| dc.description.abstract | In this study, the motion equations of Piezoelectric - Multiple Tuned Mass Dampers (Piezo-MTMDs) combined with double-layered piezoelectric cantilever beams and rigid rods were derived, and experimental verification was carried out after optimizing the design parameters. First, the piezoelectric constitutive equation was used in the form of an Euler–Bernoulli beam to derive the mechanics and circuit motion equations of the double-layer piezoelectric layer in series. Then, the finite elements concept was used to combine the piezoelectric cantilever beam with the regular rod. Each was regarded as an element, and a multi-degree-of-freedom motion equation in the form of a matrix composed of different sections was deduced. An external mass block and a resistor were added to obtain a complete mechanical and circuit motion equation. Here, the mathematical model in the form of a multi-degree-of-freedom matrix was called the Full model. Then, the polynomial shape function of the rigid rod end displacement degree of freedom was substituted into the piezoelectric motion equation to obtain the Simplify model with a single degree of freedom. By rewriting the motion equations of the two mathematical models into state spaces, their systems could be analyzed separately, frequency response functions could be drawn, and it was confirmed that the Simplify model could replace the Full model as the mathematical model for subsequent simulations. Among them, the piezo-damping ratio was used as an indicator to judge the power generation efficiency. Therefore, a sensitivity analysis was performed on the size of the external mass, the length of the rigid rod, the total thickness of the piezoelectric cantilever beam and the thickness ratio, and the thickness ratio and resistance. From the analysis results, it was seen that the size of the external mass block, the size and thickness ratio of the piezoelectric cantilever beam, and the rigid rod had different effects on the piezo-damping ratio. The material size needed to be selected based on actual requirements. Through previous research conducted by our team, we knew that the piezo-damping ratio was affected by the axial load of geometric stiffness. In order to improve its value, the Piezo-TMD was erected in the form of an inverted cantilever beam, which could transform the influence of the axial load on the piezo-damping ratio into a positive effect. In order to increase the mass ratio to achieve a better vibration reduction effect and energy harvest, multiple Piezo-TMDs were configured to form Piezo-MTMDs, which could increase the mass ratio and reduce the demand for the optimal damping ratio to facilitate piezoelectric materials used. Then the motion equations of adding Piezo-MTMDs to the aeroelastic model were deduced, the model basis of a single Piezo-TMD was fixed, the Direct Search method was used for optimal design, and the Piezo-TMD external mass block and resistor corresponding to the two optimal design methods were found when the structure velocity frequency response function H2-norm value was minimum and the mean power value was maximum. After analysis, the optimal parameters designed to maximize the mean power could capture more energy under similar vibration reduction effects, so subsequent analysis used this parameter. After plotting the frequency response function and conducting dynamic analysis based on the design wind force, it was seen that Piezo-MTMDs had good power generation effects while reducing vibration. Finally, 6 Piezo-TMD specimens were produced, and each of them was systematically identified to find out the piezoelectric material parameters that fit the actual situation. After re-optimizing the design of the external mass block and resistor of each Piezo-TMD specimen, the wind tunnel experiments were conducted on an aeroelastic model equipped with Piezo-MTMDs. It was evident from the experiment results that Piezo-MTMDs had a significant impact on reducing vibrations in the aeroelastic model, while simultaneously producing electrical energy to promote sustainable energy utilization. | en_US |