A broadband energy harvesting device and system for an arch bridge structure

Abstract

The application relates to the technical field of energy collection, and particularly provides a wide-frequency energy collection device and system of an arch bridge structure. The device comprises a bridge top section, bridge arch sections symmetrically arranged at two ends of the bridge top section, a substrate layer fixedly arranged at one end of the bridge arch section away from the bridge top section, one of the bridge arch sections and the substrate layer is arranged on each side, the device is symmetric about a central axis, the substrate layer comprises, from top to bottom, a fin layer, a shear electrode and a substrate; the arch section comprises, from outside to inside, a first structure layer, a first damping layer and a second structure layer, the first damping layer has a thickness gradient along the length direction of the bridge arch section, the thickness of the first damping layer is large on the side close to the bridge top section and is small on the side close to the substrate layer. The first damping layer bears shearing and improves equivalent loss, reduces a quality factor and widens a single peak; the limited shearing stiffness of the first damping layer introduces interlayer dislocation and weak coupling of a main mode, thereby splitting near neighbors; the thickness is thick on the top and thin on the bottom, forming a soft top and a hard bottom, which strengthens splitting and stably transmits force, so that double peaks are filled and flattened into a platform by the damping, and the frequency band is widened.

Description

Technical Field

[0001] This application relates to the field of energy harvesting technology, and more specifically, to a broadband energy harvesting device and system with an arch bridge structure. Background Technology

[0002] Energy harvesting devices convert weak mechanical, thermal, optical, and radio frequency energy from the environment into usable electrical energy to replace or extend battery life, reduce maintenance costs, and achieve long-term self-powered operation. They have broad application prospects in fields such as industrial equipment condition monitoring sensors, health monitoring nodes for civil and electromechanical structures such as bridges, railways, and wind turbines, passive positioning tags in logistics and warehousing, wearable and implantable medical sensors, environmental monitoring terminals deployed in the field, and low-power nodes for the Internet of Things.

[0003] Vibration energy exhibits complex frequency components that drift over time. Examples include the fundamental frequency and higher harmonics of pumps / motors at different operating speeds, the broad-spectrum excitation generated by vehicles crossing bridges, the random components of wind-induced and human-induced vibrations, and frequency drift and dispersion caused by temperature, load, and aging. Actual measured vibration spectra often exhibit multi-peak, broad-spectrum, and time-varying characteristics, with energy not stably concentrated at a single narrow frequency point. This imposes a broadband requirement on energy harvesting, meaning the device must maintain effective electromechanical coupling and stable output across a wide frequency range, rather than being only briefly efficient near a single resonance point.

[0004] Piezoelectric cantilever beam resonant energy harvesters have a high market share. As narrow-band linear resonators, their effective output is mainly concentrated near the first-order natural frequency. When the ambient frequency deviates from this point, electromechanical coupling and output power decrease sharply. To improve detuning, common approaches include paralleling / parallelizing multiple harvesters with different tuning frequencies or using tunable mechanisms. However, the former increases size, weight, and cost, and introduces spatial and circuit coupling between channels; the latter requires active tuning or complex mechanisms, limiting reliability and energy efficiency. Similarly, while nonlinear magnetic attraction / limiting schemes can extend the frequency band, they often introduce uncontrollable multistable states and jumps, resulting in large output fluctuations and poor reproducibility. Overall, traditional single-beam / single-mode structures can only cover a narrow frequency band and are insufficient to handle the multi-peak, time-varying vibration spectrum in the field. In engineering, stacking multi-frequency devices to improve coverage leads to increased cost, space constraints, and increased difficulty in system-level power management, still failing to achieve a flat and stable energy output over a wide frequency range. In other words, existing piezoelectric cantilever beam resonant energy harvesters cannot meet practical needs.

[0005] In summary, existing energy harvesting devices have narrow response bands, resulting in low energy harvesting efficiency and failing to meet practical needs in energy harvesting. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of the prior art by providing a broadband energy harvesting device and system for an arch bridge structure, thereby solving the problem of low energy harvesting efficiency caused by the narrow response band of existing energy harvesting devices.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This application provides a broadband energy harvesting device for an arch bridge structure. The device includes a bridge top section, arch sections symmetrically arranged at both ends of the bridge top section, and a substrate layer fixedly arranged at the end of the arch section away from the bridge top section. One of each is arranged on both sides of the arch section and the substrate layer, and is symmetrical about the central axis of the device. The substrate layer includes, from top to bottom, a fin layer, a shear electrode, and a substrate. The arch section includes, from the outside to the inside, a first structural layer, a first damping layer, and a second structural layer. The first damping layer has a thickness gradient along the length of the arch section: the first damping layer is thicker on the side closer to the bridge top section and thinner on the side closer to the substrate layer.

[0008] To achieve a wideband response, this application sets the bridge arch segment as an outer first structural layer and an inner second structural layer, with a first damping layer placed between the first and second structural layers. The first damping layer is a viscoelastic layer between the two structural layers. Under external vibration, a small relative movement occurs between the bridge arch segment and the substrate layer fixed on the vibration surface, causing differential displacement of the two structural layers along the interface direction, thereby forming in-plane shear deformation within the damping layer. In this way, on the one hand, the first damping layer has viscoelastic properties, and the deformation energy is distributed to the first damping layer in the form of shear, increasing the proportion of shear energy borne by the first damping layer, thereby improving the modal equivalent loss factor, reducing the quality factor, and broadening the sharp single-peak response; on the other hand, the finite shear stiffness of the first damping layer forms a sandwich structure of interlayer shear springs between the outer "first structural layer, damping layer, and inner second structural layer". The device also has additional internal degrees of freedom dominated by interlayer relative displacement, forming a weak coupling with the overall follower motion, resulting in two similar eigensols in the frequency domain, thus the resonance peak exhibits a double peak. With the combined effect of damping, the response between the two peaks is flattened into a plateau, enabling the device to achieve stable output over a wider frequency range.

[0009] The thickness of the first damping layer in this application gradually decreases from top to bottom, forming an interlaminar shear stiffness and loss distribution coupled along the length and thickness directions. In the thicker upper region, the first damping layer bears a higher proportion of in-plane shear deformation under the action of interlaminar differential displacement, resulting in a larger thickness and lower interlaminar shear stiffness. Where K represents the interlayer shear stiffness, G is the energy storage shear modulus of the first damping layer, A is the effective shear area, and t is the thickness), the coupling is more flexible, improving the local modal equivalent loss factor, reducing the quality factor, suppressing single peaks, and strengthening the weak coupling of relative displacement degrees of freedom to the master and follower motions, thus promoting the splitting of neighboring peaks. The gradually decreasing thickness of the lower region maintains a larger interlayer shear stiffness and a more uniform load distribution, avoiding drift and output jitter caused by excessively soft coupling, and causing the two neighboring peaks to be flattened into a plateau under the damping effect. This achieves the effects of increasing loss and coupling peak splitting in the upper part, and maintaining force transmission and steady-state output in the lower part, improving the response frequency range of the device without sacrificing electrical stability.

[0010] In application, two substrates are bonded or fastened to the surface to be vibrated. During energy collection, due to inertia, the bridge arch section experiences slight relative motion with respect to the substrate fixed to the vibrating surface. This relative motion causes slight bending and interlayer shearing along the length of the arch section. Stress and energy transfer occur between the first damping layer of the arch section and the structural layers on both sides. Subsequently, the wing layer at the end of the arch section evenly distributes the load to the shear electrode below, subjecting the electrode to a stress field dominated by in-plane shear. The shear electrode converts the shear strain caused by vibration into an alternating current signal based on the piezoelectric effect. The outputs of the two symmetrical electrodes are rectified and combined to the energy storage capacitor to charge the battery, completing the collection and storage of vibration energy into electrical energy. Throughout the process, the first damping layer simultaneously provides energy dissipation and coupling tuning, enabling the device to maintain stable electromechanical output under broadband vibration conditions.

[0011] Furthermore, the thickness of the first damping layer is 0.2-0.4 times the sum of the thicknesses of the first and second structural layers, and not less than 0.1 mm. At this ratio, the first damping layer can withstand sufficient in-plane shear deformation within the operating frequency band, increasing its shear energy proportion, raising the equivalent loss factor, and lowering the quality factor, thereby broadening the single-peak response. According to... This thickness allows the interlayer shear stiffness to fall within a moderate range, and the additional relative displacement degrees of freedom formed by the structural layers on both sides produce a nearest-neighbor split in the frequency domain, which facilitates the formation of double peaks and intermediate plateaus.

[0012] Furthermore, the surfaces of the first and second structural layers on both sides of the first damping layer are serrated, with the two sides of the first damping layer also serrated. The serrated surface decomposes the relative displacement along the interface direction into two components: tangential slip and normal compression. The meshing of the tooth surfaces causes the shear force to be transmitted along a broken path. Compared with a straight interface, the equivalent shear path is lengthened, the geometric tortuosity coefficient increases, the interlayer shear stiffness decreases, the proportion of shear energy borne by the first damping layer increases, the equivalent loss factor increases, the quality factor decreases, and the originally sharp single peak is broadened. At the same time, the inclined surface compression and finite shear stiffness generate additional internal degrees of freedom between the layers, mainly interlayer relative displacement, and form a weak coupling with the overall follower motion, splitting into two similar eigensols in the frequency domain, resulting in a double peak. Under the loss effect of the first damping layer, the valley between the two peaks is filled into a platform, achieving a flatter broadband response.

[0013] Furthermore, the serrated teeth are along the length direction; the serrated groove openings are normal in the thickness direction. The teeth are arranged along the length to ensure that the main shear force is transmitted along the interface direction. The vertical openings of the grooves form an in-plane zigzag interlock, which increases the path tortuosity and local coupling strength without changing the overall boundary conditions, so that the equivalent interlayer shear stiffness is reduced to a range that is conducive to the splitting of neighboring layers. Combined with the viscoelastic properties of the first damping layer, it can further suppress the peaks and fill the valleys between the two peaks to obtain a more stable broadband plateau.

[0014] Furthermore, the thickness of the first structural layer is greater than that of the second structural layer. The greater thickness of the first structural layer creates an asymmetrical structure, resulting in a separable numerical difference in equivalent stiffness and participating mass between the overall kinematic degrees of freedom of the two layers with nearly unidirectional displacement and the interlayer relative displacement degrees of freedom of the two layers with small differential displacements along the interface. This naturally separates the eigensols of the device's resonant frequency into two adjacent branches. Due to the greater thickness of the first structural layer, the load diffusion at the interface is more complete, peak stress and local abrupt changes are suppressed, and the first damping layer participates in controlled shear over a larger range, resulting in distinguishable peaks without merging. The equivalent loss of the first damping layer is flattened between the two peaks, creating a plateau, thus improving the average output under deharmonic conditions and making the output more stable.

[0015] Furthermore, the outer thickness of the wing layer is greater than the inner thickness, and the lower surface of the wing layer is planar. As a load-sharing component, the outer thickness and inner thinness of the wing layer result in higher in-plane stiffness near the outer side, enabling the force transmitted from the end of the bridge arch section to be rapidly spread within the wing layer and uniformly transferred along the plane to the shear electrode below. The planar lower surface ensures uniform thickness of the adhesive layer and contact stress, avoiding local high-gradient stress and point force transmission. In this way, the electrode mainly bears in-plane shear rather than local peeling, and signal jitter and random side peaks are suppressed. At the same time, this configuration can generate a larger shear force on the shear electrode. Specifically, the upper surface of the wing layer is an inclined surface with a higher outer surface and a lower inner surface. The force of the bridge arch section is applied approximately perpendicular to this inclined surface. The components of the force in the tangential and normal directions of the inclined surface are projected onto the horizontal direction and superimposed, resulting in a larger shear force. This creates a larger in-plane tangential load at the shear electrode, preferentially stimulating the shear response of the electrode. As a result, under the same excitation, the electrode obtains higher and more uniform shear stress, local peeling and indentation are suppressed, and current pulsation is reduced.

[0016] Furthermore, a second damping layer is disposed between the wing layer and the shear electrode. This second damping layer possesses viscoelastic properties, ensuring uniform load distribution within the electrode surface and limiting micro-slippage. It suppresses high-order local responses and pulsations at the interface between the wing layer and the shear electrode, reducing current ripple and depolarization risks. The second damping layer does not introduce new master degrees of freedom, nor does it weaken the interlayer coupling and nearest-neighbor splitting mechanisms dominated by the first damping layer. While maintaining the plateau shape and output stability, it improves device consistency and lifespan, complementing the main broadband mechanism.

[0017] Furthermore, the Young's modulus of the first structural layer material is greater than that of the second structural layer material. This creates an outer hard and inner relatively soft distribution, resulting in separable differences in equivalent stiffness and energy distribution between the overall servo motion and the interlayer relative slip motion. Under finite shear coupling, this naturally forms distinguishable nearest-neighbor splits and constitutes a double peak. At the same time, the high modulus of the outer layer enhances load diffusion and interface support, reduces peak stress and peel sensitivity, and allows the first damping layer to participate in controlled shearing rather than excessive softening within the target frequency band, ultimately achieving bandwidth broadening while maintaining smooth and stable electrical output.

[0018] Furthermore, the device also includes a mass block, which is fixedly mounted on the bridge top section. The mass block can increase the inertia of the bridge top section, generating a larger relative displacement and velocity under the same substrate acceleration, thus intensifying the relative motion of the bridge top section with respect to the substrate, improving the interlayer shear within the bridge arch section and the effective participation of the first damping layer, and enabling the electrodes to obtain higher in-plane shear strain.

[0019] This application also proposes a broadband energy harvesting system for an arch bridge structure. The system includes the aforementioned broadband energy harvesting device for the arch bridge structure. Both shear electrodes are equipped with current output leads, which are connected to a rectifier circuit. The rectifier circuit is connected to an energy storage capacitor, and then to a battery for charging. Each of the two shear electrodes has a lead connected to a rectifier circuit, the rectifier end of which is connected to the energy storage capacitor, and then to the battery for charging. The two AC signals are rectified and combined, first storing and smoothing energy on the energy storage capacitor side, avoiding voltage clamping and electromechanical coupling mismatch between the battery and the AC side, thereby efficiently and stably converting and storing vibration energy in the battery under broadband operating conditions.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows: This application incorporates a first damping layer between the outer first structural layer and the inner second structural layer. Under external vibration, the bridge top section and the substrate layer fixed to the vibration surface undergo slight relative movement, causing differential displacement of the two structural layers along the interface. The first damping layer bears the in-plane shear deformation. Its viscoelastic properties allow more deformation energy to be distributed to the first damping layer, increasing the equivalent loss, decreasing the quality factor, and broadening the sharp resonance peak. Simultaneously, the finite shear stiffness of the damping layer and the two structural layers form an interlayer shear spring structure. In addition to overall homing, it introduces internal degrees of freedom dominated by interlayer relative displacement, forming a weak coupling with the principal degrees of freedom. This results in a nearest-neighbor split in the frequency domain, producing a double peak, which is then filled in between, broadening the response frequency.

[0021] Furthermore, the thickness of the first damping layer gradually decreases from top to bottom, forming an interlayer shear stiffness and loss distribution that is softer at the top and harder at the bottom: the thicker upper part makes the coupling more flexible and the damping participation higher, strengthening splitting and suppressing single spikes; the thinner lower part maintains greater shear stiffness and more uniform load distribution, avoiding drift and output jitter caused by excessive softness, and causing the two nearest-neighbor peaks to be flattened into a plateau under the action of damping. Thus, the effective response bandwidth of the device is broadened without sacrificing electrical stability. Attached Figure Description

[0022] Figure 1 A schematic diagram of a broadband energy harvesting device for an arch bridge structure provided by this utility model; Figure 2 A schematic diagram of the first structural layer, the first damping layer, and the second structural layer of a broadband energy harvesting device with an arch bridge structure provided by this utility model; Figure 3 A schematic diagram of the sawtooth structure in another broadband energy harvesting device with an arch bridge structure provided by this utility model; Figure 4 A schematic diagram of the wing layer, shear electrode, and second damping layer of another broadband energy harvesting device with an arch bridge structure provided by this utility model; Figure 5A schematic diagram of a broadband energy harvesting system for an arch bridge structure provided by this utility model.

[0023] Icons: 1-Bridge top section; 2-Bridge arch section; 21-First structural layer; 22-First damping layer; 23-Second structural layer; 3-Substrate layer; 31-Wing layer; 32-Shear electrode; 33-Substrate; 34-Second damping layer. Detailed Implementation

[0024] To make the implementation process of this utility model clearer, a detailed description will be provided below in conjunction with the accompanying drawings.

[0025] Example 1: This application provides a broadband energy harvesting device for an arch bridge structure, such as... Figure 1 As shown, the device includes a bridge top section 1, bridge arch sections 2 symmetrically arranged at both ends of the bridge top section 1, and a substrate layer 3 fixedly disposed at the end of the bridge arch section 2 away from the bridge top section 1. One bridge arch section 2 and one substrate layer 3 are disposed on each side, symmetrical about the central axis of the device. Central axis symmetry ensures balanced mass and stiffness distribution, suppressing lateral sway and torsion; the load is more uniform and phase-consistent on the two electrodes, facilitating parallel / serial and rectification merging; it also counteracts secondary modes caused by processing and temperature drift deviations, improving platform stability and reliability. The substrate 33 is a straight flat plate; the material of the substrate 33 is aluminum alloy or titanium alloy, which is low-cost and easy to process. The planes containing the bridge top section 1 and the two substrate layers 3 are parallel and skew-plane, both in the horizontal direction. The arch section 2 is an inclined flat plate. The angle between the arch section 2 and the inner side of the substrate layer 3 is 30°-40°. This angle range can achieve a balance between the normal and tangential components. Specifically, the in-plane shear component is large, which facilitates the activation of the interlayer relative displacement degree of freedom. This allows the first damping layer 22 to participate in controlled shear, reducing the quality factor and forming a nearest-neighbor split. The double peaks are easily damped and flattened into a plateau, thereby widening the effective frequency band. If the angle is too small, the shear is insufficient; if the angle is too large, the normal bending and end stress increase, and the plateau narrows.

[0026] The substrate layer 3 comprises, from top to bottom, a fin layer 31, a shear electrode 32, and a substrate 33. The fin layer 31 is used to uniformly spread the force transmitted from the arch segment 2 within the plane of the shear electrode 32. Specifically, the fin layer 31 diffuses the concentrated force transmitted from the arch segment 2 into uniform in-plane shear within its plane, reducing the normal component and local bending, so that the shear electrode 32 mainly bears shear rather than indentation and bending. This reduces the interface peak stress and the risk of peeling, suppresses microcracks and depolarization of brittle single crystals, and avoids current jitter caused by the mutual cancellation of positive and negative shear regions. At the same time, the fin layer 31 provides consistent stress field boundary conditions for the shear electrode 32, making the outputs of the two arms accumulate in phase, reducing the frequency response subpeaks, and making the plateau more stable. Combined with a thin and moderate adhesive layer, it can filter out high-order local modes, improving the usable bandwidth and output stability at the expense of peak value. The fin layer 31 is made of Al6061-T6 or stainless steel 304, with a thickness of 0.4-1.2 mm; its lower surface is planar to improve load sharing and reliability. The shear electrode 32 is responsible for electromechanical conversion, transforming shear stress into current output. The shear electrode 32 can be a high-shear-coefficient single-crystal PMN-PT, PZT-5H, LiNbO3, or a PIN-PMN-PT single-crystal electrode grown in the

[001] direction, with a thickness of 0.2-0.5 mm. The substrate 33 is made of stainless steel or alumina ceramic, with a thickness of 0.5-2.0 mm, and is used to provide support for the device.

[0027] The arch section 2 is bonded and fixedly connected to the wing layer 31 and the top section 1, with no macroscopic relative motion. This ensures that the force of the arch section 2 is uniformly converted into in-plane shear through the wing layer 31, stabilizing the stress field and electrical output, and avoiding random contact, reverse shear, and power burrs caused by relative slippage. On the other hand, it protects the brittle shear single crystal and interface, preventing peeling, indentation, depolarization, and fatigue failure.

[0028] The bridge arch segment 2, from the outside in, includes a first structural layer 21, a first damping layer 22, and a second structural layer 23. All three layers are bonded and fixedly connected to the bridge top segment 1 and the wing layer 31. Specifically, the materials of the first structural layer 21 and the second structural layer 23 can be one of aluminum alloy, titanium alloy, monocrystalline silicon, polyimide, silicone rubber, PDMS, or polyurethane. The materials of the first structural layer 21 and the second structural layer 23 can be the same or different. The material of the first damping layer 22 is acrylic, polyurethane, butyl / compartment nitrile rubber, or silicone rubber; its energy storage shear modulus is 0.3-3 MPa, and its loss factor is 0.2-0.9. The height of the first damping layer 22 is the same as that of the first structural layer 21 and the second structural layer 23, and its width is perpendicular to the [missing information - likely a measurement or measurement]. Figure 1The length of the plane shown is the same as that of the first structural layer 21. The thickness of the first damping layer 22 is 0.2-0.4 times the sum of the thicknesses of the first structural layer 21 and the second structural layer 23, and not less than 0.1 mm. The first damping layer 22 has a thickness gradient along the length of the bridge arch section 2: the first damping layer 22 is thicker on the side closer to the bridge top section 1 and thinner on the side closer to the substrate layer 3. The thickness variation is uniform along both sides of the first damping layer 22, as shown... Figure 2 As shown, the first damping layer 22 exhibits a symmetrical gradient that converges equidistantly along its length, meaning that the interfaces on both sides yield equally. This ensures that the variation in interlayer shear stiffness is distributed only along the length and does not introduce bias in the width direction. This avoids lateral bending-torsional coupling and sub-modes caused by a unilateral wedge shape, resulting in more in-phase output and a flatter plateau for both arms. The symmetrical stress gradients at the two interfaces reduce peeling and fatigue hot spots, improving reliability. Compared to an asymmetric wedge that only thickens on one side, a symmetrical gradient is more conducive to obtaining nearest-neighbor splitting and a flat plateau, thereby broadening the device's response frequency.

[0029] Furthermore, to increase the degree of deformation caused by energy harvesting, the device also includes a mass block, which is fixedly mounted on the bridge crown section 1. The mass block is made of stainless steel or tungsten. Generally, it is positioned in the middle of the upper surface of the bridge crown section 1. This maintains the symmetry of the system's mass and stiffness around the central axis. Specifically, on the one hand, the forces and displacements of the two bridge arch sections 2 are in phase, avoiding torsion and local stress peaks caused by offset. On the other hand, it preferentially couples the symmetrical principal modes, facilitating the formation of stable internal resonances between the second / third order frequencies and the first order, and the nearby double peaks can be distinguished and flattened into a plateau by damping. Compared to the offset arrangement, the central arrangement reduces erratic peaks and temperature drift sensitivity, making the broadband response more controllable and stable.

[0030] Example 2: Based on Example 1, the response frequency is further broadened. For example... Figure 3 As shown, the surfaces of the first structural layer 21 and the second structural layer 23 on both sides of the first damping layer 22 are serrated. The serrated surfaces of the first damping layer 22 can be fabricated using micro-milling and laser etching techniques. The serrated teeth are along the length direction; the serrated groove openings are normal in the thickness direction. Specifically, the tooth angle is 30-45°, and the tooth height gradually increases from bottom to top. Figure 3 As shown. Furthermore, the serrated region is only located in the middle length section, with a section reserved at each end near the bridge top section 1 and the substrate layer 3. The length of the serrated region is 0.8 times the length of the bridge arch section 2. This avoids the high bending moment and assembly area at the root and ends, reducing root stress and the risk of interface delamination, maintaining continuous boundary bonding and smooth load transition; simultaneously, it reduces end-edge stress concentration and the impact of process tolerances, making interlayer shear coupling more controllable and the broadband platform more stable.

[0031] Example 3: Based on Example 1, the materials and thicknesses of the first structural layer 21 and the second structural layer 23 are different. The Young's modulus of the material of the first structural layer 21 is greater than that of the material of the second structural layer 23; the Young's modulus of the first structural layer 21 is 50-200 GPa; specifically, it is one of aluminum alloy, titanium alloy, or single crystal silicon. The Young's modulus of the second structural layer 23 is 0.1-100 MPa (elastomer range), specifically, it is one of silicone rubber, PDMS, or polyurethane. Furthermore, the thickness of the first structural layer 21 is greater than the thickness of the second structural layer 23; the thickness of the first structural layer 21 is 1.3-1.5 times the thickness of the second structural layer 23, forming a slight asymmetry. In this way, on the one hand, the equivalent stiffness of the two degrees of freedom, namely the overall follow-up motion and the interlayer relative slip motion, can be separated, making it easier for neighboring splits to occur and distinguishable, thus avoiding peak merging when it is too symmetrical; on the other hand, the slightly thicker outer layer improves load diffusion and reduces the peak stress at the interface, so that the first damping layer 22 participates in controlled shear within the target frequency band, without the overall stiffness and narrowing of the platform caused by the outer layer being too thick.

[0032] Example 4: Based on Example 1, such as Figure 4 As shown, the outer thickness of the wing layer 31 is greater than the inner thickness of the wing layer 31, and the lower surface of the wing layer 31 is planar. A second damping layer 34 is disposed between the wing layer 31 and the shear electrode 32. The thickness of the second damping layer 34 is 30-100 μm, the shear storage modulus is 5-50 MPa, the loss factor is 0.1-0.3, and the material of the second damping layer 34 is cyanate ester or bismaleimide. The shear storage modulus of the second damping layer 34 is greater than that of the first damping layer 22, that is, compared with the first damping layer 22, the second damping layer 34 is stiffer and has moderate loss. The function of the second damping layer 34 is to uniformly transmit shear and filter the interface. Specifically, it spreads the load collected by the wing layer 31 of the bridge arch segment 2 with equal thickness and equivalent effect within the electrode plane, suppresses high-order local modes and current spikes at the interface, reduces the risk of depolarization and stripping, and maintains output smoothness and consistency. With a higher shear storage modulus and a thinner thickness, it can avoid forming a new soft spring degree of freedom on the side of the shear electrode 32, leaving the main displacement and energy distribution to the first damping layer 22 and the main body of the shear electrode 32, thus not interfering with the mechanism of equivalent damping increase, interlayer coupling peak splitting, and flat-top broadband dominated by the first damping layer 22.

[0033] Example 5: This application also proposes a broadband energy harvesting system with an arch bridge structure. This system includes the aforementioned broadband energy harvesting device with an arch bridge structure. Both shear electrodes 32 are equipped with current output leads, which are connected to a rectifier circuit. The rectifier circuit is connected to an energy storage capacitor, and then to a battery for charging. The battery can be one, two, or even multiple, depending on the amount of energy to be harvested and the battery capacity. Figure 5 As shown. Specifically, each shear electrode 32 outputs a signal via a lead wire, using shielded twisted-pair cable or tinned copper wire with a diameter of approximately 0.2-0.3 mm. 2 To reduce noise interference, both signals first enter a rectifier circuit, such as the LTC3588-1 or MAXM17532, which has low static loss and a startup voltage below 0.8V, making it suitable for piezoelectric energy input. After rectification, an energy storage capacitor is connected. This capacitor can be a low-leakage, high-reliability electrolytic or tantalum capacitor with a capacitance range of 47-220μF and a rated withstand voltage greater than twice the input peak voltage; a recommended model is EEFGX0J101R. The battery can be a 3.7V rechargeable lithium battery or a solid-state thin-film battery, with a capacity of 10-100mAh selected according to application requirements. Those skilled in the art can configure a charging management module as needed.

[0034] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A broadband energy harvesting device with an arch bridge structure, the device comprising a bridge top section, arch sections symmetrically arranged at both ends of the bridge top section, and a substrate layer fixedly disposed at the end of the arch section away from the bridge top section, wherein one arch section and one substrate layer are disposed on each side, symmetrical about the central axis of the device, and the substrate layer comprises, from top to bottom, a fin layer, a shear electrode, and a substrate; characterized in that, The bridge arch section includes a first structural layer, a first damping layer, and a second structural layer from the outside to the inside. The first damping layer has a thickness gradient along the length of the bridge arch section: the first damping layer is thicker on the side closer to the top of the bridge and thinner on the side closer to the substrate layer.

2. The broadband energy harvesting device for an arch bridge structure according to claim 1, characterized in that, The thickness of the first damping layer is 0.2-0.4 times the sum of the thicknesses of the first structural layer and the second structural layer, and is not less than 0.1 mm.

3. The broadband energy harvesting device for an arch bridge structure according to claim 2, characterized in that, The surfaces of the first structural layer and the second structural layer on both sides of the first damping layer are serrated, and the two sides of the first damping layer are serrated.

4. The broadband energy harvesting device for an arch bridge structure according to claim 3, characterized in that, The serrated teeth are along the length direction; the serrated groove openings are normal in the thickness direction.

5. The broadband energy harvesting device for an arch bridge structure according to claim 4, characterized in that, The thickness of the first structural layer is greater than the thickness of the second structural layer.

6. The broadband energy harvesting device for an arch bridge structure according to claim 5, characterized in that, The thickness of the outer side of the wing layer is greater than the thickness of the inner side of the wing layer, and the lower surface of the wing layer is a plane.

7. The broadband energy harvesting device for an arch bridge structure according to claim 6, characterized in that, A second damping layer is disposed between the wing layer and the shear electrode.

8. The broadband energy harvesting device for an arch bridge structure according to claim 7, characterized in that, The Young's modulus of the first structural layer material is greater than that of the second structural layer material.

9. The broadband energy harvesting device for an arch bridge structure according to claim 8, characterized in that, The device also includes a mass block, which is fixedly mounted on the top section of the bridge.

10. A broadband energy harvesting system for an arch bridge structure, characterized in that, The system includes a broadband energy harvesting device with an arch bridge structure as described in any one of claims 1-9. Both shear electrodes are provided with current output leads, which are connected to a rectifier circuit. The rectifier circuit is connected to an energy storage capacitor and then to a battery to charge the battery.

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