Study Of D₁₅ Mode Piezoelectric Energy Harvesting Under Periodic Strong Impact Vibration

Abundant vibration was generated on railway tracks and tunnel road,cars and ships movement.And most of those vibration have characteristics as high accelerate amplitude and short impact even milliseconds.Vibration acceleration up to several tens of g,and usually piezoelectric energy harvester(PEH)collected vibration energy amplitude of not more than 5g.In order to harvesting those kind of short impact vibration,the d15 shear mode piezoelectric energy harvester,which has effective energy harvesting ability and more impact resistance and no temperature drift,and a kind of circuit with slow energy storage function are studied in this paper.The main research content are as follows.Based on the piezoelectric equation and the characteristics of PZT piezoelectric ceramics,the finite element mode of PEH and the d-type equivalent circuit of electromechanical are established.In order to harvesting those kind of short impact vibration,we designed three kinds of PEH: vertical PEH,cantilever PEH and L-type PEH.The performance of these PEH is analyzed by using ANSYS finite element software and the relationship between the output voltage and the excitation frequency and the relationship between the output characteristic and the load resistance is obtained.The results show that the output voltage of the vertical type PEH has a good linear relationship with the excitation amplitude.The energy release effect of the cantilever type PEH is the best,and the output power of the L-type PEH is the highest at 33.64?W.In order to harvest the shock impact energy by releasing the short impact,a kind of energy storage circuit which can collect the impact energy efficiently in the literature was analyzed by using Multisim software.This energy storage circuit also was connected to the L-type PEH.The experiment successfully lit a LED light and the voltage of the energy storage capacitor increased with the repeated impact.The simulation and experimental results show that the d15 shear-mode PEH has a good linearity in the vibration.When impact acceleration is high,the PEH structure has high fatigue resistance,no performance damage and stability.