Studies On0-3Type PZT/Epoxy Piezoelectric Composite Performance Prediction And Applications

Piezoelectric composites consist of piezoelectric ceramic phase and matrix, andpossess both of the material characteristics of piezoelectric ceramics and matrix. The0-3type piezoelectric composites are prepared by blending piezoelectric ceramicparticles and matrix phase directly, since the0-3type piezoelectric composites havesimple formation process and can be formed into different shapes. The0-3typepiezoelectric composites have been widely applied to the electroelastic energytransformation. As the material has the capability of transforming the mechanical energyinto electric energy, piezoelectric material can be applied to structural vibration controland piezoelectric energy harvesting. However, the researches of the inhomogeneous0-3type piezoelectric composites on structural vibration control and piezoelectric energyharvesting are not many. The research reports are only focused on experimental method,and lack of theoretical analysis. In this thesis, firstly, the material constants of the0-3type PZT/Epoxy piezoelectric composites were predicted by mathematical theory. Then,the applications of the0-3type PZT/Epoxy piezoelectric composites on vibrationreduction and energy harvesting were studied by numerical simulation, according to thecalculation results of the material constants of the0-3type piezoelectric composites.The experimental tests were also carried out to verify the numerical prediction results.A numerical prediction method on material constants of the0-3type piezoelectriccomposites is necessary before the materials are applied. At present, many numericalmethods have been given to predict the material constants of the0-3type piezoelectriccomposites. In order to gain a convenient and efficient prediction method, the finiteelement numerical method based on double scale homogenization theory was used topredict the material constants of the0-3type piezoelectric composites in this thesis.Compared with the results of direct finite element method, Mori-Tanaka method andanalytic method, the numerical results of the method used in this thesis are provedaccurate, convenience and lower computational cost. The finite element numericalmethod based on double scale homogenization theory was also demonstrated reliablethrough the material performance tests on the PZT/Epoxy composites.The0-3type piezoelectric composites including conductive phase can transformthe external mechanical vibration energy into joule heat by piezoelectric ceramic phaseand material volume resistance. This mechanical energy dissipation can be defined aspiezoelectric damping. For analyzing the piezoelectric damping of0-3typepiezoelectric composites, the electric piezoelectric passive shunt theory and the resultsof the finite element numerical method based on double scale homogenization theorywere used to establish calculation method. The dynamic mechanical analysis testingwas used to study the piezoelectric damping of the0-3type piezoelectric composites. by the numerical method and the dynamic mechanical analysis testing. It is found thatwhen the content of carbon black approaches the conductive percolation threshold，thepiezoelectric damping of the piezoelectric/carbon black/epoxy piezoelectric compositereaches maximumBased on the research results of the damping of0-3type piezoelectric composites,a new type of laminated carbon-fiber composite was developed by doping thepiezoelectric ceramic particles into the layers of laminated carbon fiber composite inorder to reduce the underwater vibration and noise of laminated carbon-fiber composite.In this thesis, fluid-structure coupled finite element numerical method was used tocalculate the underwater displacement response of carbon-fiber composite laminatedplate with PZT particle doped between layers. The sound radiation and sound pressuredistribution in underwater sound field were calculated by acoustic boundary elementmethod. It is found that the carbon-fiber laminated composite plate with PZT particlesdoped between layers has lower vibration and noise than the pure carbon-fiberlaminated composite plate in according to the results of numerical simulation. The testplatform of underwater acoustic radiation was also set up to measure the underwatervibration sound pressure of the modified carbon-fiber laminated composite plate.The piezoelectric energy harvesting performance of the0-3PZT/Epoxypiezoelectric composite was studied by the statics method and the dynamic finiteelement method, based on a cantilever-beam piezoelectric vibrator model, Thepiezoelectric energy harvesting performance of the cantilever-beam PZT/Epoxypiezoelectric composite vibrators with different material contents, geometric shapesand modal frequency were analyzed by numerical method, and some tests were alsoused to verify the numerical results. The elements which influence the piezoelectricenergy harvesting performance of the cantilever-beam PZT/Epoxy piezoelectriccomposite vibrators are summarized. These analysis results can help to improve theefficiency of the PZT/Epoxy piezoelectric composite vibrators.In this thesis, the researches on the0-3type piezoelectric composites enrich thematerial constant prediction method on the materials as the0-3type piezoelectriccomposites, and also provide theoretical basis for the applications on structuralvibration control and piezoelectric energy harvesting...