A vibration-damping and energy-capturing device for a floating slab

Abstract

The application provides a damping and energy capturing device for a floating slab and belongs to the technical field of piezoelectric energy capturing. The damping and energy capturing device comprises a vibration absorbing layer, a force transmission layer, a piezoelectric energy conversion layer, a heterogeneous stress amplification layer, a damping and energy absorbing column and a pressure bearing body. The vibration absorbing layer, the piezoelectric energy conversion layer and the heterogeneous stress amplification layer are in a disc type structure, the pressure bearing body is in a semi-spherical shell structure, the lower surface of the vibration absorbing layer is connected with the force transmission layer, the force transmission layer is connected with the upper surface of the piezoelectric energy conversion layer, the lower surface of the piezoelectric energy conversion layer is bonded with the upper surface of the heterogeneous stress amplification layer, the lower surface of the heterogeneous stress amplification layer is bonded with the top of the damping and energy absorbing column, and the bottom of the damping and energy absorbing column is bonded with the bottom of the pressure bearing body. The damping and energy capturing device for the floating slab can effectively reduce the vibration generated by the train running on the track, effectively reduce the battery replacement frequency and power supply pressure of the urban rail transit facility, and improve the safety and economy of the tunnel rail transit operation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of piezoelectric energy harvesting, and particularly relates to a damping and energy harvesting device for a floating slab. BACKGROUND

[0002] In recent years, with the continuous development of the economy and the continuous acceleration of the construction of urban infrastructure, the demand for urban transportation is growing. Urban rail transit has become a reliable choice for solving traffic congestion, noise and air pollution under the background of urban modernization because of its large capacity, high speed, safety and reliability, and accurate arrival time. However, with the continuous expansion of rail transportation demand and operating mileage, the vibration problem caused by urban rail operation has a greater impact on the surrounding environment. The current measures to deal with the vibration problem mainly consist of two aspects: buffer damping and isolation damping. The first measure is isolation damping, which usually isolates the track bed and the structural foundation as a whole with an elastic body to deal with the vibration caused by vehicle operation. The other measure is to use elastic materials in the structures such as rails, fasteners and sleepers on the upper part of the track to buffer and attenuate the vibration from the vehicle operation. The latter damping measure is more commonly used in reality, but the damping effect is often insufficient and needs to be further improved.

[0003] In addition, the operation environment of urban rail transit is mostly underground, and the structural safety and operational fluency require a complete and comprehensive monitoring sensor system to ensure that the subway operation is always in a safe, fast and smooth use environment. However, the monitoring sensor network nodes usually require continuous input of external power, and when they encounter unexpected situations and lose external power input, the sensors are prone to be in a downtime state. When using battery power, the downtime probability is small, but the life cycle of the sensor is seriously dependent on the use time of the internal battery, and the replacement of the battery during operation and the disposal of the waste battery are time-consuming and labor-intensive, and have low environmental friendliness. As a material that can generate electricity when subjected to pressure, PZT-5H can obviously generate stable and objective current in the periodic load environment of urban rail transit operation, providing a power source for the battery in the battery-powered sensor, thereby reducing the frequency of battery replacement. Therefore, a new technology should be developed to combine PZT-5H with the structures in urban rail transit to achieve functional diversification. SUMMARY

[0004] In view of the above-mentioned technical problems, the application provides a device capable of reducing vibration and harvesting energy, which can generate electric energy from the periodic load generated during train operation and provide it to the power-consuming devices and facilities in the tunnel or store the energy on the basis of reducing the vibration generated by the train operation in urban rail transit.

[0005] To achieve the above-mentioned purposes, the technical solutions of the application are as follows:

[0006] A vibration damping and energy harvesting device for a floating slab includes a vibration-absorbing layer, a force-transmitting layer, a piezoelectric energy conversion layer, a heterogeneous stress amplification layer, a vibration-damping energy-absorbing column, and a pressure-bearing body. The vibration-absorbing layer, the piezoelectric energy conversion layer, and the heterogeneous stress amplification layer are disc-shaped structures, and the pressure-bearing body is a hemispherical shell structure. The lower surface of the vibration-absorbing layer is connected to the force-transmitting layer, the force-transmitting layer is connected to the upper surface of the piezoelectric energy conversion layer, the lower surface of the piezoelectric energy conversion layer is connected to the upper surface of the heterogeneous stress amplification layer, the lower surface of the heterogeneous stress amplification layer is connected to the top of the vibration-damping energy-absorbing column, and the bottom of the vibration-damping energy-absorbing column is connected to the bottom of the pressure-bearing body. The vibration-absorbing layer and the piezoelectric energy conversion layer are connected by a first limiting ring, and the piezoelectric energy conversion layer, the heterogeneous stress amplification layer, and the pressure-bearing body are connected by a second limiting ring.

[0007] Furthermore, the first limiting ring and the second limiting ring are provided with annular protrusions inside.

[0008] Furthermore, the vibration-absorbing layer is made of a polymer rubber material.

[0009] Furthermore, the force transmission layer is composed of several springs, which are evenly distributed between the vibration absorption layer and the piezoelectric energy conversion layer.

[0010] Furthermore, a limiting groove is provided on the lower surface of the force transmission layer and the upper surface of the piezoelectric energy conversion layer, and the spring is disposed in the limiting groove.

[0011] Furthermore, the piezoelectric energy conversion layer is a piezoelectric sheet made of PZT-5H material, and wires are connected to the upper and lower surfaces of the piezoelectric energy conversion layer.

[0012] Furthermore, the upper surface of the heterogeneous stress amplification layer is provided with cylindrical protrusions, and the edge of the lower surface of the heterogeneous stress amplification layer is provided with annular protrusions. The center of the lower surface of the heterogeneous stress amplification layer is connected to the vibration damping and energy absorption column.

[0013] Furthermore, the vibration damping and energy-absorbing column includes a hollow cylinder and a metal protective layer disposed along the axial direction of the hollow cylinder. The hollow cylinder is provided with a supporting spring and filled with high-pressure gas.

[0014] Furthermore, a platform is provided at the bottom of the pressure-bearing body, the vibration damping and energy-absorbing column is provided on the platform, and a rust-proof layer is provided on the surface of the pressure-bearing body.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] 1. By setting the vibration absorbing layer made of high polymer rubber material, the force transmission layer of spring structure and the damping energy absorbing column with support spring and high pressure gas on the lower surface of the floating plate, the vibration generated by the train running on the floating plate track bed can be effectively reduced by the high damping characteristics of the three, and the environmental pollution caused by rail transit vibration can be reduced.

[0017] 2. By setting the piezoelectric energy conversion layer made of PZT-5H material, the electric energy generated when the train is loaded on the floating plate can be generated, and the generated electric energy can be transmitted to the monitoring sensor element or energy storage element in the urban rail transit, which can effectively reduce the battery replacement frequency and power supply pressure of the monitoring sensor element in the urban rail transit facility, reduce the downtime probability, and improve the safety and economy of the rail transit operation in the tunnel. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of the overall structure of the present application;

[0019] Figure 2 is a schematic diagram of the explosion structure of the present application;

[0020] Figure 3 is a schematic diagram of the upper surface structure of the heterogeneous stress amplification layer of the present application;

[0021] Figure 4 is a schematic diagram of the lower surface structure of the heterogeneous stress amplification layer of the present application;

[0022] Figure 5 is a schematic diagram of the structure of the damping energy absorbing column of the present application;

[0023] Figure 6 is a schematic diagram of the cross-sectional structure of the damping energy absorbing column of the present application;

[0024] Figure 7 is a schematic diagram of the pressure bearing body structure of the present application;

[0025] Figure 8 is a schematic diagram of the upper surface structure of the piezoelectric energy conversion layer of the present application;

[0026] Figure 9 is a schematic diagram of the lower surface structure of the force transmission layer of the present application;

[0027] Figure: 1 vibration absorbing layer, 2 force transmission layer, 20 spring, 3 piezoelectric energy conversion layer, 30 limit groove, 4 heterogeneous stress amplification layer, 40 cylindrical protrusion, 41 ring-shaped protrusion, 5 damping energy absorbing column, 50 hollow cylinder, 51 metal protective shell, 52 support spring, 6 pressure bearing body, 60 platform, 7 first limit ring, 70 ring-shaped protrusion, 8 second limit ring. DETAILED DESCRIPTION

[0028] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative efforts on the basis of the described embodiments belong to the protection scope of the present application.

[0029] Referring to FIGS. 1-9, the present application provides a damping and energy trapping device for a floating slab, which comprises a vibration absorbing layer 1, a force transmission layer 2, a piezoelectric energy conversion layer 3, a heterogeneous stress amplification layer 4, a damping and energy absorbing column 5, and a pressure bearing body 6. The vibration absorbing layer 1, the piezoelectric energy conversion layer 3, and the heterogeneous stress amplification layer 4 are all disc-shaped structures, the force transmission layer 2 is a spring structure, and the pressure bearing body 6 is a semi-spherical shell structure. The upper surface of the vibration absorbing layer 1 is bonded together with the lower surface of the track floating slab track bed of a train, and the specific mode can be bonding by grouting. The lower surface of the vibration absorbing layer 1 is connected with the force transmission layer 2, the force transmission layer 2 is connected with the upper surface of the piezoelectric energy conversion layer 3, the lower surface of the piezoelectric energy conversion layer 3 is bonded with the upper surface of the heterogeneous stress amplification layer 4, the lower surface of the heterogeneous stress amplification layer 4 is bonded with the top of the damping and energy absorbing column 5, the bottom of the damping and energy absorbing column 5 is bonded with the bottom of the pressure bearing body 6, the bottom of the pressure bearing body is provided with a platform 60, and the damping and energy absorbing column is welded on the platform 60. The vibration absorbing layer 1 is made of high polymer rubber material, and its thickness can be designed according to actual needs to achieve the optimal damping and energy trapping effect. In this embodiment, the vibration absorbing layer 1 is made of polyurethane material, and its thickness is 30 mm. The force transmission layer 2 is composed of a plurality of springs 20, which are uniformly distributed between the vibration absorbing layer 1 and the piezoelectric energy conversion layer 3. In this embodiment, the number of springs 20 is three, and the positions of the three springs are respectively located on the vertices of an equilateral triangle whose center is aligned with the centers of the vibration absorbing layer 1 and the piezoelectric energy conversion layer 3. The center of the spring 20 is aligned with the vertex of the equilateral triangle, and the spring 20 is a short spring made of high-strength metal. The piezoelectric energy conversion layer 3 is a piezoelectric sheet made of PZT-5H material, and wires for transmitting electric energy are arranged on the upper and lower surfaces of the piezoelectric sheet. The electric charge generated inside the piezoelectric sheet can be transmitted to external power elements or energy storage elements through the wires. When installing the wires, the wires can be welded with the piezoelectric sheet by tin electrodes. The thickness and radius of the piezoelectric energy conversion layer 3 can be selected according to actual needs. In this embodiment, the circular piezoelectric sheet made of PZT-5H has a radius of 200 mm and a thickness of 30 mm. The electric energy generated by the piezoelectric energy conversion layer 3 can be obtained by finite element numerical simulation.

[0030] The heterogeneous stress amplification layer 4 is made of rubber material, and the so-called heterogeneous refers to the uneven surface, and the upper surface is provided with a cylindrical protrusion 40, and the lower surface edge is provided with a discontinuous annular protrusion 41, which is used to connect with the edge of the pressure bearing body 6, and the center of the lower surface of the heterogeneous stress amplification layer 4 is connected with the damping energy absorption column 5. By setting the protrusion structure on the upper and lower surfaces of the heterogeneous stress amplification layer 4, the piezoelectric energy conversion layer 3 placed above the heterogeneous stress amplification layer 4 can be subjected to greater force inside when it is extruded, because the protrusions on the surface of the heterogeneous stress amplification layer 4 can make the contact area of the piezoelectric energy conversion layer 3 and the heterogeneous stress amplification layer 4 smaller, in the case that the load inside the piezoelectric energy conversion layer 3 does not change, the contact area becomes smaller, the stress inside it becomes larger, so that it can generate more electric energy. The piezoelectric energy conversion layer 3 is pressed and energy is captured according to the d33 mode, and electric energy is generated according to the positive piezoelectric effect of the piezoelectric material of the piezoelectric energy conversion layer 3. The working mode of d33 is that the stress direction is the same as the polarization direction, which is suitable for the case that the piezoelectric sheet is deformed by pressure.

[0031] The theoretical charge amount Q generated by a single composite energy-capturing and vibration-reducing unit is calculated according to the following formula:

[0032] Q = d33 F

[0033] Wherein, d33 is the piezoelectric strain constant, with the unit of C / N. F is the force perpendicular to the upper and lower surfaces of the piezoelectric sheet, with the unit of N.

[0034] The voltage U0 generated by a single composite energy-capturing and vibration-reducing unit is calculated according to the following formula:

[0035]

[0036] Wherein, T is the stress perpendicular to the upper and lower surfaces of the piezoelectric sheet, with the unit of Pa, H is the thickness of a single piezoelectric sheet, with the unit of m, is the dielectric constant, with the unit of F / m.

[0037] The electric energy E0 converted by a single composite energy-capturing and vibration-reducing unit through piezoelectric effect is calculated according to the following formula:

[0038]

[0039] Wherein, A is the area of the polar surface of the piezoelectric sheet, with the unit of m².

[0040] The shock-absorbing energy-absorbing column 5 comprises a hollow cylinder 50 and a metal protective shell 51 arranged axially on the hollow cylinder 50, the hollow cylinder 50 is made of rubber material, and a supporting spring 52 for supporting and high-pressure gas filled are arranged in the hollow cylinder 50, the top of the shock-absorbing energy-absorbing column 5 is connected with the lower surface center of the heterogeneous stress amplification layer 4 through the metal protective shell 51, and the bottom of the shock-absorbing energy-absorbing column 5 is welded with the bottom of the pressure-bearing body 6. By setting the shock-absorbing energy-absorbing column 5 in the form of the combination of the supporting spring 52 and the high-pressure gas filled in the hollow cylinder 50, the damping of the shock-absorbing energy-absorbing column 5 can be improved, and the vibration generated when the load is transmitted to the shock-absorbing energy-absorbing column 5 can be effectively reduced.

[0041] In order to prevent the pressure-bearing body 6 from corroding during use, improve the service life thereof, and improve the service life of the whole device, an anti-rust layer is further arranged on the surface of the pressure-bearing body 6. Moreover, the shape of the pressure-bearing body 6 can also be an oval or rectangular shape, and correspondingly, the shapes of the shock-absorbing layer 1, the piezoelectric energy conversion layer 3 and the heterogeneous stress amplification layer 4 located above the pressure-bearing body 6 can also be oval or rectangular.

[0042] In order to keep the spring structure of the force transmission layer 2 stable when compressed between the vibration absorption layer 1 and the piezoelectric energy conversion layer 3, a limiting groove 30 is arranged on the lower surface of the force transmission layer 2 and the upper surface of the piezoelectric energy conversion layer 3, and the spring 20 of the force transmission layer 2 is embedded in the limiting groove 30; at the same time, in order to make the vibration absorption layer 1, the force transmission layer 2, the piezoelectric energy conversion layer 3, the heterogeneous stress amplification layer 4, the vibration absorption and energy absorption column 5 and the pressure bearing body 6 form an integral structure, and improve the stability of the overall device, the vibration absorption layer 1 and the piezoelectric energy conversion layer 3 are fixedly connected through the first limiting ring 7, the piezoelectric energy conversion layer 3, the heterogeneous stress amplification layer 4 and the pressure bearing body 6 are fixedly connected through the second limiting ring 8, the first limiting ring 7 and the second limiting ring 8 are circular ring structures, the inner diameter of the first limiting ring 7 is the same as the radius of the vibration absorption layer 1 and the piezoelectric energy conversion layer 3, and the height is slightly greater than the distance between the vibration absorption layer 1 and the piezoelectric energy conversion layer 3 when the vibration absorption layer 1, the force transmission layer 2 and the piezoelectric energy conversion layer 3 are combined; the inner diameter of the second limiting ring 8 is the same as the radius of the piezoelectric energy conversion layer 3 and the heterogeneous stress amplification layer 4, and the height is slightly greater than the height of the protrusions on the surface of the heterogeneous stress amplification layer 4, the first limiting ring 7 and the second limiting ring 8 are internally provided with annular protrusions 70, the lower edge of the vibration absorption layer 1, the upper edge of the piezoelectric energy conversion layer 3 and the annular protrusions 70 in the first limiting ring 7 are matched and embedded, the lower edge of the piezoelectric energy conversion layer 3, the heterogeneous stress amplification layer 4 and the annular protrusions 70 of the second limiting ring 8 are matched and embedded, by arranging the annular protrusions 70 in the first limiting ring 7 and the second limiting ring 8, the first limiting ring 7 and the second limiting ring 8 can be prevented from moving vertically, and the entire device can also be kept stable under load.

[0043] The vibration absorption and energy absorption device for the floating slab provided by the application is used in specific use, and is bonded to the lower surface of the floating slab track bed through the vibration absorption layer 1, when the train passes above the floating slab track bed, the load of the floating slab track bed and the train is transmitted to the force transmission layer 2 through the vibration absorption layer 1, the force transmission layer 2 transmits the load to the piezoelectric energy conversion layer 3, the piezoelectric sheet of the piezoelectric energy conversion layer 3 generates electric energy under pressure, the generated electric energy is transmitted to external electrical devices or energy storage elements through wires, and the piezoelectric energy conversion layer 3 can also transmit the load received to the vibration absorption and energy absorption column 5 through the heterogeneous stress amplification layer 4, the train load is transmitted layer by layer through the vibration absorption layer 1, the spring structure of the force transmission layer 2 and the vibration absorption and energy absorption column 5, and the structure with high damping characteristics can effectively reduce the vibration generated when the train runs on the track.

[0044] The embodiments of the present application are described in detail above with reference to the accompanying drawings, but the present application is not limited to the described embodiments. Various changes, modifications, replacements, and variations of the embodiments can be made by those skilled in the art without departing from the principles and spirit of the present application, and still fall within the scope of the present application.

Claims

1. A vibration damping and energy harvesting device for a floating plate, characterized in that: The structure includes a vibration-absorbing layer (1), a force-transmitting layer (2), a piezoelectric energy conversion layer (3), a heterogeneous stress amplification layer (4), a vibration-damping energy-absorbing column (5), and a pressure-bearing body (6). The vibration-absorbing layer (1), the piezoelectric energy conversion layer (3), and the heterogeneous stress amplification layer (4) are disc-shaped structures, and the pressure-bearing body (6) is a hemispherical shell structure. The lower surface of the vibration-absorbing layer (1) is connected to the force-transmitting layer (2), and the force-transmitting layer (2) is connected to the upper surface of the piezoelectric energy conversion layer (3). The lower surface of layer (3) is connected to the upper surface of the heterogeneous stress amplification layer (4), the lower surface of the heterogeneous stress amplification layer (4) is connected to the top of the vibration damping and energy absorption column (5), the bottom of the vibration damping and energy absorption column (5) is connected to the bottom of the pressure-bearing body (6), the vibration absorption layer (1) and the piezoelectric energy conversion layer (3) are connected by the first limiting ring (7), and the piezoelectric energy conversion layer (3) is connected to the heterogeneous stress amplification layer (4) and the pressure-bearing body (6) by the second limiting ring (8). The first limiting ring (7) and the second limiting ring (8) are provided with annular protrusions (70); The upper surface of the heterogeneous stress amplification layer (4) is provided with cylindrical protrusions (40), and the edge of the lower surface of the heterogeneous stress amplification layer (4) is provided with annular protrusions (41). The center of the lower surface of the heterogeneous stress amplification layer (4) is connected to the vibration damping and energy absorption column (5). The vibration damping and energy absorbing column (5) includes a hollow cylinder (50) and a metal protective shell (51) disposed in the axial direction of the hollow cylinder (50). The vibration damping and energy absorbing column (5) is connected to the heterogeneous stress amplification layer (4) and the pressure bearing body (6) through the metal protective shell (51). The hollow cylinder (50) is provided with a support spring (52) and filled with high-pressure gas.

2. The vibration damping and energy harvesting device for a floating plate according to claim 1, characterized in that: The vibration-absorbing layer (1) is made of polymer rubber material.

3. The vibration damping and energy harvesting device for a floating plate according to claim 1, characterized in that: The force transmission layer (2) is composed of several springs (20), which are evenly distributed between the vibration absorption layer (1) and the piezoelectric energy conversion layer (3).

4. The vibration damping and energy harvesting device for a floating plate according to claim 3, characterized in that: The lower surface of the force transmission layer (2) and the upper surface of the piezoelectric energy conversion layer (3) are provided with a limiting groove (30), and the spring (20) is disposed in the limiting groove (30).

5. The vibration damping and energy harvesting device for a floating plate according to claim 1, characterized in that: The piezoelectric energy conversion layer (3) is a piezoelectric sheet made of PZT-5H material, and the upper and lower surfaces of the piezoelectric energy conversion layer (3) are connected with wires.

6. The vibration damping and energy harvesting device for a floating plate according to claim 1, characterized in that: The pressure-bearing body (6) has a platform (60) at its bottom, the vibration damping and energy-absorbing column is set on the platform (60), and the surface of the pressure-bearing body (6) is provided with an anti-rust layer.

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