## 3 Simulation Results and Experimental Verification  
### Simulation Modeling  
To investigate the acoustic and vibration characteristics of the reinforced laminated panel, the reinforced laminated panel was modeled using SolidWorks 2021 3D modeling software. The constructed 3D model was imported as a STEP file into HyperMesh 2017 software for meshing, and the resulting 3D model and finite element model are shown in Figure 8.  
As shown in the figure, both the top and bottom panels and the C-shaped ribs are discretized using QUAD square elements with a mesh size of 10 mm, for a total of 2070 elements. The connection between the C-shaped ribs and the upper and lower plates is made using RBE3 elements, for a total of 3432 elements. The finite element model of the reinforced laminated panel consists of 5502 structural elements. The material properties of stainless steel and acrylic structural adhesive are given in Table 2.  
Import the established finite element model into the acoustic simulation software. Prior to acoustic preprocessing of the model, check the mass and quality of all nodes and  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Material** & **Density (kg\(\cdot\)m\({}^{3}\))** & **Young’s Modulus (MPa)** & **Poisson’s Ratio** \\ \hline Stainless & 7700 & 210,000 & 0.30 \\ Acrylic structural adhesive & 900 & 5000 & 0.41 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Material properties of the reinforced laminated panel.  
Figure 8: Finite element modeling: (**a**) 3D model; (**b**) finite element model.  
Figure 7: Frequency spectrum graph of radiated sound power level from the reinforced laminated panel.  
elements. Generate acoustic envelope surfaces. Set the material parameters and fluid properties for the respective structures. Simultaneously, establish coupling relationships between the structures and cavities. To simulate the experimental conditions, initially, utilize the force-time curve obtained from tapping the small plate with a small hammer. Convert it into a force-frequency curve using Fourier transform and import it into the software as a force excitation. Apply it to the corresponding structural mesh nodes for the experiment. To simulate the effect of ground reflection on the sound radiation, an automatic matching layer (AML) is applied to the fluid mesh surfaces outside the bottom surface of the lower cavity. The length of the lower cavity corresponds to the distance between the bottom surface of the panel and the ground during the experiment, approximately 700 mm. To simulate vibration behavior under free conditions, no constraints are applied. To be consistent with the experiment, 28 evenly distributed planar field point grids are placed approximately 500 mm above the panel for sampling. The total number of fluid elements is 27,005. The model is shown in Figure 9. Using the direct acoustic-structural coupling method, the frequency range for the solution is set between 1 and 2000 Hz, with a solution step of 1 Hz. The acoustic power at each node of the planar field point is computed and superimposed, followed by taking the average to obtain the overall acoustic power. Subsequently, the simulation results are compared against the experimental results.