## 4 Experimental Verification
### Dataset  
Along the Y direction marked in Figure 8, the shaker table presents a base excitation. The experimental parameters are shown in Table 2. The Agilent VXI Plus&Play system is acceleration signal acquisition equipment. The sensitivity of the acceleration sensor is 100.4 mv/g, and the type is PCB 333B32. In the experimental system of the slender aluminum beam, the first five acceleration sensors measure the acceleration response signals, including white noise and non-white noise excitations, and the last sensor measures the excitation signals (Figure 8). In the experimental system of the aluminum rudder space structure, the first acceleration sensor measures the white noise and non-white noise excitation signals, and the second and third sensors measure the acceleration response signals (Figure 9).  
Figure 6: Modal frequency of the first beam.  
Figure 7: Modal shapes of the first beam.  
In general, the white noise excitation spectrum refers to the excitation spectrum of PSD uniformly distributed throughout the frequency domain, and its PSD function is a straight line. The non-uniform excitation spectrum refers to the excitation spectrum of the PSD function is not a straight line, it is also called the non-white noise excitation spectrum. Within a given frequency range, blue noise, pink noise, purple noise, and brown noise  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{2}{c}{**Physical Parameters**} & \multicolumn{4}{c}{**Experimental Parameters**} \\ \hline \multirow{2}{*}{**Elastic Modulus (Pa)**} & **Mass Density** & \multirow{2}{*}{**Spectral Lines**} & **Analysis Frequency** & **Sampling** & **Sampling** & **Sampling** \\  & **(kg/m3)** & & **Band (Hz)** & **Frequency (Hz)** & **Length (s)** & **Test Time (s)** \\ \hline \(7.1\times 10^{10}\) & 2770 & 800 & 1000 & 2560 & 0.8 & 400 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Experimental parameters.  
Figure 8: Experimental system of the slender aluminum beam: (**a**) structural diagram; (**b**) experimental diagram.  
Figure 9: Experimental system of the aluminum rudder surface: (**a**) structural diagram; (**b**) experimental diagram.  
(four typical non-white noises) refer to the increase and decrease in PSD by 3 dB and 6 dB per octave with the increase in frequency. The beam and rudder surface are widely used in the aerospace field and can be used to study the flight state of the aircraft, and the actual situation is non-white noise excitation [51]. In addition, the measurement of boundary layer pressure fluctuation in hypersonic wind tunnels shows that the boundary pressure fluctuation has a non-flat spectrum and should be regarded as non-white noise [52]. Therefore, three excitation spectra, including white and non-white noise excitations, are applied to simulate the ambient excitation in this paper. Where the excitation spectrum 1 is white noise excitation, the excitation spectrum 2 is a mixed spectrum composed of blue, narrow-band white, and pink noises. Similarly, excitation spectrum 3 is a mixed spectrum composed of purple, narrow-band white, and brown noises (Figure 10).  
As mentioned earlier, according to the dataset construction process (Figure 2), the response signals measured under the above three spectrum excitations (Figure 10) are processed, and the dataset is constructed. The dataset obtained by processing the acceleration response signals of the beam (Figure 8b) excited by excitation spectrum 1 are regarded as dataset 1, and the dataset obtained by processing the acceleration response signals of the beam excited by excitation spectrum2 and excitation spectrum 3 are regarded as dataset 2. Similarly, the dataset obtained by processing the acceleration response signals of the rudder surface (Figure 9b) excited by excitation spectrum 1 are regarded as dataset 3, and the dataset obtained by processing the acceleration response signals of the rudder surface excited by excitation spectrum2 and excitation spectrum 3 are regarded as dataset 4. The training set and test set proportion are 8:2.