A triboelectric nanogenerator and a test device

Abstract

An embodiment of the present invention provides a triboelectric nanogenerator and a test device. The generator is applied between the track and the roadbed slab of a railway system and is installed at the midpoint of the track section between every two adjacent sleepers. The triboelectric nanogenerator includes a layered structure and an insulating and waterproof encapsulation protection layer covering the layered structure. The layered structure sequentially includes an upper support layer, an upper electrode layer, a friction pair, a lower electrode layer, a lower support layer, and a buffer layer from top to bottom. By collecting the mechanical energy generated by the vibration of the track and the roadbed slab when a train passes by, the mechanical energy is converted into electrical energy for storage or directly supplying power to railway-related electrical equipment. The test device of the invention can study the electrical signal output performance of the triboelectric nanogenerator under different track vibration conditions and different friction pair gap designs.

Description

Technical Field

[0001] The embodiments of the present invention relate to a triboelectric nanogenerator, and particularly to a triboelectric nanogenerator and a test device, which are particularly applied between a subway track and a track slab. Background Art

[0002] With the development of the construction of underground rail transit in China, the operating mileage and traffic volume of subways have increased rapidly, and related operation safety issues have become increasingly prominent. The rail transit health monitoring system can monitor the operating status of the subway in real time, but there are still great challenges in the power supply problem of the monitoring system which contains a large number of sensors and related acquisition devices: if the traditional wired power supply form is adopted, since the distance between the power supply and some sensors is relatively far, the cable is easily damaged; if battery power supply is adopted, on the one hand, the battery needs to be replaced frequently, which greatly increases the labor cost, and on the other hand, the large-scale use of batteries also exacerbates the potential harm to the environment and the human body. Therefore, the energy harvesting technology that can collect environmental energy and convert it into electrical energy has received extensive attention. However, due to the limitations of the underground operating environment, energy harvesting devices such as solar energy and wind energy are not suitable for the subway system.

[0003] The triboelectric nanogenerator proposed by Professor Zhonglin Wang of the National Center for Nanoscience in 2012 (published in CN103368447A) is an efficient means of collecting environmental mechanical energy. However, at present, this triboelectric nanogenerator is only a concept machine and cannot be applied to complex environments. To apply it to the underground rail transit system, there are still the following deficiencies:

[0004] 1. The initial gap between the friction pairs of this triboelectric nanogenerator is fixed during preparation. When the deformation amplitude applied by the external force is less than the fixed gap, the friction pairs cannot come into contact to generate charge exchange; when the amplitude is much larger than the gap, the friction pairs will be subjected to a great external force and will inevitably be damaged. Therefore, it cannot be flexibly applied to various working conditions. In fact, the vibration of the track is affected by dozens of vehicle-track parameters such as vehicle speed, vehicle weight, and fastener stiffness, and its vibration amplitude varies greatly under various working conditions. Therefore, the traditional triboelectric nanogenerator is difficult to be directly applied to the vibration energy harvesting of subway tracks.

[0005] 2. This triboelectric nanogenerator is provided with a support body to provide a restoring force for the separation of two insulating materials. For application scenarios where the external force can make the triboelectric nanogenerator automatically return, such as the reciprocating vertical movement of the track that allows it to directly return, this support body structure actually hinders the flat and complete contact of the friction pairs and reduces the output performance of the generator.

[0006] 3. The triboelectric nanogenerator is not provided with a buffer layer. When the deformation provided by the external force is greater than the initial gap, the insulating material and the electrode material will be subjected to a huge external force, resulting in additional deformation and being easily damaged. Especially in the track system, the variable track displacement makes the deformation range of the triboelectric nanogenerator relatively large. When the track displacement is greater than the initial gap of the friction pair, the triboelectric nanogenerator is easily crushed.

[0007] 4. The triboelectric nanogenerator is not reasonably insulated and encapsulated. It should be considered in combination with the application scenario, especially the complex environment in the track.

[0008] 5. Its energy harvesting efficiency, output power, etc. are not tested and verified by designing a dedicated test device for the application scenario. Summary of the Invention

[0009] In view of this, the embodiments of the present invention provide a triboelectric nanogenerator and a test device, which solve the problem that the triboelectric nanogenerator can be flexibly applied to different vibration amplitude conditions of the track by setting a buffer layer, so as to collect the track vibration energy to supply power to the electrical equipment in the track.

[0010] The technical solutions for the embodiments of the present invention to solve the technical problems are as follows:

[0011] The embodiments of the present invention provide a triboelectric nanogenerator, which includes a layered structure and an insulating and waterproof encapsulation protection layer covering the layered structure. The layered structure sequentially includes an upper support layer, an upper electrode layer, a friction pair, a lower electrode layer, a lower support layer, and a buffer layer from top to bottom.

[0012] Further, the friction pair is composed of a top dielectric material layer and a bottom dielectric material layer. The top dielectric material layer and the bottom dielectric material layer have the same area and opposite polarities, and both are completely flattened and parallel to each other in the form of a thin film. An initial gap is reserved between the top dielectric material layer and the bottom dielectric material layer.

[0013] Further, the upper electrode layer and the lower electrode layer are copper foil sheets, which are respectively bonded to the upper surface of the top dielectric material layer and the lower surface of the bottom dielectric material layer. Wires are connected to the copper foil sheets for outputting current.

[0014] Further, the upper support layer and the lower support layer are acrylic plates, which are respectively bonded to the upper surface of the upper electrode layer and the lower surface of the lower electrode layer.

[0015] Further, the buffer layer is made of materials such as sponge and rubber, and is located on the surface of the lower support layer, playing an important role in enhancing the energy harvesting efficiency of the generator, buffering the train load, and protecting the structural safety of the triboelectric nanogenerator. The effect of the buffer layer is as follows: when the downward displacement amplitude of the track is greater than the gap between the top dielectric material and the bottom dielectric material of the friction pair, the buffer layer is compressed under force, causing the friction pair to move downward as a whole while maintaining contact, avoiding damage to the dielectric material due to the huge pressure between the wheel and the rail, and providing a certain reaction force to the friction pair to increase the output effect of the triboelectric nanogenerator.

[0016] Further, to facilitate the adjustment of the gap between the top dielectric material and the bottom dielectric material of the friction pair, a rigid cushion layer is provided below the buffer layer, that is, below the entire triboelectric nanogenerator. The thickness of the rigid cushion layer is calculated based on the track vibration amplitude and the overall height of the triboelectric nanogenerator, and is rigidly connected to the track slab. The material of the rigid cushion layer can be concrete or stainless steel.

[0017] Further, the initial gap between the friction pairs is less than or equal to the maximum track vibration amplitude. The initial gap between the top dielectric material and the bottom dielectric material of the friction pair is determined by the track vibration amplitude, making it less than or equal to the maximum track vibration amplitude to ensure that the friction pairs can be in full contact with each other during train operation.

[0018] Further, the vibration amplitude is determined by establishing a vehicle-track coupling vibration model and combining the modal analysis method and the Newmark numerical calculation method.

[0019] Further, the method for determining the vibration amplitude is as follows:

[0020] The dynamic control equations of the train and the track structure are respectively:

[0021]

[0022]

[0023] Where M t , C t , K t are respectively the mass matrix, damping matrix and stiffness matrix of the train, y t is the displacement vector of the train, F t is the external load applied to the train, including the train's own weight and the wheel-rail contact force; y r (x, t) and φ r (x, t) are respectively the vertical displacement and rotation angle of the track, E r I r and κA r G rThey are the flexural stiffness and shear stiffness of the track, respectively, and ρ r is the density, and A r is the cross-sectional area, and I r is the moment of inertia of the cross-section; F r (x, t) is the external load borne by the track; x is the track position and t is the time;

[0024] According to the idea of the modal superposition method, the track control equation is simplified to an ordinary differential equation, and numerical calculations are carried out by the Newmark method. Finally, the vibration amplitude of the track can be obtained, and the initial gap between the top dielectric material and the bottom dielectric material of the friction pair can be determined based on this.

[0025] Furthermore, the insulating, waterproof and encapsulating protective layer is located on the outer surface of the entire triboelectric nanogenerator and is made of a material with good insulating, waterproof, durability and flexibility. The insulating, waterproof and encapsulating protective layer leaves a wire connected to an external circuit outlet, and the circuit outlet is encapsulated in a polymer waterproof and flexible insulating sleeve.

[0026] It should be noted that multiple triboelectric nanogenerators can be connected in series to form a power supply circuit. This power supply circuit is sequentially connected to a voltage regulator rectifier, a voltage transformation device, an electrical energy storage device and a circuit output port connecting an electrical device. The power supply circuit is encapsulated in a polymer waterproof and flexible insulating sleeve.

[0027] The embodiment of the present invention also provides a triboelectric nanogeneration test device, including: a track model,

[0028] The track model includes wooden blocks for simulating sleepers and steel sheets for simulating the bottom surface of the track. Both ends of the steel sheet are respectively fixed to two wooden blocks by bolts. Steel blocks are arranged between the two wooden blocks, and a triboelectric nanogenerator is installed between the steel sheet and the steel block; there can be multiple steel sheets here to change the distance between the friction pairs at any time;

[0029] The triboelectric nanogenerator includes a layered structure and an insulating, waterproof and encapsulating protective layer covering the layered structure. The layered structure sequentially includes an upper support layer, an upper electrode layer, a friction pair, a lower electrode layer, a lower support layer and a buffer layer from top to bottom;

[0030] It also includes an exciter for providing a simulated track vibration load to the steel sheet, and a test device for measuring the vibration response generated by the exciter applied to the track model and measuring the output indexes of the triboelectric nanogenerator.

[0031] Furthermore, to improve the test accuracy, the length of the steel sheet simulating the bottom surface of the track should adopt the length of the track section between two sleepers in the actual track. At the same time, the width of the wooden block simulating the sleeper can be the same as that of the steel sheet, and the height of the wooden block only needs to be greater than the height of the triboelectric nanogenerator plus the friction pair gap.

[0032] Apply vibration loads including sine loads and triangular loads at the midpoint of the track model using exciters to more accurately simulate the load waveforms of track vibrations;

[0033] When using an oscilloscope and a galvanometer to record the voltage or current time history curves of the triboelectric nanogenerator, and a displacement meter to record the displacement time history curve of the midpoint of the track, the relationship between the output of the triboelectric nanogenerator and various parameters of the vibration load can be analyzed, and the corresponding relationship on the output signal and the displacement time history curve can also be analyzed.

[0034] Adopting the above technical solutions, the beneficial effects of the present invention are as follows:

[0035] The initial gap of the friction pair of the triboelectric nanogenerator of the present invention can be flexibly adjusted and can be applied to working conditions with different track vibration displacements. In addition, a buffer layer is provided at the lower part of the triboelectric nanogenerator. When the displacement of the steel rail increases due to the change in the train load, the friction pair can be protected from the impact damage of the train wheel-rail load, and the performance output can be improved. Therefore, the triboelectric nanogenerator can adapt to the track vibration characteristics, efficiently collect the track vibration energy, and thus supply energy to the electrical equipment in the track. The triboelectric nanogenerator is designed with a protective layer for the harsh working environment under the track and its own structural characteristics, improving its durability. And a test device for the performance of the triboelectric nanogenerator is designed according to the track vibration characteristics, which can predict the power generation efficiency of the generator and improve the generator design through indoor tests. Description of the Drawings

[0036] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0037] Figure 1 is a side view of the installation position of the triboelectric nanogenerator in the track provided by an embodiment of the present invention;

[0038] Figure 2 is a schematic structural diagram of the triboelectric nanogenerator provided by an embodiment of the present invention;

[0039] Figure 3 is a schematic structural diagram of the triboelectric nanogenerator provided by an embodiment of the present invention (part of the insulating and waterproof encapsulation protective layer is cut away);

[0040] Figure 4 is a schematic diagram of the working process of the triboelectric nanogenerator provided by an embodiment of the present invention;

[0041] Figure 5 is a curve of the change of the friction pair gap of the triboelectric nanogenerator provided by an embodiment of the present invention with the fastener stiffness;

[0042] Figure 6 is an axonometric schematic diagram of the triboelectric nanogenerator test device provided by an embodiment of the present invention;

[0043] Figure 7 is a front view schematic diagram of the triboelectric nanogenerator test device provided by an embodiment of the present invention;

[0044] Figure 8 is a top view schematic diagram of the triboelectric nanogenerator test device provided by an embodiment of the present invention;

[0045] Figure 9 is a left view schematic diagram of the triboelectric nanogenerator test device provided by an embodiment of the present invention;

[0046] Reference numerals in the figure: 1 - track; 2 - track fastener; 3 - sleeper; 4 - track slab; 5 - triboelectric nanogenerator; 6 - rigid cushion layer; 7 - upper support layer; 8 - upper electrode layer; 9 - top dielectric material layer; 10 - bottom dielectric material layer; 11 - lower electrode layer; 12 - lower support layer; 13 - buffer layer; 14 - insulating and waterproof encapsulation protection layer; 15 - wire; 16 - circuit outlet sleeve; 17 - initial position of the upper support layer; 18 - tribo - pair gap; 19 - steel sheet; 20 - wooden block; 21 - bolt; 22 - gasket; 23 - steel block; 24 - load application position. Detailed implementation manners

[0047] The following further elaborates on the detailed implementation manners of the present invention in conjunction with the accompanying drawings. For clarity and completeness, examples of changeable materials in the invention will be given. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art by only changing some materials or without creative labor fall within the scope of protection of the present invention.

[0048] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of this application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If this specific posture changes, the directional indications will also change accordingly.

[0049] Such as Figure 1As shown in the figure, an embodiment of the present invention provides a triboelectric nanogenerator, which is installed between the track 1 and the track slab 4 and is located at the midpoint between two adjacent sleepers 3. To adjust the initial gap of the friction pair of the triboelectric nanogenerator 5, a rigid cushion layer 6 made of concrete or steel with an appropriate height is used. The value of the friction pair gap should be selected to be slightly smaller than the maximum displacement generated by the track 1 when the train wheels pass by. Its specific value is related to the train speed, train weight, track 1 stiffness, track fastener 2 stiffness, etc.

[0050] This generator is applied between the track and the roadbed slab of the railway system, installed at the midpoint of the track section between every two adjacent sleepers. By collecting the mechanical energy generated by the vibration of the track and the roadbed slab when the train passes by, this mechanical energy is converted into electrical energy for storage or directly supply power to the electrical equipment related to the railway. This triboelectric nanogenerator is designed for the situation of track vibration and can adapt to the working environments of ground tracks and underground track systems. Especially for various wireless sensors in the track intelligent health monitoring system limited by long-distance power transmission, this triboelectric nanogenerator can provide continuous power supply for them, saving energy consumption, and is an advanced green energy technology.

[0051] As Figure 2 and Figure 3 As shown in the figure, the triboelectric nanogenerator 5 includes a layered structure and an insulating and waterproof encapsulation protection layer 14 covering the layered structure. The layered structure sequentially includes an upper support layer 7, an upper electrode layer 8, a friction pair, a lower electrode layer 11, a lower support layer 12, and a buffer layer 13 from top to bottom.

[0052] Among them, the friction pair is composed of a top dielectric material layer 9 made of commercial nylon film and a bottom dielectric material layer 10 made of polytetrafluoroethylene film. The top dielectric material layer 9 and the bottom dielectric material layer 10 have the same size, are completely flattened and parallel to each other, and there is an initial gap between them. An upper electrode layer 8 made of copper foil is bonded to the upper side of the top dielectric material layer 9, and an upper support layer 7 made of acrylic plate is bonded to its upper side. A lower electrode layer 11 made of copper foil is bonded to the lower side of the bottom dielectric material layer 10, and a lower support layer 12 made of acrylic plate is bonded to its lower side. A sponge or rubber buffer layer 13 is provided on its lower side. Wires 15 are provided on both the upper electrode layer 8 and the lower electrode layer 11, and the two strands of wires are gathered together and installed in the circuit outlet sleeve 16. A rubber sleeve is used as the insulating and waterproof encapsulation protection layer 14 outside the triboelectric nanogenerator. The upper part of the rubber sleeve is connected to the upper support layer 7, and the lower part is connected to below the buffer layer 13. The insulating and waterproof encapsulation protection layer 14 arches out slightly outward. When the overall height is squeezed by the track, it will not bend inward and affect the contact of the friction pair. The circuit outlet sleeve 16 passes through the rubber sleeve.

[0053] It should be noted that the circuits of multiple triboelectric nanogenerators can be connected in series to form a power supply circuit, and can be connected to the circuit output ports of a voltage stabilizing rectifier, a voltage transformation device, an electric energy storage device, and an electrical equipment. The electrical equipment mainly refers to the electrical equipment in the rail transit system, especially including the safety monitoring system of the track structure, and the energy storage device stores the surplus electric energy.

[0054] As Figure 4 shown, the working process of the triboelectric nanogenerator in the track can generally be divided into three states.

[0055] 1. When the train passes by, the track bends downward under the influence of the train load, driving the upper part of the triboelectric nanogenerator to move downward, causing the top dielectric material surface and the bottom dielectric material surface of the friction pair to contact and generate friction. At this time, because the two dielectric materials have opposite polarities, charge transfer occurs on the dielectric material surface. When the track further bends, it squeezes the buffer layer below the friction pair, increasing the reaction force on the friction pair and intensifying the charge transfer on the dielectric material surface.

[0056] 2. After the train wheels gradually leave the position where the triboelectric nanogenerator is located, the track gradually moves upward to return to the horizontal state under the influence of its own stiffness. At this time, it will drive the upper part of the triboelectric nanogenerator to move upward, causing the friction pair to gradually separate. A potential difference is generated between the two copper foils of the electrode layer adhered to the friction pair due to the change in distance. Since the dielectric material of the friction pair has an insulating function, this potential difference can only be balanced by the electron movement in the external circuit. Therefore, when the copper foils are connected with the wire in this process, directional electron movement will occur in the wire to generate current.

[0057] 3. When the next wheel gradually approaches the position where the triboelectric nanogenerator is located, the track bends downward again, causing the friction pair to gradually approach. A potential difference is generated between the two copper foils of the electrode layer due to the change in distance, and directional electron movement opposite to that when the friction pair separates will occur in the wire to generate current.

[0058] Along with the passing process of the train, multiple wheels continuously pass through the position where the triboelectric nanogenerator is located. Through the above process, the friction pair repeats contact - separation, thus generating pulsed current.

[0059] As Figure 5 shown, the gap of the friction pair of the triboelectric nanogenerator is controlled by the track vibration amplitude, and can be calculated and determined by establishing a vehicle - track coupling vibration model and combining the modal analysis method and the Newmark numerical method. Specifically:

[0060] It can be calculated and determined by establishing a vehicle - track coupling vibration model and combining the modal analysis method and the Newmark numerical calculation method. Among them, the dynamic control equations of the train and the track structure are respectively:

[0061]

[0062]

[0063] where M t 、C t 、K t are the mass matrix, damping matrix, and stiffness matrix of the train respectively, y t is the displacement vector of the train, F t is the external load applied to the train, including the self-weight of the train and the wheel-rail contact force; y r (x, t) and φ r (x, t) are the vertical displacement and rotation angle of the track respectively, E r I r and κA r G r are the flexural stiffness and shear stiffness of the track respectively, ρ r is the density, A r is the cross-sectional area, I r is the moment of inertia of the cross-section; F r (x, t) is the external load borne by the track; x is the track position and t is the time.

[0064] According to the idea of the modal superposition method, the track control equation is simplified to an ordinary differential equation, and numerical calculations are carried out by the Newmark method. Finally, the vibration displacement amplitude of the track can be obtained, and the initial gap between the top dielectric material and the bottom dielectric material of the friction pair is determined based on this.

[0065] In this example, the initial gap change curves of the friction pair under 6 different track fastener stiffnesses are considered. It is observed that: the gap of the friction pair decreases with the increase of the track fastener stiffness. Therefore, to ensure that the triboelectric nanogenerator obtains the maximum output voltage, the initial gap between the top dielectric material and the bottom dielectric material of the friction pair can be adjusted under different fastener stiffnesses (by adjusting the thickness of the rigid cushion 6). Figure 4 It also shows that when the wheel set continuously passes through the triboelectric nanogenerator, the gap between the dielectric materials of the friction pair experiences multiple alternating processes from 0 to the maximum value. Among them, the gap being 0 means that the two dielectric materials are in contact. This curve can be used as a reference for the working condition of the triboelectric nanogenerator.

[0066] Such as Figures 6 - 9As shown in the figure, an embodiment of the present invention further provides a triboelectric nanogenerator test device. The device includes an orbital model for testing the working performance of a single triboelectric nanogenerator mentioned above. A steel sheet 19 is used to replace the bottom surface of the track, and a wooden block 20 connected to a rigid base is used to replace the sleeper. The steel sheet 19 and the wooden block 20 are connected by bolts 21, and several shims 22 can be added between the steel sheet and the wooden block as required. The triboelectric nanogenerator is installed below the mid-span position of the steel sheet 19. Specifically, the upper support layer 7 of the triboelectric nanogenerator is bonded to the midpoint of the steel sheet, and the upper electrode layer 8 and the top dielectric material layer 9 are respectively connected below it. The bottom dielectric material layer 10 faces the top dielectric material layer 9, and the lower electrode layer 11 and the lower support layer 12 are bonded to the lower side. A buffer layer 13 is provided below the lower support layer 12. To reasonably adjust the initial gap between the friction pairs in the triboelectric nanogenerator, a lower cushion layer composed of multiple steel blocks 23 is provided below the buffer layer 13. The number of steel blocks can be increased or decreased to adjust the initial gap, and the number of shims 22 can also be finely adjusted to change the bottom net height of the steel sheet 19.

[0067] The orbital model is loaded by an exciter at the load application position 24, causing the steel sheet 19 to undergo simulated track vibration under train loads, and is a test device for measuring the vibration response generated by the exciter applied to the orbital model and measuring the output index of the triboelectric nanogenerator. The test equipment includes an oscilloscope, a galvanometer, a displacement meter, etc. The oscilloscope is connected to the upper electrode layer 8 and the lower electrode layer 11. When using the oscilloscope and the galvanometer to record the voltage or current time history curve of the triboelectric nanogenerator, the working performance of the triboelectric nanogenerator under this vibration load can be obtained by analyzing the oscilloscope graph and data. The displacement meter is used to record the displacement time history curve of the midpoint of the track, which can be used to analyze the relationship between the output of the triboelectric nanogenerator and various parameters of the vibration load, and also to analyze the corresponding relationship between the output signal and the displacement time history curve.

[0068] In addition to the adjustable exciter load and the initial gap of the friction pair, the types, thicknesses, areas, and surface microtopographies of the dielectric materials of the top dielectric material layer 9 and the bottom dielectric material layer 10 can also be changed to study the working performance of triboelectric nanogenerators with different materials. The material of the buffer layer 13 can also be selected as sponges, rubbers, etc. with different stiffnesses to study the working performance of triboelectric nanogenerators under different force characteristics.

[0069] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made using the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A triboelectric nanogenerator, characterized in that: The triboelectric nanogenerator includes a layered structure and an insulating and waterproof encapsulation protection layer covering the layered structure. The layered structure sequentially includes an upper support layer, an upper electrode layer, a friction pair, a lower electrode layer, a lower support layer, and a buffer layer from top to bottom. The triboelectric nanogenerator is applied to different vibration amplitude conditions of the track by setting the buffer layer, so as to collect the track vibration energy to supply energy to the electrical equipment in the track. The initial gap between the friction pairs is less than or equal to the maximum vibration amplitude of the track. The vibration amplitude is determined by establishing a vehicle-track coupling vibration model and combining the modal analysis method and the Newmark numerical calculation method. The method for determining the vibration amplitude is as follows: The dynamic control equations of the train and the track structure are respectively expressed as: Among which M t , C t , K t are respectively the mass matrix, damping matrix and stiffness matrix of the train, y t is the displacement vector of the train, F t is the external load applied to the train, including the self-weight of the train and the wheel-rail contact force; y r (x, t) and φ r (x, t) are respectively the vertical displacement and rotation angle of the track, E r I r and κA r G r are respectively the flexural stiffness and shear stiffness of the track, ρ r is the density, A r is the cross-sectional area, I r is the moment of inertia of the cross-section; F r (x, t) is the external load borne by the track; x is the track position and t is the time; According to the idea of the modal superposition method, the track control equation is simplified to an ordinary differential equation and numerically calculated by the Newmark method, and finally the vibration amplitude of the track is obtained.

2. The triboelectric nanogenerator according to claim 1, wherein, The friction pair is composed of a top dielectric material layer and a bottom dielectric material layer. The top dielectric material layer and the bottom dielectric material layer have the same area and opposite polarities, and both are completely paved and parallel to each other in the form of thin films. An initial gap is reserved between the top dielectric material layer and the bottom dielectric material layer.

3. A triboelectric nanogenerator according to claim 2, characterized in that, The upper electrode layer and the lower electrode layer are copper foil sheets, which are respectively bonded to the upper surface of the top dielectric material layer and the lower surface of the bottom dielectric material layer. Wires are connected to the copper foil sheets for outputting current.

4. A triboelectric nanogenerator according to claim 1, characterized in that, The upper support layer and the lower support layer are acrylic plates, which are respectively bonded to the upper surface of the upper electrode layer and the lower surface of the lower electrode layer.

5. A triboelectric nanogenerator according to claim 1, characterized in that, The buffer layer is made of sponge or rubber material and is located on the surface of the lower support layer.

6. A triboelectric nanogenerator according to claim 1, characterized in that, The insulating and waterproof encapsulation protection layer leaves a wire connected to an external circuit outlet, and the circuit outlet is encapsulated in a polymer waterproof flexible insulating sleeve.

7. A triboelectric nanogenerator test device, characterized in that, Including: A track model, The track model includes wooden blocks for simulating sleepers and steel sheets for simulating the bottom surface of the track. The two ends of the steel sheet are respectively fixed to the two wooden blocks by bolts. Steel blocks are arranged between the two wooden blocks. A triboelectric nanogenerator as described in any one of claims 1-6 is installed between the steel sheet and the steel block; It also includes an exciter for providing a simulated track vibration load to the steel sheet, and a test device for measuring the vibration response generated by the exciter applied to the track model and measuring the output indexes of the triboelectric nanogenerator.

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