Structure Design And Multi-physical Field Coupling Characteristics Analysis Of 3-D Braided Piezoelectric Composite Vibration Energy Harvesting Device

With the wide application of wireless sensor networks and internet of things technology,piezoelectric vibration energy harvesting technology has received more and more attention and research.This technology has the advantages of simple structure,light weight,low pollution,and easy to be used many times,which is widely used in the fields of environmental monitoring,health monitoring,structural monitoring,and smart home.In the piezoelectric vibration energy harvesting device,piezoelectric ceramic material is the main structural material,but piezoelectric ceramic is an inorganic material with poor quality factor and low strength,which largely affects its application in the actual structure,so the selection of a material with excellent performance to form a monolithic structure with piezoelectric ceramic is of great significance to the development of intelligent structures.Because to their superior designability and interlayer performance,3-D braided composite materials have found widespread application in industries as diverse as aircraft,medicine,sports,and marine engineering.This thesis combines 3-D braided technology with piezoelectric vibration energy harvesting technology to establish a3-D braided piezoelectric composite vibration energy harvesting device(3-D BPCVEHD)to improve the energy harvesting device’s mechanical performance and output response.The main work of this article is as follows:First,according to the 3-D four-step braided process,the prefabricated model of the 3-D braided composite is established by the 3-D modeling software UG.On this basis,the periodic representative volume cell model and finite element model of the3-D braided composite are obtained.Analysis of the finite element model of 3-D braided composite with ABAQUS software the elastic performance parameters,thermo-dynamic performance parameters and electrical performance parameters of the3-D braided composites are obtained.Secondly,a novel 3-D BPCVEHD is established by combining carbon fiber and piezoelectric ceramic matrix through 3-D braided technology.The dynamic model under forced vibration is obtained,and vibration mode and output response are analyzed.Finally,we investigate the effects of excitation frequency,load resistance,and external excitation acceleration on the output response and the low-frequency frequency domain response of a 3-D BPCVEHD with varying volume fractions.Finally,a 3-D BPCVEHD with a symmetrical bi-piezoelectric structure and a 3-D braided elastic layer in the middle of the upper and lower piezoelectric layers is established.The governing equations of 3-D BPCVEHD under force-electrical-thermal coupling are derived using Newtonian mechanics theory.The output response of the3-D BPCVEHD affected by the excitation frequency,load resistance and external excitation at different temperatures are studied,and its frequency domain response analysis at different temperatures is carried out.