Piezoelectric energy harvesting device and method based on mechanical behaviors of asphalt pavement structure layer

Abstract

The invention discloses a piezoelectric energy harvesting device and method based on mechanical behaviors of a bituminous pavement structural layer, the piezoelectric energy harvesting device comprises a pressed area, a sheared area and a pulled area which are sequentially arranged from top to bottom, the sheared area is formed by joggling an upper tooth-shaped structure and a lower tooth-shaped structure, a clamping block is arranged between the upper tooth-shaped structure and the lower tooth-shaped structure, the pulled area is of an inverted arch structure, and the clamping block is arranged between the upper tooth-shaped structure and the lower tooth-shaped structure. The upper tooth-shaped structure comprises an upper tooth end and an upper tooth root, the lower tooth-shaped structure comprises a lower tooth end and a lower tooth root, and gaps are formed between the upper tooth end and the lower tooth root and between the upper tooth root and the lower tooth end. In the application, multiple areas are arranged and matched with the structural layer of the asphalt pavement, so that comprehensive response to multiple mechanical effects is realized, energy can be efficiently collected, stored and utilized, mechanical energy can be continuously and efficiently converted into electric energy under complex traffic load and variable environmental conditions, and the energy utilization efficiency is improved. And the device is not only high in adaptability and high in efficiency, but also excellent in stability and durability.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric energy harvesting technology, and in particular to a piezoelectric energy harvesting device and method based on the mechanical behavior of an asphalt pavement structure layer. Background Art

[0002] In the context of energy shortage, we try to find new energy sources to alleviate energy shortage and reduce pollution. There are many ways, among which the energy available on the road surface is very large. my country's transportation is developing very rapidly. In the huge transportation system, by the end of 2022, the total mileage of my country's roads will reach 5.35 million kilometers, of which 177,000 kilometers of expressways will be open to traffic, ranking first in the world.

[0003] With the rapid development of urban scale and urban transportation, the energy generated by road vibration caused by various vehicles is huge, and part of the energy is diffused into the surrounding environment in the form of heat and noise, resulting in energy waste. The power system of urban transportation is the basic driving force for the construction and operation of the intelligent transportation system. However, the complexity of the power supply system in urban roads and the urgency of the implementation of intelligent transportation have formed a prominent contradiction. For example, it is difficult to connect the geomagnetic detector installed in the existing urban roads to the power system of urban transportation, so disposable batteries are used for power supply, but its normal power supply time is only 1-2 years, which has become a problem for the monitoring system of urban transportation.

[0004] At present, pavement voltage energy harvesting technology based on voltage effect shows significant potential for converting mechanical energy into electrical energy. Therefore, in traditional piezoelectric energy harvesting devices, stacked, arched, bridged or cymbal structures are usually adopted. The mechanical behavior of the overall structural layer of the pavement is rarely considered in the design of piezoelectric energy harvesting devices. The structural response characteristics of asphalt pavement are not combined, the structure is not reasonable, and the piezoelectric energy cannot be fully collected. Summary of the invention

[0005] In order to solve the problem that the existing piezoelectric energy harvesting devices rarely consider the mechanical behavior of the overall structural layer of the piezoelectric energy harvesting device, do not combine the structural response characteristics of the asphalt pavement, the structure is not reasonable, and the piezoelectric energy cannot be fully collected, the present invention provides a piezoelectric energy harvesting device and method based on the mechanical behavior of the asphalt pavement structural layer. The technical scheme adopted is as follows: According to the first aspect of the present application, the present application provides a piezoelectric energy harvesting device based on the mechanical behavior of an asphalt pavement structural layer, the piezoelectric energy harvesting device comprises a compression zone, a shear zone and a tension zone arranged in sequence from top to bottom, wherein the compression zone is a rectangular structure, the shear zone is formed by mortise and tenoning an upper toothed structure and a lower toothed structure, a clamping block is arranged between the upper toothed structure and the lower toothed structure along the width direction of the piezoelectric energy harvesting device, and the tension zone is an inverted arch structure; Among them, the upper tooth-like structure includes an upper tooth end and an upper tooth root, and the lower tooth-like structure includes a lower tooth end and a lower tooth root. Along the height direction of the piezoelectric energy capture device, there are gaps between the upper tooth end and the lower tooth root, and between the upper tooth root and the lower tooth end.

[0006] In some embodiments, each area of ​​the piezoelectric energy capture device is a piezoelectric ceramic, and the piezoelectric ceramic is a piezoelectric ceramic lead titanate material, wherein the pressure-bearing area is composed of at least one piece of the piezoelectric ceramic stack, and the clamp is a rectangular piezoelectric ceramic.

[0007] In some embodiments, the length, width and height dimensions of the piezoelectric energy harvesting device are 150mm×150mm×150mm, wherein along the height direction of the piezoelectric energy harvesting device, the height of the compression zone is 20mm, the height of the tension zone is 15mm, and the height dimension of the gap is 5-15mm.

[0008] In some embodiments, along the width direction of the piezoelectric energy harvesting device, the width dimension of the upper tooth root is 4-5 mm, and the width dimension of the lower tooth root is 3-15 mm.

[0009] In some embodiments, the tension zone includes an inclined portion and a horizontal portion, the inclined portion is connected to the shear zone, and an extending direction of the horizontal portion is parallel to a width direction of the shear zone.

[0010] In some embodiments, along the width direction of the piezoelectric energy harvesting device, the width dimension of the horizontal portion is 0-100 mm.

[0011] According to the second aspect of the present application, the present application provides a method based on the mechanical behavior of an asphalt pavement structure layer, comprising the following steps: Step 1: By establishing a three-dimensional finite element model of the asphalt asphalt pavement structure, applying a tire static load on it, and obtaining the mechanical characteristics of different layers of the asphalt asphalt pavement structure; Step 2: Analyze and determine the mechanical characteristics of different layers of the asphalt asphalt pavement structure layer, as well as the corresponding stress-strain laws at different depths of the asphalt asphalt pavement structure layer; Step 3: Based on the mechanical characteristics, design a piezoelectric energy harvesting device and conduct relevant experiments.

[0012] In some embodiments, step 3 includes the following steps: Step 31: According to the mechanical characteristics, the corresponding piezoelectric energy harvesting device having a compression zone, a shear zone and a tension zone is established, and the shear deformation is calculated. Since the shear zone will undergo shear deformation when subjected to shear force, the shear deformation formula of the shear zone is: ; in, δ is the relative shear deformation (shear displacement), Q is the shear force acting on the device, L is the length of the device in the direction of shear force, G is the shear modulus of the material, A is the cross-sectional area of ​​the device; Step 32: Optimize the piezoelectric energy harvesting device using orthogonal experiments to determine the solution for the geometric parameters required for the piezoelectric energy harvesting device.

[0013] Compared with the prior art, the present invention has the following technical advances: The present invention arranges a compression zone of a rectangular structure, a shear zone formed by mortise and tenon joints of multiple tooth-like structures, and a tension zone of an inverted arch structure to form a piezoelectric energy capture device. During use, multiple regions can be matched with the structural layers of the road surface to achieve a comprehensive response to various mechanical effects (such as compression, shear and tension), so that energy can be efficiently collected, stored and utilized, and further, mechanical energy can be continuously and efficiently converted into electrical energy under complex traffic loads and changing environmental conditions. The piezoelectric energy capture device of the present application is not only highly adaptable and efficient, but also has excellent stability and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0015] In the attached picture: Figure 1 Schematic diagram of a conventional piezoelectric energy harvesting device; Figure 2 It is a schematic structural diagram of the piezoelectric energy harvesting device of the present invention; Figure 3 for Figure 2 Cross-sectional view of AA.

[0016] Figure 4 is a structural diagram of the piezoelectric energy harvesting device of the present invention; Figure 5 This is a diagram showing the use state of the piezoelectric energy harvesting device of the present invention; Figure 6 A reference usage state diagram of the piezoelectric energy harvesting device of the present invention; Figure 7 for Figure 5 A magnified circuit diagram of the piezoelectric energy harvesting device in the middle H region; Figure 8 It is a step diagram of the method based on the mechanical behavior of asphalt pavement structure layer of the present invention; Fig. 9A line graph showing the distribution of the extreme vertical stress of the pavement along the depth direction of the present invention; Fig.10 A line graph showing the variation of the extreme value of the vertical shear stress of the pavement with depth according to the present invention; Fig.11 A line graph showing the distribution of the extreme longitudinal tensile strain of the pavement of the present invention along the depth direction; Fig.12 It is the average value diagram of each level in the present invention; Fig.13 This is a potential display diagram of a traditional piezoelectric energy harvesting device; Fig.14 This is a potential display diagram of the piezoelectric energy harvesting device of the present invention.

[0017] In the figure: 100', conventional piezoelectric energy capture device; 1', compression zone; 2', shear zone; 3', tension zone; 100, piezoelectric energy capture device; 1, compression zone; 2, shear zone; 20, upper tooth structure; 201, upper tooth end; 202, upper tooth root; 21, lower tooth structure; 211, lower tooth end; 212, lower tooth root; 22, clamping block; 23, gap; 3, tension zone; 30, inclined portion; 31, horizontal portion; 200, asphalt pavement; 4, upper layer; 5, middle layer; 6, lower layer; 7, base layer; 8, soil foundation; 9, vehicle. DETAILED DESCRIPTION

[0018] The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments. The embodiments of the present invention will be described below in conjunction with the accompanying drawings.

[0019] like Figure 1 As shown, the conventional piezoelectric energy harvesting device 100' comprises a compression zone 1', a shear zone 2' and a tension zone 3'. The conventional piezoelectric energy harvesting device 100' usually adopts a stacked, arched, bridged or cymbal-shaped structure. The mechanical behavior of the overall structural layer of the pavement is seldom considered in the design of the piezoelectric energy harvesting device. The structural response characteristics of the asphalt pavement are not combined, and the structure is not reasonable, and the piezoelectric energy cannot be fully collected.

[0020] The present invention discloses a piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer. Figures 2 to 6As shown, when in use, by simulating the deformation mode of the asphalt pavement under different loads, the electric energy generated by the piezoelectric effect is extracted, thereby providing an environmentally friendly and sustainable energy collection solution for road facilities. The piezoelectric energy harvesting device 100 is a trapezoidal structure as a whole. The piezoelectric energy harvesting device 100 includes a compression zone 1, a shear zone 2 and a tension zone 3 arranged in sequence from top to bottom, wherein the compression zone 1 is used to withstand the pressure load generated by the vehicle 9 traveling on the asphalt pavement 200. The compression zone 1 is a rectangular structure, which can effectively disperse and evenly transmit the pressure from the asphalt pavement 200 or the wheel of the vehicle 9. The shear zone 2 is formed by the mortise and tenon connection of the upper tooth structure 20 and the lower tooth structure 21. The shear zone 2 connected by the mortise and tenon connection of the upper tooth structure 20 and the lower tooth structure 21 has a high shear deformation capacity, which can make the shear effect of the asphalt pavement 200 under the load of the vehicle 9 along the width direction of the piezoelectric energy harvesting device 100 (such as Figure 2 In the y direction as shown in the figure, a clamping block 22 is arranged between the upper toothed structure 20 and the lower toothed structure 21. The shape of the clamping block 22 can be adaptively set as needed. For example, the clamping block 22 is a rectangular structure, which can enhance the stability and durability of the structure. At the same time, it can also provide a reverse force during the deformation process, so that the shear zone 2 produces corresponding relative movement when the vehicle 9 passes by, thereby touching the piezoelectric work and generating electrical energy. The tensile zone 3 is an inverted arch structure, which can produce obvious bending deformation under the load of the vehicle 9. The tensile zone 3 of the inverted arch structure can not only effectively withstand the tensile force, but also enhance the overall compressive resistance of the device, thereby helping to enhance the tensile deformation of the piezoelectric energy capture device 100 and improve the efficiency of energy capture.

[0021] The upper tooth structure 20 includes an upper tooth end 201 and an upper tooth root 202, and the lower tooth structure 21 includes a lower tooth end 211 and a lower tooth root 212. In one example, the upper tooth end 201 and the upper tooth root 202 are an integral structure, and the lower tooth end 211 and the lower tooth root 212 are an integral structure. Figure 2 In the z direction as shown in the figure, there is a gap 23 between the upper tooth end 201 and the lower tooth root 212, as well as between the upper tooth root 202 and the lower tooth end 211. During use, the piezoelectric energy capture device 100 is embedded in the asphalt pavement 200. When the vehicle 9 travels on the asphalt pavement 200 and passes through the piezoelectric energy capture device 100, the upper tooth structure 20 and the lower tooth structure 21 can approach or move away from each other, so that the gap 23 increases and decreases, thereby inducing a stretching effect, thereby improving the efficiency of generating electric energy, so that the entire piezoelectric energy capture device 100 can achieve a comprehensive response to various mechanical effects (such as compression, shear and stretching) during the driving of the vehicle 9, and convert the vibration mechanical energy of the asphalt pavement 200 into electric energy through the force-to-electricity conversion characteristics of the piezoelectric material.

[0022] In some embodiments, continue to refer to Figures 2 to 6, each zone of the piezoelectric energy capture device 100 is piezoelectric ceramics, and the piezoelectric ceramics are piezoelectric ceramic lead titanate materials. The piezoelectric ceramic lead titanate materials have good piezoelectric properties and can generate a strong electric field when subjected to mechanical stress, thereby converting mechanical energy into electrical energy. Among them, the pressure zone 1 is composed of at least one piezoelectric ceramic stack, which can be adaptively set as needed. In one example, the pressure zone 1 uses two piezoelectric ceramics, and the two piezoelectric ceramics increase the overall deformation capacity and electrical energy output under pressure. The two piezoelectric ceramics use a stack structure that can effectively transfer the pressure from the asphalt pavement 200 or the wheel of the vehicle 9 to the piezoelectric ceramics. In another example, the upper tooth structure 20 and the lower tooth structure 21 are both made of piezoelectric ceramics, and the upper tooth structure 20 and the lower tooth structure 21 achieve a response to the shear force caused by the deformation of the asphalt pavement 200 through relative movement. In another example, when the vehicle 9 passes by the piezoelectric energy capture device 100, under the load of the vehicle 9, the upper toothed structure 20 can move up and down relative to the lower toothed structure 21, thereby inducing shear stress and generating electrical energy under the action of the shear force, so that the piezoelectric energy capture device 100 generates higher energy output when the vehicle 9 passes by.

[0023] At the same time, under the load of the vehicle 9, the clamp block 22 can maintain the overall stability of the upper tooth structure 20 and the lower tooth structure 21, and can also enhance the transmission of shear force. In one example, the clamp block 22 is a rectangular piezoelectric ceramic, which can effectively withstand and conduct the pressure change between the upper tooth structure 20 and the lower tooth structure 21, thereby further promoting the generation of piezoelectric effect and improving the energy conversion rate.

[0024] It should be noted that the vibration mode generated by the piezoelectric ceramic material in the present application when subjected to external stimulation is a 33 piezoelectric mode, and the stress direction in the 33 mode (such as Figure 2 The z direction shown in Figure 2 The z direction shown in FIG. 1 is parallel to the z direction, which facilitates the generation of more electrical energy.

[0025] In some embodiments, Figures 2 to 4 As shown, the size of the piezoelectric energy harvesting device 100 can be adaptively set as needed. In one example, the length, width and height of the piezoelectric energy harvesting device 100 are 150mm×150mm×150mm, the length can be modified according to actual conditions, the width can be designed according to the tire contact width direction of the vehicle 9, and the height matches the structure of the asphalt pavement 200, thereby ensuring sufficient bearing capacity and effective energy conversion space for the device, which is suitable for road facilities of different sizes. In one example, along the height direction of the piezoelectric energy harvesting device 100 (such as Figure 2In the z direction as shown in the figure), according to the strain analysis of the asphalt pavement 200, the height of the compression zone 1 is 20 mm, so that the piezoelectric ceramics can effectively respond to various pressures and deformations generated when the vehicle 9 passes by, while maintaining its strong mechanical properties and electrical energy conversion efficiency. The height of the tension zone 3 is 15 mm, so that the tension zone 3 can effectively withstand the tensile force when the vehicle 9 passes by, and convert it into electrical energy through the tensile effect of the piezoelectric ceramic material.

[0026] Along the height direction of the piezoelectric energy harvesting device 100 (eg Figure 2 In the z direction as shown in the figure, the height dimension of the gap 23 is 5-15mm. Under the load of the vehicle 9, the upper tooth structure 20 has space to move relative to the lower tooth structure 21, thereby generating shear deformation. For example, the height dimension of the gap 23 is 5mm, so that the upper tooth structure 20 has a smaller space to move relative to the lower tooth structure 21, which helps to improve the rigidity and stability of the overall structure of the piezoelectric energy capture device 100. For another example, the height dimension of the gap 23 is 15mm, so that the upper tooth structure 20 has a larger space to move relative to the lower tooth structure 21, thereby generating more electrical energy and achieving energy conversion efficiency.

[0027] In some embodiments, along the width direction of the piezoelectric energy harvesting device 100 (eg Figure 2 In the y direction shown in the figure), the width dimension of the upper tooth root 202 is 4-5mm, and the width dimension of the lower tooth root 212 is 3-15mm. In one example, along the width direction of the piezoelectric energy capture device 100, the width of the upper tooth root 202 is 4.76mm, the width of the lower tooth root 212 is 15mm, and the width of the clamp 22 is 7.14mm, so that the shear zone 2 can effectively respond to the shear force and compression force under the load of the vehicle 9, and the pressure and deformation generated by the vehicle 9 traveling on the asphalt pavement 200 triggers its piezoelectric effect. In another example, the width of the upper tooth root 202 is 4mm, the width of the lower tooth root 212 is 7.14mm, and the width of the clamp 22 is 7.14mm, thereby achieving energy conversion efficiency.

[0028] In some embodiments, Figure 2 and Figure 4 As shown, the tension zone 3 includes an inclined portion 30 and a horizontal portion 31. The inclined portion 30 is located on both sides of the horizontal portion 31 and forms an inverted ladder structure with the bottom of the shear zone 2. The inclined portion 30 is connected to the shear zone 2. The inclined portion 30 generates a more obvious bending deformation under the load of the vehicle 9. The extension direction of the horizontal portion 31 (as shown in FIG. Figure 4 y direction as shown in ) and the width direction of the sheared zone 2 (as shown in Figure 4 The horizontal portion 31 is parallel to the y direction (as shown in FIG. 1 ), and carries and distributes the load of the vehicle 9 to the entire piezoelectric energy capture device 100, and has a stabilizing effect.

[0029] In some embodiments, the size of the horizontal portion 31 can be adjusted according to the actual use situation, that is, the width of the horizontal portion 31 can be adjusted according to the changes in the load of the vehicle 9 or the road conditions, to ensure that the device can still maintain efficient energy collection and conversion capabilities under different conditions. The width of the horizontal portion 31 is 0-100mm along the width direction of the piezoelectric energy harvesting device 100. For example, when the width of the horizontal portion 31 is 100mm, it can withstand a larger horizontal tensile force, helping the piezoelectric energy harvesting device 100 to distribute the force more evenly, thereby avoiding structural damage caused by local stress concentration, and thus enabling the piezoelectric energy harvesting device 100 to work stably under a large load and provide a stable power output. For another example, the width of the horizontal portion 31 can be 50mm, and for another example, the width of the horizontal portion 31 can be 0mm, that is, the tensile zone 3 is a V-shaped structure, so that more voltage can be generated.

[0030] It should be noted that a circuit is provided on one side of the device, and the circuit adopts a two-stage energy interface step-down DC-DC conversion circuit, such as Figures 5 to 7 As shown, by adaptively adjusting the duty cycle, the load impedance is matched, thereby obtaining the maximum output efficiency and improving the energy collection efficiency of the circuit, so that the DC-DC conversion circuit can solve the problem of optimal load.

[0031] like Figures 5 to 14 As shown, the present application provides a method based on the mechanical behavior of asphalt pavement structure layer, comprising the following steps: Step 1: By establishing a three-dimensional finite element model of the asphalt asphalt pavement structure, applying a tire static load on it, and obtaining the mechanical characteristics of different layers of the asphalt asphalt pavement structure; By establishing a three-dimensional finite element model of the asphalt pavement structure, applying a static load of a vehicle 9 tire on it, dividing the structural layers according to the performance of the structural response of the asphalt pavement 200, and obtaining the mechanical behavior characteristics of different structural layers of the asphalt pavement 200, such as Figure 5 As shown, the structure of the asphalt pavement 200 is, from top to bottom, an upper layer 4, a middle layer 5, a lower layer 6, a base layer 7 and a soil base 8. A corresponding piezoelectric energy harvesting device 100 is set according to the structure of the asphalt pavement 200, and the geometric parameters of each layer are detected for subsequent mechanical analysis. The following table shows several parameters of the structure of each layer of the asphalt pavement 200: Step 2: Analyze and determine the mechanical characteristics of different layers of the asphalt asphalt pavement structure layer, as well as the corresponding stress-strain laws at different depths of the asphalt asphalt pavement structure layer; This application uses a three-dimensional finite element model to establish an asphalt pavement structure to analyze the mechanical properties and the corresponding stress-strain laws of each structural layer when tire loading is applied, such as Figures 5 to 11 As shown, Fig. 9 is the vertical stress extreme value distribution of asphalt pavement structure along the depth direction, Fig.10 is the variation law of the vertical shear stress extreme value with depth. In the figure, NC is the vertical shear stress on the inner side of the wheel, WC is the vertical shear stress on the outer side of the wheel, and Fig.11 The distribution of the extreme value of longitudinal tensile strain along the depth direction shows that within the depth range of 5 cm of the asphalt pavement, the extreme value of the vertical compressive stress is relatively close to 0.5 MPa. With the increase of depth, the extreme value of the vertical compressive stress decreases. At the bottom of the middle surface layer 5, the compressive stress is reduced by 50%, and the upper layer of 3 cm is the compression zone 1.

[0032] The shear stress on the outside reaches its maximum value at a depth of 6 cm, while the shear stress on the inside reaches its maximum value at a depth of 4 cm. Both maximum values ​​are 0.13 MPa. The upper part of the middle surface layer 5 is subject to the largest shear stress, and the area within 10 cm of the middle surface layer 5 is the shear zone 2.

[0033] The longitudinal tensile strain in the 200 structural layer of the asphalt pavement first decreases and then increases along the depth direction. The tensile strain below 5 cm decreases with increasing depth and reaches the maximum when approaching the bottom of the lower layer 6. The extreme value appears at z=15 cm. , the lower layer 6 will be subjected to a larger longitudinal tensile strain, and 3 cm of the lower layer 6 is the tensile zone 3.

[0034] Step 3: Based on the mechanical characteristics, design the piezoelectric energy harvesting device and conduct relevant experiments.

[0035] Among them, step 3 is divided into two steps. The first step is to establish the corresponding piezoelectric energy harvesting device 100 with a compression zone 1, a shear zone 2 and a tension zone 3 according to the mechanical characteristics, and calculate the shear deformation. Since the shear zone 2 will undergo shear deformation when subjected to shear force, the shear deformation formula of the shear zone 2 is as follows 1-1: (1-1) in, δ is the relative shear deformation (shear displacement), Q is the shear force acting on the device, L is the length of the device in the direction of shear force, G is the shear modulus of the material, A is the cross-sectional area of ​​the device.

[0036] In order to obtain the relative shear deformation parameters, the second step is to use the orthogonal experiment to optimize the piezoelectric energy harvesting device 100 to determine the geometric parameters required for the piezoelectric energy harvesting device 100. The orthogonal experiment is used to optimize the piezoelectric energy harvesting device 100. In this application, three factors and three levels are used to select the gap 23, the lower tooth root 212 and the horizontal part 31. A total of nine groups of experiments are required to make the voltage generated by the piezoelectric material the design principle, as shown in the following table: Factor Levels 1 2 3 Height of gap 5mm 10mm 15mm Width of lower tooth root 3.71mm 10mm 7.14mm Width of horizontal part 0 50mm 100mm After simulation using experimental finite element software, the following data were obtained: serial number Gap height (mm) Width of lower tooth root (mm) Width of horizontal part (mm) Voltage (V) 1 5 3.71 0 4770 2 5 10 100 5480 3 5 7.14 50 5880 4 10 3.71 100 4980 5 10 10 50 5200 6 10 7.14 0 6230 7 15 3.71 50 4420 8 15 10 0 6360 9 15 7.14 100 5350 Then, based on the above data, the range analysis and variance analysis are carried out, and the analysis table is as follows: The K value is calculated from the table. The formula for calculating the K value is as follows: (1-2) In the formula i is the level number, j is the column number, k ij is the voltage value of the level i in the jth column.

[0037] It should be noted that K ij avg For the j The average voltage of the level number i in the column, the range R j for .

[0038] like Fig.12 Shown are the mean values ​​of each factor level. The square sum formula is as follows 1-3:

[0039] In the formula is the voltage value of the test, is the total average value of the test voltage; By performing range and variance analysis on the above nine groups of data, it is found that the range value R of the width of the lower tooth root 212 is the largest, so this factor has the highest sensitivity and the largest F value, so the impact is the most significant. Therefore, the other two factors with weak sensitivity and insignificant are fixed, and the height of the gap 23 is fixed to 10mm, and the width of the horizontal part 31 is fixed to 0mm. A detailed analysis is performed on the most significant factors, and 5 parameters are designed for the width of the lower tooth root 212 to determine the optimal geometric structure. The data of the width and voltage of the lower tooth root 212 are subjected to mathematical analysis, and the relationship between the voltage and the width of the lower tooth root 212 is obtained by quadratic fitting, as shown in 1-4: Y=6956-381.09524X+32.30159 (1-4) In the formula Y is the voltage generated by the piezoelectric energy harvesting device, X is the width of the lower tooth root.

[0040] According to the above simulation and calculation, along the height direction of the piezoelectric energy harvesting device 100 (such as Figure 2The optimal geometric parameters are as follows: Figure 2 As shown, the height of the gap 23 is 10 mm, and the width direction of the piezoelectric energy harvesting device 100 (such as Figure 2 In the y direction shown in FIG, the width of the lower tooth root 212 is 15 mm, and the width of the horizontal portion 31 is 0 mm, so that more energy can be collected and the energy can be stored and utilized efficiently.

[0041] It should be noted that if Figure 1 The figure shows a conventional piezoelectric energy harvesting device 100', which is a stacked structure from top to bottom. In order to ensure the accuracy of the simulation data, the size of the voltage generated by the piezoelectric material is used as the design principle. It is placed in the asphalt pavement structure, and the comsol software is used to perform modeling calculations and comparative analysis of the structure. The piezoelectric energy harvesting device 100 in this application has the same width, depth and height as the conventional piezoelectric energy harvesting device 100'. Fig.13 The figure shows the potential display of the traditional piezoelectric energy harvesting device. Fig.14 The figure shows the potential display diagram of the piezoelectric energy harvesting device 100 in the present application. Through analysis by comsol software, it is found that the voltage generated by the piezoelectric energy harvesting device 100 in the present application is ten times that of the traditional piezoelectric energy harvesting device 100'.

[0042] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer, characterized in that: The piezoelectric energy capture device comprises a compression zone, a shear zone and a tension zone arranged in sequence from top to bottom, wherein the compression zone is a rectangular structure, the shear zone is formed by mortise and tenoning an upper toothed structure and a lower toothed structure, a clamping block is arranged between the upper toothed structure and the lower toothed structure along the width direction of the piezoelectric energy capture device, and the tension zone is an inverted arch structure; Among them, the upper tooth-like structure includes an upper tooth end and an upper tooth root, and the lower tooth-like structure includes a lower tooth end and a lower tooth root. Along the height direction of the piezoelectric energy capture device, there are gaps between the upper tooth end and the lower tooth root, and between the upper tooth root and the lower tooth end.

2. A piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer according to claim 1, characterized in that: Each area of ​​the piezoelectric energy capture device is a piezoelectric ceramic, and the piezoelectric ceramic is a piezoelectric ceramic lead titanate material, wherein the pressure-bearing area is composed of at least one stack of the piezoelectric ceramic, and the clamping block is a rectangular piezoelectric ceramic structure.

3. A piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer according to claim 2, characterized in that: The length, width and height dimensions of the piezoelectric energy harvesting device are 150mm×150mm×150mm, wherein along the height direction of the piezoelectric energy harvesting device, the height of the compression zone is 20mm, the height of the tension zone is 15mm, and the height dimension of the gap is 5-15mm.

4. The piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer according to claim 1 is characterized in that: Along the width direction of the piezoelectric energy harvesting device, the width dimension of the upper tooth root is 4-5 mm, and the width dimension of the lower tooth root is 3-15 mm.

5. The piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer according to claim 1 is characterized in that: The tension zone includes an inclined portion and a horizontal portion, the inclined portion is connected to the shear zone, and an extending direction of the horizontal portion is parallel to a width direction of the shear zone.

6. A piezoelectric energy harvesting device based on the mechanical behavior of asphalt pavement structure layer according to claim 5, characterized in that: Along the width direction of the piezoelectric energy harvesting device, the width dimension of the horizontal portion is 0-100 mm.

7. A method based on the mechanical behavior of asphalt pavement structure layer, characterized in that: The steps include: Step 1: By establishing a three-dimensional finite element model of the asphalt asphalt pavement structure, applying a tire static load on it, and obtaining the mechanical characteristics of different layers of the asphalt asphalt pavement structure; Step 2: Analyze and determine the mechanical characteristics of different layers of the asphalt asphalt pavement structure layer, as well as the corresponding stress-strain laws at different depths of the asphalt asphalt pavement structure layer; Step 3: Based on the mechanical characteristics, design a piezoelectric energy harvesting device and conduct relevant experiments.

8. The method based on the mechanical behavior of asphalt pavement structure layer according to claim 7 is characterized in that: Step 3 includes the following steps: Step 31: According to the mechanical characteristics, the corresponding piezoelectric energy harvesting device having a compression zone, a shear zone and a tension zone is established, and the shear deformation is calculated. Since the shear zone will undergo shear deformation when subjected to shear force, the shear deformation formula of the shear zone is: ； in, is the relative shear deformation (shear displacement), is the shear force acting on the device, L is the length of the device in the direction of shear force, G is the shear modulus of the material, A is the cross-sectional area of ​​the device; Step 32: Optimize the piezoelectric energy harvesting device using orthogonal experiments to determine the solution for the geometric parameters required for the piezoelectric energy harvesting device.

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