Study On Acquisition Of The Bridge Vibration Energy And The Structure Design Of The Piezoelectric Transducer Under Vehicle Action

As a new type of energy,vibration has the characteristics of large energy density and wide range of existence,which makes the acquisition of vibration energy has a wide range of prospects for application in the field of electronic equipment,communication equipment and other micro power supply fields.The bridge exists widely,which makes the bridge have a lot of vibration energy under the action of vehicle.Due to the complex vibration mode of bridge,the vibration energy generated by the bridge is not fully utilized.In this paper,a method of collecting bridge vibration energy and converting it into electrical energy is proposed based on piezoelectric cantilever beam,which provides a way to make full use of the vibrational energy of bridge.The vehicle flow condition,vehicle kinematics model,kinematics equation and related theory of piezoelectric cantilever are studied.The classical analytical theory of four simplified models of vehicle bridge coupled vibration is compared and studied.It is found that the theory of uniform moving spring mass interaction is closer to the actual situation.After comparing the vehicle flow at different time periods,two typical periods of the vehicle flow were found.Based on the theory of uniform moving spring mass action,kinematics model and kinematics equation of the typical vehicle are established.The vibration equation,equivalent stiffness and optimum adhesive position of piezoelectric cantilever beam are analyzed.A variety of piezoelectric materials are compared,and the characteristics of piezoelectric materials are recognized.The influence laws of the vehicle speed,axle load and driving lane on amplitude frequency characteristics of the bridge are studied.Based on the Ansys software simulation,the displacement time process data of the bridge under different axle load,different speed and different lane conditions are obtained.Based on the Matlab software,the amplitude frequency characteristics of the bridge vibration are obtained by processing the displacement time process data.The study shows that the bridge vibration belongs to the category of low frequency vibration,and the driving lanes are also an important factor.The dynamic response law of the bridge span is studied.It is found that the amplitude of the bridge span is the largest in the bridge fundamental frequency.And the amplitude frequency characteristics of the bridge vibration under various working conditions are compared,and the more close to the actual vehicle condition is determined.The influence laws of the counterweight,cantilever length,thickness of piezoelectric ceramic plate,thickness of substrate and width of cantilever beam on the mode shapes of piezoelectric cantilever are studied.Based on the Abaqus software simulation,the modal vibration mode of the piezoelectric cantilever beam is obtained.And we realize the influence law of the height of the lead block,the length of the cantilever beam,the thickness of the piezoelectric ceramic plate,the thickness of the substrate and the width of the cantilever beam on the modal vibration mode of the piezoelectric cantilever beam.It is found that the vibration frequency and amplitude of the cantilever beam in the optimum size are basically coupled with the vibration of the bridge,that is,to generate resonance,which will improve the efficiency of the electric energy conversion.And the strength of the cantilever beam also meets the actual requirements.