A sandwich-type piezoelectric self-sensing passive vibration suppression structure and method

Abstract

The present invention discloses a sandwich-type piezoelectric self-sensing passive vibration suppression structure and method. The sandwich-type piezoelectric self-sensing passive vibration suppression structure includes a piezoelectric body, a fixing block, a pre-tightening bolt and a passive control circuit. The object of vibration suppression is a cantilever beam, which is a cylinder or a regular prism with a threaded blind hole at the center of one end face. The piezoelectric body includes N piezoelectric units, and each piezoelectric unit includes 4 two-zone piezoelectric ceramic sheets. The passive control circuit includes a self-sensing bridge circuit, a threshold comparator and a threshold switch. During operation, the passive control circuit switches the stiffness of the system through the closing and opening of the threshold switch. When the threshold switch is closed, the piezoelectric body is short-circuited to neutralize charges and consume energy. When the threshold switch is opened, it switches to a high-stiffness state with strong deformation resistance, reducing the vibration deformation. The present invention belongs to passive vibration control, and has the advantages of environmental protection, strong reliability, convenience, wide application range, etc.

Description

Technical Field

[0001] The present invention relates to the fields of piezoelectric sensing and mechanical vibration control, and particularly to a sandwich-type piezoelectric self-sensing passive vibration suppression structure and method. Background Art

[0002] In fields such as aerospace and wind turbines, vibrating bodies usually appear in the form of cantilever beams. For example, wind turbine blades, satellite solar panels, space structures, etc. It is particularly important to suppress the vibration of cantilever beam vibrating bodies. At present, the passive control technology has poor effects and low adaptability, and it is difficult to achieve reliable vibration suppression in practice; while active vibration suppression cannot achieve vibration suppression under some conditions where it is difficult to provide external energy for the system, and at the same time the system is complex and the stability is poor.

[0003] The present invention is a piezoelectric sandwich structure. By closing and disconnecting the threshold switch in the passive control circuit, the stiffness of the system is switched. When the threshold switch is closed, the piezoelectric body is short-circuited to neutralize charges and consume energy; when the threshold switch is disconnected, the system is in a high-stiffness state with strong resistance to deformation, reducing vibration deformation. The present invention belongs to passive vibration control, and has the advantages of environmental protection, strong reliability, convenience, wide application range, etc. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a sandwich-type piezoelectric self-sensing passive vibration suppression structure and method for the defects involved in the background art.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] A sandwich-type piezoelectric self-sensing passive vibration suppression structure, whose vibration suppression object is a cantilever beam. The cantilever beam is a cylinder or a regular prism with a threaded blind hole at the center of one end face. The sandwich-type piezoelectric self-sensing passive vibration suppression structure includes a piezoelectric body, a fixing block, a pre-tightening bolt, and a passive control circuit;

[0007] The piezoelectric body includes N piezoelectric units, where N is a natural integer greater than or equal to 1;

[0008] The piezoelectric unit includes 4 two-zone piezoelectric ceramic sheets; the two-zone piezoelectric ceramic sheets have the same shape as the cross-section of the cantilever beam, and a through-hole for the pre-tightening bolt to pass through is provided at the center, and is polarized along the thickness direction, and the polarization dividing line is a straight line passing through the center of the two-zone piezoelectric ceramic sheet;

[0009] The four two-zone piezoelectric ceramic sheets are stacked in sequence. The polarization dividing lines of the first and second two-zone piezoelectric ceramic sheets are coplanar, the polarization dividing lines of the third and fourth two-zone piezoelectric ceramic sheets are coplanar, and the polarization dividing lines of the second and third two-zone piezoelectric ceramic sheets are perpendicular to each other; the polarization directions of the two zones in the first two-zone piezoelectric ceramic sheet are the same, the polarization directions of the two zones in the second two-zone piezoelectric ceramic sheet are the same, and the polarization directions of the first and second two-zone piezoelectric ceramic sheets are opposite; the polarization directions of the two zones in the third two-zone piezoelectric ceramic sheet are opposite, the polarization directions of the two zones in the fourth two-zone piezoelectric ceramic sheet are opposite, and the polarization directions of the third and fourth two-zone piezoelectric ceramic sheets are opposite;

[0010] The upper end surface of the first two-zone piezoelectric ceramic sheet, the upper end surface of the third two-zone piezoelectric ceramic sheet, and the lower end surface of the fourth two-zone piezoelectric ceramic sheet are connected to each other to serve as the first connection point of the piezoelectric unit; the lower end surface of the first two-zone piezoelectric ceramic sheet and the upper end surface of the second two-zone piezoelectric ceramic sheet are connected to each other to serve as the second connection point of the piezoelectric unit, and the lower end surface of the third two-zone piezoelectric ceramic sheet and the upper end surface of the fourth two-zone piezoelectric ceramic sheet are connected to each other to serve as the third connection point of the piezoelectric unit;

[0011] The fixing block is a column with the same cross-sectional shape as that of the cantilever beam, and a through hole or counterbore for cooperating with the pre-tightening bolt is provided along its axis;

[0012] The pre-tightening bolt passes through the fixing block, N piezoelectric units in sequence and is threadedly connected to the threaded blind hole on the cantilever beam, clamping the N piezoelectric units between the fixing block and the cantilever beam;

[0013] The first connection points of the respective piezoelectric units are connected in series with each other to serve as the grounding interface of the piezoelectric module, the second connection points of the respective piezoelectric units are connected in series with each other to serve as the first signal interface of the piezoelectric module, and the third connection points of the respective piezoelectric units are connected in series with each other to serve as the second signal interface of the piezoelectric module;

[0014] The passive circuit includes a resistor R1, a resistor R2, a resistor Rc, a capacitor Cr, an N-type MOS transistor, an NPN-type bipolar transistor, a P-type MOS transistor, a PNP-type bipolar transistor, a first diode, and a second diode;

[0015] The grounding interface of the piezoelectric module is electrically connected to one end of the resistor R1 and one end of the resistor Rc respectively, and the first signal interface of the piezoelectric module is connected to the second signal interface of the piezoelectric module, one end of the capacitor Cr, the drain of the N-type MOS transistor, and the drain of the P-type MOS transistor respectively;

[0016] The other end of the resistor R1 is connected to one end of the resistor R2, the source of the N-type MOS transistor, and the source of the P-type MOS transistor respectively;

[0017] The other end of the capacitor Cr is respectively connected to the other end of the resistor R2, the collector of the NPN transistor, and the collector of the PNP transistor;

[0018] The emitter of the NPN transistor is connected to the gate of the P-type MOS transistor, and the base is connected to the negative electrode of the first diode;

[0019] The emitter of the PNP transistor is connected to the gate of the N-type MOS transistor, and the base is connected to the positive electrode of the second diode;

[0020] The positive electrode of the first diode is respectively connected to the other end of the resistor Rc and the negative electrode of the second diode;

[0021] Let the capacitance of the piezoelectric module be Cp, then R1 * Cp = R2 * Cr.

[0022] As a further optimized solution of the sandwich-type piezoelectric self-sensing passive vibration suppression structure of the present invention, N is taken as 2.

[0023] The present invention also discloses a vibration suppression method for the sandwich-type piezoelectric self-sensing passive vibration suppression structure, which includes the following processes:

[0024] Let the N-type MOS transistor be a negative threshold switch, the P-type MOS transistor be a positive threshold switch, the NPN transistor and the first diode form a positive threshold comparator, and the PNP transistor and the second diode form a negative threshold comparator. When the vibration suppression object is disturbed and vibrates, the piezoelectric sensor generates a sensing signal due to the positive piezoelectric effect caused by the deformation, and the sensing signal affects the components of the control module to perform the following periodic changes:

[0025] Step 1), when the vibration suppression object undergoes bending vibration, the piezoelectric body generates deformation and the positive piezoelectric effect occurs, a voltage difference appears at the electrical boundary of the piezoelectric body, and an electrical signal is generated at the first signal interface or the second signal interface;

[0026] Step 2), the passive control circuit separates the electrical signal generated by the piezoelectric body into a self-sensing signal for monitoring the electrical state and vibration state of the piezoelectric body and a control signal for controlling the electrical boundary conditions of the piezoelectric body through bridge balance;

[0027] Step 3), the self-sensing signal increases as the vibration deformation of the vibration suppression object increases. When its voltage reaches the preset positive threshold, the positive threshold comparator is turned on, the positive threshold switch is closed, and the control signal controls the electrical boundary conditions of the piezoelectric body to change to a short circuit, and the charge accumulated at the electrical boundary of the piezoelectric body is neutralized to dissipate electrical energy;

[0028] Step 4), when the vibration of the vibration suppression object in the positive direction reaches the maximum and then begins to decrease, the self-sensing signal also decreases accordingly. When its voltage drops below the preset positive threshold, the positive threshold comparator disconnects, the positive threshold switch disconnects, and the control signal controls the electrical boundary condition of the piezoelectric body to change to an open circuit. The stiffness of the entire structure increases, the ability to resist elastic deformation is strong, and the vibration displacement is reduced.

[0029] Step 5), the vibration deformation of the vibration suppression object continues to decrease, and the self-sensing signal also decreases accordingly. When its voltage drops below the preset negative threshold, the negative threshold comparator connects, the negative threshold switch closes, and the control signal controls the electrical boundary condition of the piezoelectric body to change to a short circuit. The charges accumulated at the electrical boundary of the piezoelectric body are neutralized to dissipate electrical energy, and the stiffness of the entire structure becomes smaller.

[0030] Step 6), when the vibration of the vibration suppression object in the negative direction reaches the maximum and then begins to decrease, the self-sensing signal increases accordingly. When its voltage rises above the preset negative threshold, the negative threshold comparator disconnects, the negative threshold switch disconnects, and the control signal controls the electrical boundary condition of the piezoelectric body to change to an open circuit. The stiffness of the entire structure increases, the ability to resist elastic deformation is strong, and the vibration displacement is reduced.

[0031] Compared with the prior art, the present invention adopts the above technical solutions and has the following technical effects:

[0032] 1. The present invention has a sandwich structure, and the strain energy is better conducted to the piezoelectric body, making the electromechanical conversion ability of the system strong, the stiffness difference between the open circuit and the short circuit of the system larger, and the vibration suppression effect better; it is a passive control technology without the need for external energy input to the system, and has great development prospects in fields such as spacecraft and aircraft, with advantages such as environmental protection, energy conservation, and wide application.

[0033] 2. The present invention utilizes the characteristics of high stiffness in the open circuit and charge neutralization in the short circuit, and switches the stiffness of the system by closing and disconnecting the threshold switch in the passive control circuit. When the threshold switch is closed, the piezoelectric body is short-circuited to neutralize the charge and consume energy; when the threshold switch is disconnected, the system is in a high-stiffness state, with strong ability to resist deformation, reducing the vibration deformation, which is convenient, efficient, and reliable.

[0034] 3. The present invention has a simple structure, strong functionality, meets the development requirements of lightweight, does not require external energy input to the system, and has strong application prospects. Description of the Drawings

[0035] Figure 1 is the structural schematic diagram of the present invention;

[0036] Figure 2 is the electrical signal schematic diagram of the piezoelectric body in the present invention;

[0037] Figure 3It is a schematic diagram of the passive control circuit in the present invention;

[0038] Figure 4 It is a schematic diagram of the self-sensing signal and the transient response of the vibration displacement in the present invention;

[0039] Figure 5 It is a schematic diagram of the switching of the electrical signals in the open-circuit and short-circuit states of the piezoelectric body in the present invention.

[0040] In the figure, 1 - the object to be vibration-suppressed, 2 - the piezoelectric body, 3 - the fixing block, 4 - the pre-tightening bolt. Specific embodiments

[0041] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings:

[0042] The present invention can be implemented in many different forms and should not be considered limited to the embodiments described herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. In the drawings, components are enlarged for clarity.

[0043] As Figure 1 shown, the present invention discloses a sandwich-type piezoelectric self-sensing passive vibration suppression structure, the object to be vibration-suppressed of which is a cantilever beam, and the cantilever beam is a cylinder or a regular prism with a threaded blind hole at the center of one end face. The sandwich-type piezoelectric self-sensing passive vibration suppression structure includes a piezoelectric body, a fixing block, a pre-tightening bolt, and a passive control circuit;

[0044] The piezoelectric body includes N piezoelectric units, and N is a natural integer greater than or equal to 1;

[0045] As Figure 2 shown, the piezoelectric unit includes 4 two-zone piezoelectric ceramic sheets; the shapes of the two-zone piezoelectric ceramic sheets are the same as the cross-sectional shape of the cantilever beam, and a through hole for the pre-tightening bolt to pass through is provided at the center, and it is polarized along the thickness direction, and the polarization dividing line is a straight line passing through the center of the two-zone piezoelectric ceramic sheet;

[0046] The 4 two-zone piezoelectric ceramic sheets are stacked in sequence. The polarization dividing lines of the first and second two-zone piezoelectric ceramic sheets are coplanar, the polarization dividing lines of the third and fourth two-zone piezoelectric ceramic sheets are coplanar, and the polarization dividing lines of the second and third two-zone piezoelectric ceramic sheets are perpendicular to each other; the polarization directions of the two zones in the first two-zone piezoelectric ceramic sheet are the same, the polarization directions of the two zones in the second two-zone piezoelectric ceramic sheet are the same, and the polarization directions of the first and second two-zone piezoelectric ceramic sheets are opposite; the polarization directions of the two zones in the third two-zone piezoelectric ceramic sheet are opposite, the polarization directions of the two zones in the fourth two-zone piezoelectric ceramic sheet are opposite, and the polarization directions of the third and fourth two-zone piezoelectric ceramic sheets are opposite;

[0047] The upper end surface of the first two-part piezoelectric ceramic sheet, the upper end surface of the third two-part piezoelectric ceramic sheet, and the lower end surface of the fourth two-part piezoelectric ceramic sheet are connected to each other to form the first connection point of the piezoelectric unit; the lower end surface of the first two-part piezoelectric ceramic sheet and the upper end surface of the second two-part piezoelectric ceramic sheet are connected to form the second connection point of the piezoelectric unit, and the lower end surface of the third two-part piezoelectric ceramic sheet and the upper end surface of the fourth two-part piezoelectric ceramic sheet are connected to form the third connection point of the piezoelectric unit;

[0048] The fixing block is a column with the same cross-sectional shape as that of the cantilever beam, and a through hole or counterbore for cooperating with the pre-tightening bolt is provided along its axis;

[0049] The pre-tightening bolt passes through the fixing block, N piezoelectric units in sequence and is threadedly connected to the threaded blind hole on the cantilever beam, clamping the N piezoelectric units between the fixing block and the cantilever beam;

[0050] The first connection points of the respective piezoelectric units are connected in series to form the grounding interface of the piezoelectric module, the second connection points of the respective piezoelectric units are connected in series to form the first signal interface of the piezoelectric module, and the third connection points of the respective piezoelectric units are connected in series to form the second signal interface of the piezoelectric module;

[0051] As Figure 3 shown, the passive circuit includes a resistor R1, a resistor R2, a resistor Rc, a capacitor Cr, an N-type MOS transistor, an NPN-type bipolar transistor, a P-type MOS transistor, a PNP-type bipolar transistor, a first diode, and a second diode;

[0052] The grounding interface of the piezoelectric module is electrically connected to one end of the resistor R1 and one end of the resistor Rc respectively, and the first signal interface of the piezoelectric module is connected to the second signal interface of the piezoelectric module, one end of the capacitor Cr, the drain of the N-type MOS transistor, and the drain of the P-type MOS transistor respectively;

[0053] The other end of the resistor R1 is connected to one end of the resistor R2, the source of the N-type MOS transistor, and the source of the P-type MOS transistor respectively;

[0054] The other end of the capacitor Cr is connected to the other end of the resistor R2, the collector of the NPN-type bipolar transistor, and the collector of the PNP-type bipolar transistor respectively;

[0055] The emitter of the NPN-type bipolar transistor is connected to the gate of the P-type MOS transistor, and the base is connected to the negative electrode of the first diode;

[0056] The emitter of the PNP-type bipolar transistor is connected to the gate of the N-type MOS transistor, and the base is connected to the positive electrode of the second diode;

[0057] The positive electrode of the first diode is respectively connected to the other end of the resistor Rc and the negative electrode of the second diode;

[0058] Let the capacitance of the piezoelectric module be Cp, then R1*Cp = R2*Cr. The piezoelectric body, resistor R1, resistor R2, and capacitor Cr form a self-sensing bridge circuit. R1*Cp = R2*Cr makes this capacitance-resistance type bridge satisfy the bridge balance condition.

[0059] As a further optimized scheme of the sandwich piezoelectric self-sensing passive vibration suppression structure of the present invention, N is taken as 2.

[0060] In the passive control circuit, the N-type MOS transistor serves as a negative threshold switch, the P-type MOS transistor serves as a positive threshold switch, the NPN triode and the first diode form a positive threshold comparator, and the PNP triode and the second diode form a negative threshold comparator; the positive threshold comparator is used to control the conduction of the positive threshold switch, the negative threshold comparator is used to control the conduction of the negative threshold switch, and the comparison thresholds of the positive threshold comparator and the negative threshold comparator are both adjusted by the resistance value of the resistor Rc.

[0061] As Figure 4 、 Figure 5 shown, the present invention also discloses a vibration suppression method for the sandwich piezoelectric self-sensing passive vibration suppression structure, including the following processes:

[0062] When the vibration suppression object is disturbed and vibrates, the piezoelectric sensor generates a sensing signal due to the piezoelectric effect caused by the deformation. The sensing signal affects the components of the control module to perform the following periodic changes:

[0063] Step 1), when the vibration suppression object undergoes bending vibration, the piezoelectric body generates deformation and the piezoelectric effect occurs, a voltage difference appears at the electrical boundary of the piezoelectric body, and an electrical signal is generated at the first signal interface or the second signal interface;

[0064] Step 2), the passive control circuit separates the electrical signal generated by the piezoelectric body into a self-sensing signal for monitoring the electrical state and vibration state of the piezoelectric body and a control signal for controlling the electrical boundary conditions of the piezoelectric body through bridge balance;

[0065] Step 3), the self-sensing signal increases as the vibration deformation of the vibration suppression object increases. When its voltage reaches the preset positive threshold, the positive threshold comparator is turned on, the positive threshold switch is closed, and the control signal controls the electrical boundary conditions of the piezoelectric body to change to a short circuit, and the charge accumulated at the electrical boundary of the piezoelectric body is neutralized to dissipate electrical energy;

[0066] Step 4), when the deformation of the vibration suppression object in the positive direction reaches the maximum and then begins to decrease, the self-sensing signal decreases accordingly. When its voltage drops below the preset positive threshold, the positive threshold comparator disconnects, the positive threshold switch disconnects, and the control signal controls the electrical boundary condition of the piezoelectric body to change to an open circuit. The stiffness of the entire structure becomes larger, the ability to resist elastic deformation is strong, and the vibration displacement is reduced.

[0067] Step 5), the deformation of the vibration suppression object continues to decrease, and the self-sensing signal decreases accordingly. When its voltage drops below the preset negative threshold, the negative threshold comparator connects, the negative threshold switch closes, and the control signal controls the electrical boundary condition of the piezoelectric body to change to a short circuit. The charges accumulated at the electrical boundary of the piezoelectric body are neutralized to dissipate electrical energy, and the stiffness of the entire structure becomes smaller.

[0068] Step 6), when the deformation of the vibration suppression object in the negative direction reaches the maximum and then begins to decrease, the self-sensing signal increases accordingly. When its voltage rises above the preset negative threshold, the negative threshold comparator disconnects, the negative threshold switch disconnects, and the control signal controls the electrical boundary condition of the piezoelectric body to change to an open circuit. The stiffness of the entire structure becomes larger, the ability to resist elastic deformation is strong, and the vibration displacement is reduced.

[0069] Those skilled in the art of this technology can understand that unless otherwise defined, all terms (including technical terms and scientific terms) used here have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless defined as here.

[0070] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A sandwich - type piezoelectric self - sensing passive vibration suppression structure, whose vibration suppression object is a cantilever beam. The cantilever beam is a cylinder or a regular prism with a threaded blind hole at the center of one end face. It is characterized in that the sandwich - type piezoelectric self - sensing passive vibration suppression structure includes a piezoelectric body, a fixing block, a pre - tightening bolt and a passive control circuit; the piezoelectric body includes N piezoelectric units, where N is a natural integer greater than or equal to 1; each piezoelectric unit includes 4 two - partition piezoelectric ceramic sheets; the two - partition piezoelectric ceramic sheets have the same shape as the cross - section of the cantilever beam, with a through - hole at the center for the pre - tightening bolt to pass through, and are polarized along the thickness direction, and the polarization dividing line is a straight line passing through the center of the two - partition piezoelectric ceramic sheet; the 4 two - partition piezoelectric ceramic sheets are stacked in sequence. The polarization dividing lines of the first and second two - partition piezoelectric ceramic sheets are coplanar, the polarization dividing lines of the third and fourth two - partition piezoelectric ceramic sheets are coplanar, and the polarization dividing lines of the second and third two - partition piezoelectric ceramic sheets are perpendicular to each other; the polarization directions of the two partitions in the first two - partition piezoelectric ceramic sheet are the same, the polarization directions of the two partitions in the second two - partition piezoelectric ceramic sheet are the same, and the polarization directions of the first and second two - partition piezoelectric ceramic sheets are opposite; the polarization directions of the two partitions in the third two - partition piezoelectric ceramic sheet are opposite, the polarization directions of the two partitions in the fourth two - partition piezoelectric ceramic sheet are opposite, and the polarization directions of the third and fourth two - partition piezoelectric ceramic sheets are opposite; the upper end faces of the first two - partition piezoelectric ceramic sheet, the third two - partition piezoelectric ceramic sheet, and the lower end face of the fourth two - partition piezoelectric ceramic sheet are connected to each other to serve as the first connection point of the piezoelectric unit; the lower end face of the first two - partition piezoelectric ceramic sheet and the upper end face of the second two - partition piezoelectric ceramic sheet are connected to serve as the second connection point of the piezoelectric unit, and the lower end face of the third two - partition piezoelectric ceramic sheet and the upper end face of the fourth two - partition piezoelectric ceramic sheet are connected to serve as the third connection point of the piezoelectric unit; the fixing block is a column with the same cross - section shape as the cross - section of the cantilever beam, and has a through - hole or a counterbore through - hole along the axis for mating with the pre - tightening bolt; the pre - tightening bolt passes through the fixing block, N piezoelectric units in sequence and is threadedly connected to the threaded blind hole on the cantilever beam, clamping the N piezoelectric units between the fixing block and the cantilever beam; the first connection points of each piezoelectric unit are connected in series to serve as the grounding interface of the piezoelectric module, the second connection points of each piezoelectric unit are connected in series to serve as the first signal interface of the piezoelectric module, and the third connection points of each piezoelectric unit are connected in series to serve as the second signal interface of the piezoelectric module; the passive control circuit includes a resistor R1, a resistor R2, a resistor Rc, a capacitor Cr, an N - type mos - tube, an NPN - type triode, a P - type mos - tube, a PNP - type triode, a first diode and a second diode; the grounding interface of the piezoelectric module is electrically connected to one end of the resistor R1 and one end of the resistor Rc respectively. The first signal interface of the piezoelectric module is connected to the second signal interface of the piezoelectric module, one end of the capacitor Cr, the drain of the N - type mos - tube, and the drain of the P - type mos - tube respectively; The other end of the resistor R1 is connected to one end of the resistor R2, the source electrode of the N-type MOS transistor, and the source electrode of the P-type MOS transistor respectively; The other end of the capacitor Cr is connected to the other end of the resistor R2, the collector of the NPN-type triode, and the collector of the PNP-type triode respectively; The emitter of the NPN-type triode is connected to the gate of the P-type MOS transistor, and the base is connected to the negative electrode of the first diode; The emitter of the PNP-type triode is connected to the gate of the N-type MOS transistor, and the base is connected to the positive electrode of the second diode; The positive electrode of the first diode is connected to the other end of the resistor Rc and the negative electrode of the second diode respectively; Let the capacitance of the piezoelectric module be Cp, then R1*Cp = R2*Cr.

2. The sandwich-type piezoelectric self-sensing passive vibration suppression structure according to claim 1, characterized in that, N is taken as 2.

3. The vibration suppression method based on the sandwich-type piezoelectric self-sensing passive vibration suppression structure according to claim 1, characterized in that, includes the following processes: Let the N-type MOS transistor be a negative threshold switch, the P-type MOS transistor be a positive threshold switch, the NPN triode and the first diode form a positive threshold comparator, and the PNP triode and the second diode form a negative threshold comparator. When the vibration suppression object is disturbed and vibrates, the piezoelectric sensor generates a sensing signal due to the positive piezoelectric effect caused by the deformation. The sensing signal affects the components of the control module to perform the following periodic changes: Step 1), when the vibration suppression object undergoes bending vibration, the piezoelectric body generates deformation and the positive piezoelectric effect occurs. A voltage difference appears at the electrical boundary of the piezoelectric body, and an electrical signal is generated at the first signal interface or the second signal interface; Step 2), the passive control circuit separates the electrical signal generated by the piezoelectric body into a self-sensing signal for monitoring the electrical state and vibration state of the piezoelectric body and a control signal for controlling the electrical boundary conditions of the piezoelectric body through bridge balance; Step 3), the self-sensing signal increases as the vibration deformation of the vibration suppression object increases. When its voltage reaches the preset positive threshold, the positive threshold comparator is turned on, the positive threshold switch is closed, and the control signal controls the electrical boundary conditions of the piezoelectric body to change to a short circuit, and the charge accumulated at the electrical boundary of the piezoelectric body is neutralized to dissipate electrical energy; Step 4), when the vibration deformation of the vibration suppression object in the positive direction reaches the maximum and then begins to decrease, the self-sensing signal decreases accordingly. When its voltage drops below the preset positive threshold, the positive threshold comparator is turned off, the positive threshold switch is turned off, and the control signal controls the electrical boundary conditions of the piezoelectric body to change to an open circuit. The stiffness of the entire structure becomes larger, the ability to resist elastic deformation is strong, and the vibration displacement is reduced; Step 5), the vibration deformation of the vibration suppression object continues to decrease, the self-sensing signal decreases accordingly. When its voltage drops below the preset negative threshold, the negative threshold comparator is turned on, the negative threshold switch is closed, and the control signal controls the electrical boundary conditions of the piezoelectric body to change to a short circuit, and the charge accumulated at the electrical boundary of the piezoelectric body is neutralized to dissipate electrical energy, and the stiffness of the entire structure becomes smaller; Step 6), when the deformation of the vibration suppression object in the negative direction reaches the maximum, the deformation begins to decrease, and the self-sensing signal increases accordingly. When its voltage increases to higher than the preset negative threshold, the negative threshold comparator is disconnected, the negative threshold switch is disconnected, and the control signal controls the electrical boundary condition of the piezoelectric body to change to an open circuit. The stiffness of the entire structure becomes larger, the ability to resist elastic deformation is strong, and the vibration displacement is reduced.

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