Quasi-zero stiffness metamaterial vibration reduction mounting structure of underwater vehicle hydrophone

Abstract

The invention discloses a quasi-zero stiffness metamaterial vibration reduction mounting structure of an underwater vehicle hydrophone, which belongs to the technical field of underwater vehicles, and comprises an oil seal end cover mounted at the front end of a front fairing of an underwater vehicle, a mounting rack fixed at the front end part of the oil seal end cover, and two quasi-zero stiffness vibration reduction components arranged in front of and behind the mounting rack, the outer side parts of the quasi-zero-stiffness vibration reduction components are connected with the mounting frame, concave parts for clamping the end parts of the hydrophone are formed in the middle parts of the quasi-zero-stiffness vibration reduction components, and a mounting space for arranging the hydrophone is formed between the two quasi-zero-stiffness vibration reduction components; and the two ends of the hydrophone are respectively clamped and clamped in the concave parts of the two quasi-zero stiffness damping components. According to the quasi-zero-stiffness metamaterial damping device, through conformal design, vibration attenuation, structure optimization and energy-saving effects, an efficient, stable and low-noise hydrophone installation solution is provided for an autonomous underwater vehicle, and the performance of the quasi-zero-stiffness metamaterial damping device in underwater detection and signal acquisition is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater vehicles, and in particular relates to a quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone. Background Art

[0002] Autonomous underwater vehicles are widely used in the fields of hydroacoustic detection, microbial sampling, mineral development and environmental monitoring. As a typical acoustic sensor, hydrophones are often carried on autonomous underwater vehicles to perform hydroacoustic detection tasks. However, traditional hydrophones and autonomous underwater vehicles usually adopt a rigid connection method, which causes the vibration and noise of the functional components at the rear end of the vehicle to be transmitted to the front end through the shell during underwater operations, affecting the operation of the hydrophone. The frequency range of these vibrations is often close to the operating frequency band of the hydrophone, which seriously interferes with signal acquisition and reduces the sensitivity and accuracy of sampling. Therefore, it is particularly important to study the vibration and noise reduction structure of the hydrophone to improve its detection performance in complex underwater environments.

[0003] The vibration and noise reduction technologies currently used in hydrophones are divided into two categories: active noise reduction and passive noise reduction, but they each have some shortcomings in practice.

[0004] First of all, active noise reduction technology cancels out noise by sending a signal with an opposite phase to the vibration noise, thereby achieving a noise reduction effect. For example, invention patent CN110632649A proposes a vibration noise cancellation method for fiber-optic hydrophones. By installing a time-delay interferometer near the hydrophone and connecting the output fiber of the interferometer to the input fiber of the hydrophone, the vibration signal can be canceled directly on the optical path. However, the biggest disadvantage of active noise reduction technology is its high energy consumption. Autonomous underwater vehicles usually need to operate underwater for a long time. The long-range operation requirements make energy a key limitation, and the active noise reduction system needs to continuously consume energy, making it difficult to balance energy saving and noise reduction effects in long-term missions.

[0005] On the other hand, passive noise reduction technology often relies on vibration isolation materials to achieve vibration attenuation, such as the use of vibration-damping rubber plates and protective covers (such as the CN211602151U invention patent). This method can reduce the interference of vibration on the hydrophone to a certain extent, while providing additional protection. However, the shortcoming of this type of technology is the lack of comprehensive analysis and optimization of vibrations in different directions. Underwater vehicles are affected by multi-directional vibrations in actual operations. Existing passive noise reduction designs often do not conduct in-depth research on vibrations in specific directions, resulting in uneven vibration suppression effects. In addition, when applying passive noise reduction technology in autonomous underwater vehicles, factors such as hydrodynamic shape, installation space and layout need to be comprehensively considered. At present, there is a lack of design solutions that conform the hydrophone to the shape of the underwater vehicle, which to a certain extent limits the overall effect and scope of application of this technology.

[0006] Therefore, the existing hydrophone vibration and noise reduction technology, whether active or passive, still has much room for improvement in energy saving, multi-directional vibration control and structural optimization design, and further technological innovation and improvement are urgently needed. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone, which aims to solve the shortcomings and limitations of the existing hydrophone vibration reduction and noise reduction technology in terms of energy saving, multi-directional vibration control and structural optimization design.

[0008] The present invention is achieved as follows: a quasi-zero stiffness metamaterial vibration reduction mounting structure for a hydrophone of an underwater vehicle, characterized in that it includes an oil seal end cover mounted on the front end of a front fairing of the underwater vehicle and a sound-transmitting cover mounted on the oil seal end cover, the sound-transmitting cover and the front fairing forming a flow-guiding structure, in a chamber formed on the inner side of the sound-transmitting cover, a mounting frame is fixed to the front end of the oil seal end cover, two quasi-zero stiffness vibration reduction components are arranged in front and behind the mounting frame, the outer side of the quasi-zero stiffness vibration reduction component is connected to the mounting frame, a concave portion for clamping the end of the hydrophone is formed in the middle of the quasi-zero stiffness vibration reduction component, a mounting space for arranging the hydrophone is formed between the two quasi-zero stiffness vibration reduction components, and two ends of the hydrophone are respectively clamped and clamped in the concave portions of the two quasi-zero stiffness vibration reduction components.

[0009] In the above technical solution, preferably, the quasi-zero stiffness vibration damping component is a ring-shaped component, and the concave portion is an arched concave surface formed in the middle of the quasi-zero stiffness vibration damping component and adapted to the contour of the hydrophone end.

[0010] In the above technical solution, preferably, the mounting frame includes a front annular frame, a rear annular frame and a connecting frame connected to the front annular frame and the rear annular frame, the front annular frame is fixed to the outer ring of the quasi-zero stiffness vibration damping component located in the front, and the rear annular frame is fixed to the outer ring of the quasi-zero stiffness vibration damping component located in the rear.

[0011] In the above technical solution, preferably, the quasi-zero stiffness vibration damping component is composed of a vibration damping unit cell structure, the vibration damping unit cell structure is circumferentially arranged to form an annular vibration damping structure, radial N layers of the annular vibration damping structure form the quasi-zero stiffness vibration damping component, and the outer ring of the quasi-zero stiffness vibration damping component is an outer ring structure connected to the mounting frame.

[0012] In the above technical solution, preferably, the connecting frame is an axially extending connecting frame, the two ends of the connecting frame are respectively connected to the front annular frame and the rear annular frame by fasteners, and the front annular frame and the rear annular frame are circumferentially connected to N connecting frames.

[0013] In the above technical solution, preferably, the front end of the oil seal end cover is connected to a ring-shaped frame, and the ring-shaped frame includes an outer ring frame connected to the oil seal end cover, an inner frame connected to the rear annular frame, and a radial frame connected between the outer ring frame and the inner frame.

[0014] In the above technical solution, preferably, the front end surface of the oil seal end cover is provided with connecting bosses at circumferential intervals, the outer ring frame is provided with outer ring bosses at circumferential intervals, and the outer ring bosses are connected to the connecting bosses in a one-to-one correspondence.

[0015] In the above technical solution, preferably, the annular vibration damping structure is composed of 8 vibration damping unit cell structures, including two layers of the annular vibration damping structure, and the vibration damping unit cell structures in the two layers of the annular vibration damping structure correspond one to one in radial direction.

[0016] In the above technical solution, preferably, the vibration-damping unit cell structure includes a positive stiffness zone with structural central symmetry and a negative stiffness zone with external structural bending.

[0017] In the above technical solution, preferably, the positive stiffness zone is an inner ring sleeve structure formed by four convex curved surfaces, and the negative stiffness zone is an outer ring sleeve structure formed by a convex surface located in the annular direction and a concave curved surface located in the radial direction, and the inner wall of the outer ring sleeve structure is connected to the outer wall of the inner ring sleeve structure.

[0018] The present invention provides a quasi-zero stiffness metamaterial vibration reduction device for an underwater vehicle hydrophone, which has significant advantages and effects compared to the prior art and comprehensively improves the performance and acoustic detection capability of the underwater vehicle.

[0019] First, the quasi-zero stiffness vibration damping component is designed conformally with the external structure of the hydrophone. The original overall structure of the fairing is used as the main design subject, and the size of the quasi-zero stiffness metamaterial vibration damper designed in this patent is used as the design constraint. At the same time, the installation space for the sensors required in the front fairing of the underwater vehicle is considered, and the front fairing is divided at an appropriate position, and the front is connected to the external sound-transmitting cover. The overall shape follows the Myring-type low-resistance shape of the underwater vehicle after optimization. Compared with the externally suspended hydrophone mounting method, it not only reduces the fluid resistance of the underwater vehicle when running in the water, improves the energy efficiency and speed of the vehicle, but also effectively avoids the problems of biological fouling, corrosion, and other serious damage to the working performance of the hydrophone and the vibration damping structure under long-term marine missions. This design is particularly critical for autonomous underwater vehicles with high mission requirements and large navigation ranges.

[0020] Secondly, the vibration attenuation capability of the quasi-zero stiffness metamaterial significantly enhances the vibration reduction effect of the hydrophone. Through the carefully designed quasi-zero stiffness structure, the device can effectively attenuate vibration when the vibration of the rear end of the vehicle is transmitted to the front end through the shell, especially the suppression effect of axial and radial vibrations. This structure combines positive and negative stiffness to ensure that significant vibration suppression effects can be achieved in different directions, effectively reducing the interference of the vehicle's own vibration on the hydrophone, thereby reducing noise interference in the mid- and low-frequency bands, making the acquisition of hydroacoustic signals more accurate.

[0021] In addition, the quasi-zero stiffness metamaterial structure of the present invention achieves vibration reduction while maintaining a light weight and excellent structural stability through the clever use of materials. The characteristics of this material enable the device to not only reduce vibration, but also take into account the overall structural strength of the vehicle and maintain its flexibility and durability underwater.

[0022] Another important advantage is that the device does not require additional energy consumption, greatly improving the energy efficiency of autonomous underwater vehicles. Unlike active noise reduction technology, which requires additional electricity to offset vibration noise, the passive vibration reduction design of the present invention uses the physical properties of quasi-zero stiffness metamaterials to achieve vibration attenuation, relying entirely on structural design for noise reduction. This makes the device more suitable for autonomous underwater vehicles that operate continuously for a long time, especially when energy is limited, the design has obvious advantages.

[0023] Finally, the present invention provides an innovative solution for the hydrophone installation structure of underwater vehicles, which not only improves the accuracy of underwater acoustic detection through vibration reduction design, but also provides a more stable operating platform for underwater acoustic signal recognition. The overall design takes into account the multi-dimensional vibration characteristics of the hydrophone in a complex underwater environment, significantly improving the working ability and detection accuracy of autonomous underwater vehicles in various complex marine conditions.

[0024] In general, this quasi-zero stiffness metamaterial vibration reduction device provides an efficient, stable, and low-noise hydrophone installation solution for autonomous underwater vehicles through conformal design, vibration attenuation, structural optimization, and energy-saving effects, significantly improving its performance in underwater detection and signal acquisition. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 It is the installation structure of the quasi-zero stiffness vibration reduction component in the present invention; Figure 3 Schematic diagram of the shape of the quasi-zero stiffness metamaterial vibration reduction mounting node in the present invention; Figure 4 It is a structural schematic diagram of the ring frame in the present invention; Figure 5 It is a schematic diagram of the structure of the oil seal end cover in the present invention; Figure 6 This is a vibration reduction performance diagram of the metamaterial vibration reducer of the quasi-zero stiffness metamaterial vibration reduction installation structure of the present invention; Figure 7 This is a comparison diagram of the vibration reduction performance simulation of the metamaterial vibration reduction device of the quasi-zero stiffness metamaterial vibration reduction installation structure of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] In order to solve the shortcomings and limitations of the existing hydrophone vibration reduction and noise reduction technology in terms of energy saving, multi-directional vibration control and structural optimization design, the present invention provides a quasi-zero stiffness metamaterial vibration reduction installation structure for underwater vehicle hydrophones. This quasi-zero stiffness metamaterial vibration reduction device provides an efficient, stable and low-noise hydrophone installation solution for autonomous underwater vehicles through conformal design, vibration attenuation, structural optimization and energy saving effects, which significantly improves its performance in underwater detection and signal acquisition. In order to further illustrate the structure of the present invention, the detailed description combined with the attached drawings is as follows: See also Figure 1-Figure 4 A quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone comprises an oil seal end cover 2 mounted on the front end of a front fairing 1 of the underwater vehicle and a sound-permeable cover mounted on the oil seal end cover. The sound-permeable cover and the front fairing form a flow-guiding structure. A chamber for installing a hydrophone is formed on the inner side of the sound-permeable cover. The sound-permeable cover and the front fairing adopt a conformal design and form a flow-guiding surface on the outside. The sound-permeable cover is made of polyurethane material to improve the fidelity of ocean sound signals.

[0028] The front end of the oil seal end cover is fixed with a mounting frame 3, and two quasi-zero stiffness vibration-damping components 4 are arranged in front and behind the mounting frame. The outer side of the quasi-zero stiffness vibration-damping component is connected to the mounting frame, and the middle part of the quasi-zero stiffness vibration-damping component forms a concave part for clamping the end of the hydrophone. An installation space for arranging the hydrophone 5 is formed between the two quasi-zero stiffness vibration-damping components, and the two ends of the hydrophone are clamped and clamped in the concave parts of the two quasi-zero stiffness vibration-damping components.

[0029] In this embodiment, specifically, the mounting frame includes a front annular frame 3-1, a rear annular frame 3-2, and a connecting frame 3-3 connected to the front annular frame and the rear annular frame, the front annular frame is fixed to the outer ring of the quasi-zero stiffness vibration reduction component located in the front, and the rear annular frame is fixed to the outer ring of the quasi-zero stiffness vibration reduction component located in the rear. The connecting frame is an axially extending connecting frame, and the two ends of the connecting frame are respectively connected to the front annular frame and the rear annular frame by fasteners, and the front annular frame and the rear annular frame are circumferentially connected to N connecting frames.

[0030] The front end of the oil seal end cover is connected to a ring frame 6, which includes an outer ring frame 6-1 connected to the oil seal end cover, an inner frame 6-2 connected to the rear ring frame, and a radial frame 6-3 connected between the outer ring frame and the inner frame. The front end surface of the oil seal end cover is provided with connecting bosses 2-1 at intervals in the circumferential direction, and the outer ring frame is provided with outer ring bosses 6-4 at intervals in the circumferential direction, and the outer ring bosses are connected to the connecting bosses one by one. The outer ring bosses are connected to the connecting bosses by bolts, and the radial frame structure integrated with the inner frame and the rear of the rear ring frame is connected by bolts. With lightweight as the optimization goal, the topological structure of the connecting frame is optimized so that it can reduce the influence of its own weight on the whole machine while supporting the quasi-zero stiffness metamaterial vibration reduction mechanism.

[0031] The quasi-zero stiffness vibration-damping component is a ring-shaped component, and the concave portion is an arched concave surface formed in the middle of the quasi-zero stiffness vibration-damping component and adapted to the contour of the end of the hydrophone.

[0032] The quasi-zero stiffness vibration damping component is composed of a vibration damping unit cell structure 4-1, and the vibration damping unit cell structure is arranged circumferentially to form an annular vibration damping structure, and the radial N-layer annular vibration damping structure forms a quasi-zero stiffness vibration damping component, and the outer ring of the quasi-zero stiffness vibration damping component is an outer ring structure connected to the mounting frame, and the outer ring structures of the two quasi-zero stiffness vibration damping components are connected to the front annular frame and the rear annular frame by bolts. In this embodiment, specifically, the annular vibration damping structure is composed of 8 vibration damping unit cell structures, including two layers of annular vibration damping structures, and the vibration damping unit cell structures in the two layers of annular vibration damping structures correspond radially one to one. The quasi-zero stiffness vibration damping component is a component made of polyurethane material, and the vibration damping unit cell structure includes a positive stiffness zone with a central symmetry of the structure and a negative stiffness zone with a curved external structure. The central symmetric positive stiffness zone is responsible for maintaining the overall rigidity and stability. The negative stiffness zone with an external curved shape exhibits a negative stiffness effect after being subjected to force, which helps to absorb shock or vibration. This design can exhibit quasi-zero stiffness characteristics under low-frequency vibration, adjust the overall stiffness of the structure through geometric deformation, and achieve vibration reduction and vibration isolation effects. For the design of the quasi-zero stiffness vibration damping layer, 8 materials are selected, and a double-layer circumferential 8 vibration damping unit cell structure is adopted. The vibration damping unit cell structure adopts a quasi-zero stiffness design combining positive and negative stiffness. Through 4 groups of negative stiffness structures in the transverse and longitudinal directions and the internal positive stiffness structure design, effective suppression of low-frequency vibration noise is achieved.

[0033] The geometry of this design can show excellent vibration reduction performance within a specific frequency range through the combination of positive and negative stiffness. The positive stiffness area is an inner ring structure formed by four convex curved surfaces, and the negative stiffness area is an outer ring structure formed by a convex surface in the annular direction and a concave curved surface in the radial direction. The inner wall of the outer ring structure is connected to the outer wall of the inner ring structure.

[0034] Further, in this embodiment, please refer to Figure 5 The specific installation structure of the oil seal end cover is as follows: the oil seal end cover is connected and fixed to the front fairing by circumferential bolts, the front part of the oil seal end cover is connected and fixed to the sound-permeable cover 7 by axial bolts, and the sealing effect is achieved by cooperating with the sealing O-ring at the same time. The front and rear directions described here and above correspond to the front and rear directions of the underwater glider. The oil seal end cover is connected to the outer ring frame of the ring frame through four circumferential connecting bosses and fixed by bolts.

[0035] When installing the oil seal end cover, install the sealing O-ring in the sealing groove 2-2 set on it, connect the boss to the unequally spaced coil spring bolts, and bolt the sound-permeable cover to clamp it through four circumferential positioning holes. Connect the sealing structure, open the air extraction hole, connect the outside to the air pump, observe the cabin pressure of the oil seal structure through the test computer, connect the oil pipeline, and fill the oil seal structure with oil. After the set negative pressure value is pumped, tighten the air extraction plug. When the oil is full, unscrew the exhaust plug and remove the oil pipeline. In addition, the data transmission connector is connected to the rear-end data transmission cable on the outside and to the hydrophone data transmission cable on the inside. When not in operation, the connector is connected to the watertight penetration part.

[0036] like Figure 6 As shown in the figure, the vibration transmissibility of the optimized quasi-zero stiffness unit cell structure was simulated and verified. The main process is: input excitation, then pick up the acceleration response of the input and output ends in the software, calculate the vibration transmissibility of each frequency band by formula (1), and verify the effectiveness of the low-frequency vibration reduction performance of the vibration reduction structure. The results show that the vibration transmissibility is negative in the whole frequency range, indicating that the quasi-zero stiffness vibration reduction mechanism has a good vibration reduction effect in the range of 1-2000 Hz. In addition, three troughs are generated in the range of 1-1000 Hz, indicating that the quasi-zero stiffness vibration reduction mechanism has a significant vibration reduction effect in the medium and low frequency range.

[0037]

[0038] In the formula T is the vibration transmissibility, U O is the acceleration response at the output, U I is the acceleration response at the input.

[0039] like Figure 7 As shown in the figure, the simulation comparison results of the quasi-zero stiffness vibration reduction mechanism by comparing different numbers of vibration reduction layers are shown. The simulation conditions are set to 1 layer, 2 layers and 3 layers respectively. On the basis of ensuring that the overall shape remains unchanged, the overall size of the unit cell structure increases accordingly as the number of layers decreases, and the total width H remains unchanged. The analysis results are shown in the figure. It can be found that when the number of vibration reduction layers is 2, a broadband vibration isolation belt can be generated in the 1-500 Hz frequency band, ensuring a good low-frequency vibration reduction effect. Therefore, a design scheme of 2 vibration reduction layers combined with 8 circumferential vibration reduction units is selected.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone, characterized in that: The invention comprises an oil seal end cover installed at the front end of a front fairing of an underwater vehicle and a sound-transmitting cover installed on the oil seal end cover, wherein the sound-transmitting cover and the front fairing form a flow-guiding structure, wherein a mounting frame is fixed to the front end of the oil seal end cover in a chamber formed inside the sound-transmitting cover, wherein two quasi-zero stiffness vibration-damping components are arranged in front and behind the mounting frame, wherein the outer sides of the quasi-zero stiffness vibration-damping components are connected to the mounting frame, wherein a concave portion for clamping the ends of a hydrophone is formed in the middle portion of the quasi-zero stiffness vibration-damping components, wherein an installation space for arranging a hydrophone is formed between the two quasi-zero stiffness vibration-damping components, and wherein two ends of the hydrophone are clamped and clamped in the concave portions of the two quasi-zero stiffness vibration-damping components respectively.

2. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 1, characterized in that: The quasi-zero stiffness vibration-damping component is a ring-shaped component, and the concave portion is an arched concave surface formed in the middle of the quasi-zero stiffness vibration-damping component and adapted to the contour of the end of the hydrophone.

3. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 2, characterized in that: The mounting frame includes a front annular frame, a rear annular frame and a connecting frame connected to the front annular frame and the rear annular frame. The front annular frame is fixed to the outer ring of the quasi-zero stiffness vibration damping component located in the front, and the rear annular frame is fixed to the outer ring of the quasi-zero stiffness vibration damping component located in the rear.

4. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 3, characterized in that: The quasi-zero stiffness vibration damping component is composed of a vibration damping unit cell structure, which is circumferentially arranged to form an annular vibration damping structure. N radial layers of the annular vibration damping structure form the quasi-zero stiffness vibration damping component, and the outer ring of the quasi-zero stiffness vibration damping component is an outer ring structure connected to the mounting frame.

5. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 4, characterized in that: The connecting frame is an axially extending connecting frame, and the two ends of the connecting frame are respectively connected to the front annular frame and the rear annular frame through fasteners, and the front annular frame and the rear annular frame are circumferentially connected to N connecting frames.

6. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 5, characterized in that: The front end of the oil seal end cover is connected to a ring frame, and the ring frame comprises an outer ring frame connected to the oil seal end cover, an inner frame connected to the rear annular frame, and a radial frame connected between the outer ring frame and the inner frame.

7. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 6, characterized in that: The front end surface of the oil seal end cover is provided with connecting bosses at intervals in the circumferential direction, and the outer ring frame is provided with outer ring bosses at intervals in the circumferential direction, and the outer ring bosses are connected with the connecting bosses in a one-to-one correspondence.

8. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 7, characterized in that: The annular vibration reduction structure is composed of 8 vibration reduction unit cell structures, including two layers of the annular vibration reduction structure, and the vibration reduction unit cell structures in the two layers of the annular vibration reduction structure correspond to each other radially.

9. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 8, characterized in that: The vibration-damping unit cell structure comprises a positive stiffness region with structural central symmetry and a negative stiffness region with external structural bending.

10. The quasi-zero stiffness metamaterial vibration reduction mounting structure for an underwater vehicle hydrophone according to claim 10, characterized in that: The positive stiffness zone is an inner ring structure formed by four convex curved surfaces, and the negative stiffness zone is an outer ring structure formed by a convex surface located in the annular direction and a concave curved surface located in the radial direction, and the inner wall of the outer ring structure is connected to the outer wall of the inner ring structure.

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