Research On Vibration Control Of Thin-walled Vehicle Components Based On Shunted Piezoelectric Technology

During the operation of the subway,the vibration of the vehicle is caused by the force between the wheel and the rail,the friction between the air and the surface of the train,which causes the vibration of the thin-walled vehicle components.In the design and manufacture of existing subway trains,the primary and secondary suspension,lateral and longitudinal damper,etc.are commonly used to control vehicle vibration as a whole,and they often control vibrations in a wide range of frequencies and cannot be aimed at the certain modal vibration of thin-walled components of the vehicle.Therefore,a method based on shunted piezoelectric is proposed to control the vibration of partial thin-walled components of the vehicle.This paper takes the thin-walled components of subway vehicles as the research object,establishes its structural physical scale model—thin plate,and uses the positive piezoelectric effect of piezoelectric materials and passively control the first few modes of the structure with shunt circuits.In this paper,the research on shunted piezoelectric passive vibration control is carried out from the following aspects:1.The mathematical model of the plate and piezoelectric patch is established.According to the classic laminate theory,the out-of-plane bending response of the shunted piezoelectric patch with the plate is derived,and the constitutive equations are established based on the characteristics of the piezoelectric materials and the plate.Based on the established electromechanical system,the flexural vibration motion equation of the plate and the piezoelectric patch with the shunt circuits is established.As far as the system of the plate and piezoelectric patch,its lateral displacement can be separated in time and space variables.According to the space variables,the mass,stiffness,damping and electromechanical coupling coefficient of the piezoelectric patch and the plate in each mode can be obtained.In this way,the state equation in the time domain is obtained and converted into the frequency domain to obtain the natural frequencies and natural modes of the system.2.The design of the shunt circuit.In the process of the plate vibration control based on shunted piezoelectric,the piezoelectric patch converts the mechanical energy of the plate vibration into electrical energy,and the function of the shunt circuits is to consume this part of the electrical energy.Here,the shunt circuits are divided into a single mode control shunt,a multimodal control shunt,and a negative capacitance shunt.The optimal value of each circuit parameter is obtained through H₂ optimization standards,and finally the system bending kinetic energy power spectrum density under each circuit is obtained.The results show that the shunted piezoelectric is equivalent to a damping effect,which has a certain inhibitory effect on the vibration of the plate.As for the negative capacitance shunt,the negative capacitance improves the damping ability by increasing the electromechanical coupling coefficient value of the system,and the control frequency band is wider,but it also involves the problem of system stability.3.The influence of position,size and number of piezoelectric patch on vibration control of the plate is analyzed.The shunted piezoelectric can reduce the vibration of the plate to a certain extent,but also change the inherent properties of the system,and when a single piezoelectric patch is used to control the multiple modes of the structure,the coupling phenomenon between complex circuits will also weaken the vibration control.So multiple piezoelectric patches are used to control multiple modes of the structure,and it has a good vibration control effect.In summary,through building a system model between the piezoelectric patch and the plate,a single mode control shunt,a multimodal control shunt and a negative capacitance shunt are designed for the plate vibration control,and the parameters of circuits are optimized through optimization standards.In low order modal control,because the required inductance value is relatively large,it needs to simulate the inductance,and verifies the correctness of the analog circuits through Multisim software simulation.Finally,the kinetic energy power spectral density of the plate and piezoelectric patch system under the single mode circuit,the multimodal circuit and the negative capacitance circuit was studied and calculated.It shows that shunted piezoelectric patch for the vibration control of the plate has a good effect,and the advantages and disadvantages of each circuit are analyzed.In addition,the influence of the position,parameters and number of piezoelectric patch on vibration control is studied.