## 3 Analysis of Test Results
### Numerical Simulation of Experimental Tank Model
The established numerical model of the test storage tank is shown in Figure 8.  
In order to make the seismic waves input by the numerical model consistent with the seismic waves input by the test, the acceleration time history record of the shaking table is used as the seismic excitation of the numerical model. Considering that there are many experimental conditions, some experimental conditions are selected for numerical simulation to compare experimental results and numerical calculation results. This paper takes the El Centro wave as an example. We selected the measuring points located on the side wall of the outer tank to compare the results, namely measuring points 2-5 and measuring points 10-13. Figure 9 shows the comparison of acceleration time history curve and spectral characteristics of the seismic storage tank and the corresponding numerical model, and the following conclusions can be drawn:  
1. Comparing the acceleration time history curve, it can be seen that the acceleration responses of them are very close. As the height of the measuring point increases, the amplitude difference among the results of them increases, but the changing trend of the acceleration response is consistent. This shows that the calculation results of the numerical model can reflect the acceleration response of the seismic storage tank. 2. Comparing the spectral characteristic curves, it can be seen that the spectral characteristic curves of the two are not much different, especially in the range of 0-30 Hz; indeed, the results of the two are almost the same. The spectral characteristic curves of the seismic storage tank and the numerical model have two obvious peaks, and the peak points are located around 8 Hz and 32 Hz, respectively. The first peak corresponds exactly to the predominant frequency of the El Centro wave. Furthermore, as the height of measuring point increases, the second peak becomes more pronounced. From the comparison in the frequency domain, the calculation results of the numerical model can also reflect the spectral characteristics of the acceleration response of the seismic storage tank. Figure 10 shows the comparison of acceleration time history and spectral characteristics of the isolation storage tank and the numerical model. It is similar to the results of the seismic tank; however, there are some differences, mainly in the spectral characteristics. There are still two obvious peaks in the acceleration spectrum characteristic curve of the seismically isolated storage tank. Compared with the seismic storage tank, the amplitude of the second peak of the isolation storage tank is significantly reduced. This may be due to  
Figure 8: Finite element model of the LNG storage tank. the introduction of lead-core rubber mounts to the tank, which reduces the high-frequency vibration of the tank. Based on the numerical simulation analysis of the test tank, it can be confirmed that the seismic response of the numerical simulation results is close to that of the test results, and the fitting degree of their spectral characteristic curves is also very good, which verifies the rationality and effectiveness of the numerical model. The numerical model of this paper can be used for seismic response analysis of large LNG storage tanks. Figure 9: Comparison results of the seismic storage tank under El Centro (X, 0.5 g): (**a**) measuring point 2; (**b**) measuring point 3; (**c**) measuring point 4; (**d**) measuring point 5.