |
3.840 E-03 |
3.737 E-03 |
97.437 |
92.035 |
90.7 |
2.024E-03 |
2.025E-03 |
4.173 E-03 |
4.056 E-03 |
106.143 |
100.213 |
100 |
2.114E-03 |
2.115E-03 |
4.372 E-03 |
4.244 E-03 |
106.767 |
100.630 |
109.3 |
2.187E-03 |
2.188E-03 |
4.564 E-03 |
4.427 E-03 |
108.645 |
102.266 |
127.9 |
2.356E-03 |
2.358E-03 |
4.959 E-03 |
4.803 E-03 |
110.427 |
103.663 |
3.4. notes#
The calculation is carried out without taking into account the neglected modes. In direction \(Z\), a single mode, No. 196, with a frequency lower than \(7\mathit{Hz}\), has an effective mass greater than \(0.1\text{\%}\)