## 4 Experimental Validation  
In order to validate the rightness of the mathematical model and simulation study, the experiment model machine is fabricated, and the experiment testing platform is built into this research. Figure 12 shows the experimental prototype of CTEHS. The combined beam is made of beryllium bronze material and is machined in one piece. The right end of the beam is clipped and fastened to the pedestal with a fixture, and the left end is glued with a magnet. The top and bottom surfaces of the PVDF piezoelectric film are welded with wires and packaged with insulating tape, and then the treated piezoelectric film is attached to the combined beam with silicone sealant. Two magnets are bonded symmetrically on the left inner wall of the pedestal. The pedestal is provided with several guide rails and chutes, which can be used to regulate the spacing among these magnets. Figure 13 shows the experiment testing platform of the system. When the experiment is conducted, the experiment model machine is first fixed to the shaker (LT-50 ST) by screws, then the vibration parameters are configured by the control software, and the vibration signals are transmitted to the shaker controller (VT-9008), then the vibration signals are magnified by the power amplifier (VSA-L1000A) and passed to the shaker to make the experiment model machine on the shaker vibrate. The end velocity and displacement of the combined beam are gauged by a laser vibrometer (LV-S01) and recorded using a vibration analyzer (CoCo-80X). The response voltage of the system is displayed and collected by a digital oscilloscope (DSOX3024T). To verify the effect of different end magnet masses \(M_{\mathrm{e}}\) on the system's response characteristics, set the vibration frequency \(f=10\) Hz, the vibration acceleration \(A=10\) m/s\({}^{2}\), and take the magnet distances \(d_{\mathrm{h}}=12\) mm and \(d_{\mathrm{v}}=15\) mm  
in Figure 14b, the system can surmount the obstacle of the potential barrier and realize a large-amplitude oscillation between wells. The system's vibration displacement amplitude achieves 28 mm, and the RMS voltage reaches 46.38 V. In addition, it can be seen from Figure 14 that the system's vibration displacement and voltage are asymmetric about the origin, which indicates that the motion of the system under the gravity of the magnet is asymmetric. This is consistent with the results of the simulation analysis. To verify the effect of different initial vibration points \(u_{0}\) on the system's response characteristics, take the magnet distances \(d_{\text{h}}=12\) mm and \(d_{\text{v}}=16\) mm, the end magnet mass \(M_{\text{e}}=10\) g, set the vibration frequency \(f=10\) Hz and the vibration acceleration \(A=9\) m/s\({}^{2}\). Figure 15 shows the phase graph, time course graph of the experiment when \(u_{0}\) is \(-14\) mm and 12 mm, respectively. When \(u_{0}=-14\) mm, as shown in Figure 15a, the system is unable to get rid of the constraints of the deeper potential well and can only do intra-well periodic oscillations. At this time, the system's vibration displacement amplitude is just 2.1 mm and the RMS voltage is just 3.41 V. As shown in Figure 15b, when \(u_{0}=12\) mm, the system is able to readily pass the lower potential barrier and perform inter-well periodic oscillation. The system's vibration displacement amplitude is increased to 32 mm, and the RMS voltage achieves 49.66 V.  
The above experiment results have a fine consistency with the theoretical calculations qualitatively, but there are some deviations in quantitative terms. The main sources of these deviations are: (1) In the experimental prototype, there is a slight error in the size of the fabricated magnet and the combined beam with the simulation.