A theoretical model for a piezoelectric energy harvester with a tapered shape

This article investigates vibration rejection for a continuous smart structure using piezoelectric bimorph patches. Such a structure has inherent nonlinearities, such as hysteresis and creep, and the whole system may experience unexpected disturbances, uncertainties, and noise from external sources. Thus, it is very important to design the active control scheme carefully with adaptive filtering systems to deal with these conditions. An advanced adaptive filtering algorithm was developed based on the conventional least mean squares (LMS) method and sliding mode control for the active vibration rejection system. The sliding mode controller is applied to the standard LMS algorithm to overcome problems with misadjustment and excess error in an optimal manner. A numerical analysis and laboratory experiment show that the technique can significantly attenuate the vibration of the smart structure at different levels and broadband frequency spectra. In addition, unidentified impedance is chosen to change the distribution of the mass, and the robustness and the adaptivity of the proposed approach are verified. The experimental results show that the method can isolate impulse-type vibrations of at least 2.8 dB, even with the adjusted mass arrangement.

https://www.mdpi.com/2076-3417/7/7/750/pdf

Enhanced Adaptive Filtering Algorithm Based on Sliding Mode Control for Active Vibration Rejection of Smart Beam Structures

In this study, we derived an electroelastic solution of functionally graded piezoelectric beams with bimodular effect under the combined action of uniformly distributed loads, concentrated loads, a...

An electroelastic solution for functionally graded piezoelectric material beams with different moduli in tension and compression

The purpose of this article is to investigate the active control behavior and stress analysis of functionally graded piezoelectric material circular hollow cylinder and disk under electro-thermo-mechanical loading. Also, this research presents a new compact formula for analysis of cylinder and disk that could be useful for engineers and designers to get insight into behavioral change of structures by geometry. The exact solutions of the functionally graded piezoelectric material structures could be found based on Lame’s solution. For a radially polarized cylinder and disk with continuously graded properties, it is assumed that material properties are varied by a power-law function, and inner surface and outer surface of these structures are considered to be sensor and actuator, respectively. Based on the exact solution, extensive numerical analyses are carried out to provide an insight into the effect of non-homogeneity constant and control factor on electro-thermo-mechanical behaviors and active control ...

Stress and active control analysis of functionally graded piezoelectric material cylinder and disk under electro-thermo-mechanical loading

An analytical model of the dynamic properties is established for a piezoelectric structure under impact load, without considering noise and perturbations in this paper. Based on the general theory of piezo-elasticity and impact mechanics, the theoretical solutions of the mechanical and electrical fields of the smart structure are obtained with the standing and traveling wave methods, respectively. The comparisons between the two methods have shown that the standing wave method is better for studying long-time response after an impact load. In addition, good agreements are found between the theoretical and the numerical results. To simulate the impact load, both triangle and step pulse loads are used and comparisons are given. Furthermore, the influence of several parameters is discussed so as to provide some advices for practical use. It can be seen that the proposed analytical model would benefit, to some extent, the design and application (especially the airport runway) of the related smart devices by taking into account their impact load performance.

Analysis of Dynamic Properties of Piezoelectric Structure under Impact Load

Most of the previous investigations on the static performances of piezoelectric bimorph cantilevers are based on the elementary theory of piezo-elasticity. In fact, one fundamental problem has not ...

Ruixiang Yao

Papers

Solution modification of a piezoelectric bimorph cantilever under loads