Piezoelectric Composite Material Damping Mechanism And Active Controlling Of The Cantilever Beam

Piezoelectric composite is mainly made of the reinforcing phase and the matrixphase composite, which is a new kind of functional material. These new dampingmaterials have been widely used in transportation, aerospace and marine, construction,machinery, etc. The main route of piezoelectric damping composite is mechanical vibrationenergyâ†'electricity energyâ†'thermal energy. Using energy fiber optic temperature sensorto generate the energy made by piezoelectric composites and it has been rarely reported thatpiezoelectric composite damping mechanism; under the PID active control, the vibrationresponse of piezoelectric cantilever beam.As the FBG is fragile and people generally use metal to encapsulation. Thecoefficient of thermal expansion of the metal is (10-20)*10-6/℃, the strength andthe stiffness are high, vibration is not easy deformation, it is suitable for packagingmaterials. It not only improves the sensitivity of fiber gratings and fiber gratingplayed a very good protection. The best placement method is to the direction of thefiber grating with cantilever vibration measurements. The result of FBG temperaturelinear correlation calibration was R1=0.9985and R2=0.99807. The linearcorrelation is well, which can be used as a temperature sensing element in theexperiment. FBG temperature response of the linear fit is good. FBG package aftersensitization with more than bare FBG (temperature coefficient of0.0132) toenhance the sensitivity of high amplitude coefficient is3.04times the bare FBGsensitivity coefficients, indicating the package to achieve a better sensitizing effect.Using the spectrometer to measure the qualitative results of heat energyvibrating piezoelectric cantilever beam, after a period of sustained vibration, thecenter wavelength increases, temperature of the piezoelectric damping materials;Using demodulator can be quantitatively calculate the vibration of a piezoelectriccantilever composite heat energy, the temperature within the measurement time isabout0.62℃. Using DMA and DASP software test method to compare the dampingperformance of the different proportions of piezoelectric composites.Instantaneous signal and alternating signals are as driven signals, using PIDcontrol, change control coefficient P ’s size, The stopping time of impact force underinstantaneous signal with the piezoelectric ceramic content increases, the stopping time is reduced; after applying active control, the stopping is shorter than the activecontrol is not applied. The alternating signal is applied to force the cantilever beam,the control coefficient is P=5, the driving effect of the ceramic sheet is located in acantilever position A, B, C, the driving control of the ceramic sheet C, the cantilevervibration amplitude decreases up, the effect of C under controlling is at best. Theeffect of two ceramics is better than three ceramics, the best control position is B+C.The average time for the active control of using Drive-1and Drive-2are4.29s and4.812s, the control time of Drive-1driven piece is shorter than Drive-2, indicatingthat for the same cantilever and control coefficient, a thicker slice has a better effectof active control.