Study On Response Characteristics Of Bistable Vibration Energy Harvesting System Based On Potential Energy Function

With the low power of microelectronic devices,piezoelectric vibration energy harvesting systems have received extensive attention as their self-powered power supplies.The piezoelectric vibration energy harvesting system is based on the principle of piezoelectric effect.When the structure is excited by the environment,the piezoelectric sheet is deformed to form collectable electric energy.Among them,the bistable piezoelectric vibration energy harvesting system has a wide low-frequency response frequency band and the system can enter the high-energy orbit to generate a large periodic motion response under certain excitation.Therefore,the system is considered as a practical and efficient energy acquisition system.However,the response characteristics of the system are affected by many factors.However,the response characteristics of the system are affected by many factors.How to broaden the output response of the system under low-amplitude and low-frequency excitation and how to enter and maintain the high-energy orbit is the key to whether the system can enter the practical stage.In this paper,based on the energy point of view,based on Euler-Bernoulli beam theory,piezoelectric material constitutive equation,magnetic dipole theory and Lagrangian equation,the dynamics of bistable piezoelectric vibration energy harvesting system is constructed.The model mainly uses numerical simulation analysis method to analyze the influence of system potential energy on system output performance,and proposes two structural methods to improve system output.The work of this paper mainly includes the following aspects:1.The current research status of piezoelectric energy harvesting system at home and abroad is reviewed,and the research contents of this paper are briefly summarized.2.According to the existing research theory,the distributed parameter model of the traditional bistable system is established.Then,the influence of the system parameters of the non-linear force-supplying magnets(the distance between the magnets and the volume of the magnets)on the potential energy and output performance of the bistable system is analyzed by numerical simulation.3.Adjusting the non-linear force factor of the system by adding external adjusting magnetic blocks;establishing its mathematical model,analyzing the influence of different placement schemes of adjusting magnetic blocks on the shape of the potential energy function of the system,and on the output performance of each system under different excitation amplitudes and frequencies;the analysis results show that the structure has the effect of improving the output performance.4.A bistable system with variable potential energy is constructed by connecting an elastic connecting device with an external magnetic block;the elastic device's flexibility is utilized to make the system self-adaptively change its structural potential energy under forced vibration;a mathematical model is established to analyze the effect of the elastic connecting device on the system under different excitation conditions;the analysis results show that the elastic connecting mechanism can improve the output performance of the system.Finally,this paper summarizes the relevant laws and provides theoretical reference for the practical application of bistable systems.