PSI - Issue 36

Mykhailo Hud et al. / Procedia Structural Integrity 36 (2022) 79–86 Mykhailo Hud / Structural Integrity Procedia 00 (2021) 000 – 000

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calculation (Fig. 4). Initial data for seismic calculation VST -4500 m 3 : diameter of the tank ( D ) – 20 m ; height of the tank wall (H) – 15 m ; the ratio ; density of stored product, gasoline - 850 kg /m 3 ; area with seismicity of 7 points; steel grade S325 (sheets 3 m × 10 m ) MPa , MPa ; thickness of steel on belts of a wall of the tank: I belt below - 14 mm steel; II belt below - 14 mm steel; III belt below - 14 mm steel; IV belt below - 12 mm steel; V belt at the bottom - 12 mm steel; GPa and Poisson's ratio . 3. Results and discussing In the software package "LIRA" a computer experiment was performed, in which the indicators of the stress strain state of the model of a steel cylindrical tank under seismic influence were revealed. According to the results of the experiment, 4 forms of oscillations were obtained, 2 of which will be given and compared in this paper. The results of the determination of frequency characteristics are given in Table 1. Table 1. Frequencies of natural oscillations # Loading # Form Own values Frequencies Period(s) Partition coefficient Modal mass (%)

The sum of modal mass (%)

Circular frequency (Rad/s)

Frequency (Hz)

2 2 2 2 2

1 2 3 4 5

130.81 107.66 17.47

0.008 0.009 0.057 0.104 0.112

0.001 0.001 0.009 0.016 0.018

821.89 676.45 109.76 60.62 59.19

0.0668 0.340 -0.759 -0.456 0.050

22.76 1.77 9.99

22.76 24.54 34.53 37.93 37.97

9.65 8.94

3.4

0.044

According to the results of a computer experiment, the values and distribution of stresses (Fig. 5-8) in a vertical steel cylindrical tank under the action of seismic effects were obtained.

c)

b)

а)

d)

f)

e)

g)

Figure 5. Stress isopoles of a steel cylindrical tank: stress isopoles of

;stress isopoles of ;b) stress isopoles of ;stress isopoles of ;

;stress isopoles of ; d) stress isopoles of

.

c) stress isopoles of