## 6 Experimental Validation  
To carry out the vibro-acoustic experiment of the 2D ABH coupling system, a 2D ABH rectangular plate and an acoustic cavity shell were manufactured. The geometric parameters of the ABH plate and the shell were the same as the model established in Section 4, and the material was 1060 AL. Figure 11 shows the physical image of the 2D ABH plate fixed on the fixture. The contact area between the ABH plate and the shell was pasted with acrylic double-sided tape to connect them and prevent sound leakage.  
The complete experimental platform of the vibro-acoustic measurement of the 2D ABH coupling system is shown in Figure 12. Both the shaker and the fixture are fixed on the blue platform below. The m + p VibPilot generates a sinusoidal sweep signal and drives the shaker to act on the 2D ABH plate. The acoustic sensor, acceleration sensors, and force  
Figure 11: Physical image of the 2D ABH rectangular plate.  
Figure 10: Acoustic modal participation factor and structural modal participation factor of the damping ABH coupling system and the uniform thickness plate-cavity coupling system: (**a**) acoustic modal participation factor at 3701 Hz; (**b**) acoustic modal participation factor at 4501 Hz; (**c**) structural modal participation factor at 3701 Hz; (**d**) structural modal participation factor at 4501 Hz.  
sensor are all connected to m + p VibPilot. The amplitude of the excitation force is 10 N, and the frequency is 0-5 kHz. The position of the excitation force is the centre of the ABH plate (based on the coordinate system in Figure 8, the coordinate of the point of excitation force is (0, 0, 400)). The end of the shaker is connected with a force sensor and a magnetic base, and the magnetic base is pasted on the surface of the ABH plate with 502 glue. An acoustic sensor is placed inside the acoustic cavity. The acoustic sensor is located in the exact centre of the acoustic cavity and its position coordinate is (0, 0, 199). The surface of the ABH plate is also pasted with two acceleration sensors to measure the vibration of the ABH plate. VibPilot can collect the time-domain signals measured by the sensors and send the signals to the laptop computer for data processing using SO Analyser software.  
The sound pressure spectrum at the monitoring point (0, 0, 199) was calculated by numerical simulation, and the sound pressure spectrum at the same position measured in the experiment was compared with the simulation result, as shown in Figure 13. It can be seen from Figure 13 that for the undamping ABH coupling system in the range of 0-5 kHz, most of the frequencies where the sound pressures of the numerical simulation results and the experimental measurement results appeared as peaks were in good agreement, and the peak amplitude deviation of the sound pressure of these two results was small. Therefore, the accuracy of the FEM vibro-acoustic models of the 2D ABH coupling systems established in this paper and the numerical simulation calculation were proven by experiments.  
Figure 12: Experimental platform of vibro-acoustic measurement of the 2D ABH coupling system.  
Figure 13: Comparison of the simulation results and experimental results of the sound pressure of the 2D ABH plate-cavity coupling system.