A high-efficiency damping device and method based on a surface wave damping mechanism phononic crystal sandwich structure

Abstract

The application provides a high-efficiency damping device and method based on a surface wave damping mechanism phononic crystal sandwich structure, and belongs to the field of ship damping and noise reduction. The device solves the problems of poor low-frequency damping effect, narrow damping frequency band and high cost-effectiveness ratio of existing damping devices. The device comprises a high-damping bearing panel, a damping liquid capsule, a phononic crystal sandwich panel and a bottom plate structure. The bottom plate structure is connected with a ship plate, the phononic crystal sandwich panel is fixed on the bottom plate structure, the damping liquid capsule is arranged on the phononic crystal sandwich panel, and the high-damping bearing panel is arranged on the damping liquid capsule. The damping liquid capsule comprises a liquid capsule body and a liquid capsule limiting mechanism. The liquid capsule limiting mechanism is fixed on the phononic crystal sandwich panel, the liquid capsule body is arranged in a space surrounded by the liquid capsule limiting mechanism, and the liquid capsule body is filled with fluid medium. The phononic crystal sandwich panel comprises an upper panel, a lower panel and a phononic crystal array. The phononic crystal array comprises a plurality of local resonance phononic crystals. The application is suitable for effective damping of ship mechanical equipment during operation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ship vibration and noise reduction, and particularly relates to a high-efficiency vibration reduction device and method based on a surface wave vibration reduction mechanism phononic crystal sandwich structure. BACKGROUND

[0002] Mechanical noise is generated by the operation of mechanical equipment, and as one of the three major noise sources of a ship, it directly affects the comfort, economy and service life of the ship. A ship is a large structure that relies on the cooperation of multiple systems, and the daily operation of the ship depends on many mechanical equipment inside. Although the types of mechanical equipment are different, the fixing methods are basically the same: various types of mechanical equipment are connected to the ship body plate through one or more structures, which are base structures. As the main structure connecting the ship body and the mechanical equipment, the base structure is the main channel for the vibration generated by the operation of the mechanical equipment to be transmitted to the ship body, and is also one of the main ways to reduce the vibration and noise of the mechanical equipment. In recent years, experts and scholars have conducted in-depth research on the vibration and noise reduction of ship mechanical equipment, mainly through the dynamic optimization of base structure parameters, the development of high-performance vibration isolators, and the setting of vibration absorption devices to reduce the level of ship mechanical noise. However, due to the limitations of existing technologies, it is difficult to combine the advantages of wide frequency band, low cost and high performance. Therefore, based on the energy stratification theory and water wave theory, it has certain engineering significance to design a high-efficiency vibration reduction device based on a surface wave vibration reduction mechanism phononic crystal sandwich structure.

[0003] Through the existing literature and patent retrieval, it is found that the similar public information of the present application mainly includes: 1. Vibration and noise reduction research of local resonance phononic crystal plate (Ship Mechanics, 2021, 25); 2. Research on vibration reduction characteristics of ship machinery based on phononic crystals (Journal of Chongqing Jiaotong University, 2020, 39); 3. Three-dimensional phononic crystal vibration reduction device based on air bag (Chinese invention: CN201810524316.9); 4. Local resonance type phononic crystal vibration reduction device and equipment (Chinese invention: CN202210421694.0).

[0004] Document 1 proposes a phononic crystal plate structure with an additional cylindrical vibrator for the vibration and noise control of ship equipment and structure, uses the finite element method, vibration transmission rate and sound insulation loss to analyze the influence of scatterer geometric parameters and arrangement form on vibration and sound insulation effect, which is quite different from the present patent; Document 2 designs a phononic crystal plate with a multi-element composite cylindrical periodic arrangement, analyzes and calculates the band gap characteristics, vibration transmission loss and sound insulation effect through COMSOL finite element software, but the designed phononic crystal in this paper has certain effect on low-frequency excitation attenuation, and the shock absorption effect still has a large room for improvement, and the strength of the structure still needs to be considered; Invention patent 3 discloses a three-dimensional phononic crystal damping device based on air bag, applies the concept of phononic crystal to the damping structure, forms a two-dimensional phononic crystal by attaching an air bag to a metal material scatterer, and then arranges it in the third dimension to form a three-dimensional phononic crystal, which controls the connection stiffness of the scatterer by controlling the inflation and deflation of the air bag, adjusts the damping frequency band interval, which is quite different from the present invention, and the phononic crystal is composed of scatterers and matrix, and the connection between different materials is a big problem, and it is difficult to ensure the structural strength when a large mass equipment is installed; Invention patent 4 discloses a local resonance type phononic crystal damping device and equipment, the vibrator of the phononic crystal is provided with a centroid adjusting piece, the centroid adjusting piece is connected with a lifting mechanism installed on the frame, and the centroid adjusting piece adjusts the centroid position of the vibrator to realize the adjustment of the band gap of the phononic crystal, which is quite different from the present invention.

[0005] In summary, the differences between the currently published literatures, patents and the present invention are large, and there are certain limitations in structure form, structural strength, damping effect and economic cost. Therefore, the present invention designs a high-efficiency damping device based on the surface wave damping mechanism of the phononic crystal sandwich structure, which has the characteristics of simple structure, good damping performance, small processing difficulty, low economic cost and important significance for mechanical equipment damping and noise reduction. SUMMARY

[0006] Therefore, the present invention creates a high-efficiency damping device based on the surface wave damping mechanism of the phononic crystal sandwich structure to solve the problems of poor low-frequency damping effect, narrow damping frequency band coverage and high cost-effectiveness of the existing damping device.

[0007] To achieve the above-mentioned purpose, the technical scheme of the present invention is as follows:

[0008] A high-efficiency damping device based on the surface wave damping mechanism of the phononic crystal sandwich structure, comprising a high-damping bearing panel, a damping liquid bag, a phononic crystal sandwich plate and a bottom plate structure, the bottom plate structure is connected with the ship body plate, the phononic crystal sandwich plate is fixedly arranged on the bottom plate structure, the damping liquid bag is arranged on the phononic crystal sandwich plate, and the high-damping bearing panel is installed on the damping liquid bag;

[0009] The damping liquid bag comprises a liquid bag body and a liquid bag limiting mechanism, the liquid bag limiting mechanism is fixed on the phononic crystal sandwich plate, the liquid bag body is arranged in the space surrounded by the liquid bag limiting mechanism, and the liquid bag body is filled with fluid medium.

[0010] The phononic crystal sandwich plate comprises an upper panel, a lower panel and a phononic crystal array, the phononic crystal array is arranged between the upper panel and the lower panel, and the phononic crystal array comprises a plurality of local resonance phononic crystals.

[0011] Further, the damping liquid bag further comprises a plurality of pore partitions, a plurality of pore partitions with different heights are arranged in the liquid bag body, and a plurality of through holes with different sizes are arranged on the pore partitions.

[0012] Further, the local resonance phononic crystal comprises a phononic crystal rigid frame, a local resonance unit and a spring, the phononic crystal rigid frame is fixedly connected with the upper panel and the lower panel, the bottom end of the spring is installed in the phononic crystal rigid frame, and the local resonance unit is installed at the top end of the spring.

[0013] Further, the bottom plate structure comprises a bottom panel and a plurality of base foot pads, and the plurality of base foot pads are fixedly connected at the periphery of the lower surface of the bottom panel.

[0014] Further, the high-damping bearing panel comprises a rubber sleeve and a steel plate, the steel plate is arranged in the rubber sleeve, and the rubber sleeve and the liquid bag body are integrally formed.

[0015] Further, the liquid bag limiting mechanism comprises two oppositely arranged limiting plates, the bottom of each of the two limiting plates is fixed on the upper panel, and the liquid bag body is arranged in the space between the two limiting plates.

[0016] Further, the bottom of the liquid bag body is tightly attached to the upper panel of the phononic crystal sandwich plate, the lower panel of the phononic crystal sandwich plate is fixedly connected with the bottom panel through bolts, and the bottom panel is connected with the ship body plate through bolts.

[0017] Further, the bottom end and the two sides of the pore partition are connected with the liquid bag body, a gap is arranged between the top end of the pore partition and the liquid bag body, and the pore partition is provided with large through holes and small through holes arranged in a staggered manner.

[0018] Further, the mechanical equipment is fixed on the steel plate of the high-damping bearing panel through machine foot bolts.

[0019] Another object of the present application is to provide a damping method of a high-efficiency damping device based on a surface wave damping mechanism and a phononic crystal sandwich structure, which specifically comprises:

[0020] When the mechanical equipment is running, mechanical vibration will be transmitted downward from the machine foot to the high-damping bearing panel, the vibration is attenuated in the damping bearing panel, and then transmitted to the damping liquid bag, at this time the vibration energy is mainly gathered on the fluid surface, and with the increase of water depth, the energy is exponentially attenuated, and the higher the vibration frequency, the less the energy is transmitted downward, so as to realize the attenuation of the vibration again, and the liquid and the internal pore partition plate interact to realize energy dissipation, when the vibration is transmitted downward to the phononic crystal sandwich panel, the local resonance mode of the phononic crystal under the excitation of the specific frequency will induce the resonance band gap at the corresponding intrinsic frequency, so as to isolate the transmission of the vibration of the specific frequency, realize the damping again, and the mechanical vibration is transmitted to the ship body through the bottom plate structure after multiple attenuations.

[0021] Compared with the prior art, the beneficial effects of the high-efficiency damping device based on the surface wave damping mechanism and the phononic crystal sandwich structure are:

[0022] (1) The high-efficiency damping device based on the surface wave damping mechanism and the phononic crystal sandwich structure reduces the transmission of the vibration of the mechanical equipment to the ship body structure through the combination of the high-damping bearing panel, the damping liquid bag and the phononic crystal sandwich panel.

[0023] (2) The high-efficiency damping device based on the surface wave damping mechanism and the phononic crystal sandwich structure is composed of the phononic crystal unit and the upper and lower panels, and can adjust the structure property and the excitation frequency to realize matching in combination with the excitation characteristics of the equipment, so as to have strong equipment applicability.

[0024] (3) The high-efficiency damping device based on the surface wave damping mechanism and the phononic crystal sandwich structure is simple in structure and high in reliability, in addition to the integrated structure, the structures are connected by bolts, and are convenient to disassemble; the four component structures are low in processing difficulty and controllable in manufacturing cost.

[0025] (4) The high-efficiency damping device based on the surface wave damping mechanism and the phononic crystal sandwich structure dissipates the vibration energy generated by the running of the mechanical equipment through the high-damping bearing panel, the damping liquid bag and the phononic crystal sandwich panel based on the surface wave damping mechanism, the water wave theory and the phononic crystal damping principle, and realizes the high-efficiency damping effect of the mechanical equipment by multiple measures.

[0026] (5) The high-efficiency damping device based on the surface wave damping mechanism and the phononic crystal sandwich structure can replace the liquid in the damping liquid bag according to the damping requirement, so as to improve the damping effect.

[0027] (6) The high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application has a liquid capsule limiting mechanism connected with the upper panel of the phononic crystal sandwich plate, which can limit the horizontal displacement of the damping liquid capsule and limit the vertical displacement to avoid the structure damage caused by the large load of the liquid capsule.

[0028] (7) The high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application has a phononic crystal which can be designed according to the characteristics of the device excitation source, and the matching with the excitation frequency is realized by adjusting the internal spring stiffness and the local resonance unit properties, so that the elastic wave band gap in a specific frequency band is excited.

[0029] (8) The high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application has a layered stacking form, and the damping structures between the layers are integrally formed or connected by bolts, so that the overall structural strength is ensured.

[0030] (9) The traditional damping device has high cost-effectiveness, that is, high cost and poor effect. The damping device disclosed by the application realizes multi-layer attenuation of vibration energy in a layered manner to achieve high-efficiency damping effect, and the device has simple structure, controllable processing cost and low cost-effectiveness. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated herein in their entirety. The embodiments of the application illustrated in the drawings and their descriptions are used to explain the application and are not intended to limit the application. In the drawings:

[0032] Figure 1 The structure schematic view of the high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application;

[0033] Figure 2 The structure schematic view of the high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application;

[0034] Figure 3 The structure schematic view of the high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application;

[0035] Figure 4 The structure schematic view of the high-efficiency damping device based on the surface wave damping mechanism phononic crystal sandwich structure provided by the application;

[0036] Figure 5A perspective view of a bottom plate structure in a high-efficiency damping device based on a surface wave damping mechanism phononic crystal sandwich structure according to an embodiment of the present invention;

[0037] Figure 6 A structural schematic diagram of a mechanical equipment damping structure using a high-efficiency damping device based on a surface wave damping mechanism phononic crystal sandwich structure according to an embodiment of the present invention.

[0038] Legend of reference signs:

[0039] 1, mechanical equipment; 2, high-damping bearing panel; 3, damping liquid bag; 4, phononic crystal sandwich plate; 5, bottom plate structure; 6, liquid bag body; 7, pore partition; 8, liquid bag limiting mechanism; 9, upper panel; 10, phononic crystal array; 11, lower panel; 12, phononic crystal rigid frame; 13, local resonance unit; 14, spring; 15, bottom panel; 16, fixing hole; 17, base foot pad. DETAILED DESCRIPTION

[0040] The technical solutions of the present invention will be described clearly and completely below in combination with the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0043] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] like Figures 1-6 As shown, a high-efficiency vibration reduction device based on a phonon crystal sandwich structure with surface wave vibration reduction mechanism includes a high-damping load-bearing panel 2, a damping liquid bladder 3, a phonon crystal sandwich plate 4, and a base plate structure 5. The base plate structure 5 is connected to the hull plate, the phonon crystal sandwich plate 4 is fixedly arranged on the base plate structure 5, the damping liquid bladder 3 is disposed on the phonon crystal sandwich plate 4, the high-damping load-bearing panel 2 is installed on the damping liquid bladder 3, and the target object is installed on the high-damping load-bearing panel 2.

[0045] The damping liquid bladder 3 includes a liquid bladder body 6 and a liquid bladder limiting mechanism 8. The liquid bladder limiting mechanism 8 is fixed on the phononic crystal sandwich plate 4. The liquid bladder body 6 is disposed within the space enclosed by the liquid bladder limiting mechanism 8 and is filled with a fluid medium. The phononic crystal sandwich plate 4 includes an upper panel 9, a lower panel 11, and a phononic crystal array 10. The phononic crystal array 10 is arranged between the upper panel 9 and the lower panel 11 and includes a plurality of locally resonant phononic crystals.

[0046] The damping liquid bladder 3 is mainly used for mid-to-high frequency vibration reduction, and the phonon crystal sandwich plate 4 is mainly used for low-frequency vibration reduction.

[0047] The damping liquid bladder 3 also includes several porous baffles 7. Multiple porous baffles of different heights are provided inside the liquid bladder body 6, and several through holes of different sizes are opened on the porous baffles 7. Specifically, the bottom end and both sides of the porous baffles 8 are connected to the liquid bladder body 6, and there is a gap between the top end of the porous baffles 7 and the liquid bladder body 6. Large through holes and small through holes are arranged alternately on the porous baffles 7.

[0048] When the fluid medium flows in the liquid bladder, the fluid will interact with the pore partitions 7. During this process, the work done will be dissipated in the form of energy, further promoting the attenuation of vibration energy.

[0049] The damping liquid bladder 3 possesses excellent mid-to-high frequency vibration damping performance. The vibrations generated by the operation of the target object are transmitted through the structure in the form of waves. According to the wave mode conversion principle, waves in the structure are converted into surface waves at the interface between the structure and the fluid medium, and only longitudinal waves continue to propagate downwards, achieving energy attenuation to a certain extent. Based on the water wave theory at finite water depth, wave energy mainly accumulates on the fluid surface and decreases exponentially with increasing water depth. Furthermore, the higher the vibration frequency, the less energy is transmitted downwards, thus achieving vibration attenuation, especially with a more pronounced high-frequency vibration damping effect.

[0050] The local resonance phononic crystal includes a phononic crystal rigid frame 12, a local resonance unit 13 and a spring 14, the phononic crystal rigid frame 12 is fixedly connected with the upper panel 9 and the lower panel 11, the bottom end of the spring 14 is installed in the phononic crystal rigid frame 12, and the local resonance unit 13 is installed at the top end of the spring 14. The local resonance unit 13 of the local resonance phononic crystal needs to be designed according to the characteristics of the device excitation source. When the vibration wave is transmitted to the phononic crystal sandwich plate after being attenuated by the damping liquid bag, the local resonance mode of the phononic crystal under the excitation of a specific frequency will induce a resonance band gap at the corresponding natural frequency, thereby isolating the transmission of vibration at a specific frequency, and the phononic crystal sandwich plate 4 mainly has a significant low-frequency damping effect.

[0051] The bottom plate structure includes a bottom panel 15 and a plurality of base foot pads 17 fixedly connected at the periphery of the lower surface of the bottom panel 15. The base foot pad 17 is an L-shaped structure, and the height adjusting device is convenient to install.

[0052] The high-damping bearing panel 2 includes a rubber sleeve and a steel plate, the steel plate is arranged in the rubber sleeve, and the rubber sleeve and the liquid bag body 6 are integrally formed. When the target object is running, vibration is inevitably generated by reciprocating work, and the vibration is transmitted to the high-damping bearing panel 2 through the equipment feet. The high-damping bearing panel 2 is different from the conventional steel panel and is composed of a damping material and a steel plate, has a high damping characteristic, can realize energy dissipation to a certain extent through structural deformation while realizing the bearing of the mechanical equipment, and reduces the downward transmission of equipment vibration.

[0053] The liquid bag limiting mechanism 8 includes two oppositely arranged limiting plates, the bottoms of the two limiting plates are fixed on the upper panel 9, and the liquid bag body 6 is arranged in the space between the two limiting plates; and there is a certain gap between the liquid bag limiting mechanism 8 and the liquid bag body 6, so as to avoid contact with the liquid bag during normal work of the liquid bag, while limiting the displacement of the liquid bag in the horizontal direction and preventing the liquid bag from being crushed and failed under high pressure.

[0054] The liquid bag body 6 is tightly attached to the upper panel 9 of the phononic crystal sandwich plate 4, the lower panel 11 of the phononic crystal sandwich plate 4 is fixedly connected with the bottom panel 15 through bolts, and the bottom panel 15 is connected with the ship body plate through bolts. The mechanical equipment 1 is fixed on the steel plate of the high-damping bearing panel 2 through the feet bolts.

[0055] A damping method of a high-efficiency damping device based on a surface wave damping mechanism phononic crystal sandwich structure, specifically comprising: when the mechanical equipment 1 is running, mechanical vibration will be transmitted downward from the machine foot to the high-damping bearing panel, and the vibration will be attenuated in the damping bearing panel, and then transmitted to the damping liquid capsule; based on wave type conversion and water wave theory, the liquid and the internal pore partition plate interact to realize energy dissipation; on this basis, due to the band gap characteristics of the phononic crystal sandwich plate at a specific frequency, the vibration transmission at the frequency can be greatly isolated; based on the wave type conversion principle and the surface wave damping mechanism, the vibration energy is mainly gathered on the surface of the fluid, and the vibration frequency is higher, the energy is less transmitted downward, the vibration can be attenuated again, and the liquid and the internal pore partition plate interact to realize energy dissipation; when the vibration is transmitted downward to the phononic crystal sandwich plate, the local resonance mode of the phononic crystal under specific frequency excitation will induce a resonance band gap at the corresponding intrinsic frequency, thereby isolating the transmission of vibration at a specific frequency and achieving secondary damping; the mechanical vibration is transmitted to the ship body by the bottom plate structure after multiple attenuations.

[0056] After the damping device of the application, the vibration attenuation in the full frequency band can be effectively realized, the mechanical vibration is transmitted to the ship body by the bottom plate structure after multiple attenuations, and the influence of the mechanical equipment operation on the ship body structure vibration is effectively reduced.

[0057] A specific example of a high-efficiency damping device based on a surface wave damping mechanism phononic crystal sandwich structure is given below:

[0058] The overall structure of the damping device is 1200mm long, 600mm wide and 195mm high, mainly composed of a high-damping bearing panel 2, a damping liquid capsule 3, a phononic crystal sandwich plate 4 and a bottom plate 5; wherein the bottom plate 5 is located at the bottom of the damping device, connected with the ship body plate to ensure the stability of the whole device; the phononic crystal sandwich plate 4 is arranged in the middle of the bottom plate 5, mainly for damping and supporting; the chain damping liquid capsule 3 is installed close to the phononic crystal sandwich plate 4, which plays a wave type conversion and vibration transmission role; finally, the mechanical equipment 1 is installed on the high-damping bearing panel 2; in addition to the integrated structure, the structures and devices are connected by bolts, which is simple in structure and convenient to disassemble and assemble.

[0059] According to the design requirements, the high-damping bearing panel 2 has a structure with a length of 1050mm, a width of 450mm, and a thickness of 5mm. The high-damping bearing panel 2 is directly integrated with the liquid tank 3, and serves as a fixing device, a connecting structure, and a vibration transmission device. The liquid tank 3 has a structure with a length of 1000mm, a width of 400mm, and a height of 100mm. The liquid tank 3 is mainly composed of a liquid tank 6, a pore partition plate 7, and a liquid tank limiting mechanism 8. The liquid tank limiting mechanism 8 is fixed on the phononic crystal sandwich panel 4 by welding, and the edges are chamfered to avoid scratching the liquid tank 6 and causing liquid leakage. The liquid tank limiting mechanism 8 serves to limit the horizontal displacement and vertical displacement of the liquid tank 6, thereby ensuring the safety of the structure. The liquid tank 6 is arranged in the liquid tank limiting mechanism 7, and the top of the liquid tank 6 is tightly attached to the high-damping bearing panel 2, thereby serving as a vibration transmission device. The pore partition plate 8 is integrated with the liquid tank 6, and mainly serves to increase the contact area with the liquid and increase the energy dissipation. Meanwhile, the liquid medium in the liquid tank 6 can be replaced according to actual requirements.

[0060] According to the design requirements, the phononic crystal sandwich panel 4 has a structure with a length of 1050mm, a width of 450mm, and a height of 56mm. The phononic crystal sandwich panel 4 is mainly composed of an upper panel 9, a phononic crystal array 10, and a lower panel 11. The phononic crystal array 10 is composed of a phononic crystal rigid frame 12, a local resonance unit 13, and a spring 14. The phononic crystal array 10 is fixed between the upper panel 9 and the lower panel 11. The specific connection method depends on the actual design material, such as full-welded connection for a steel structure or adhesive connection for a rubber structure. The phononic crystal array 10 mainly serves as a vibration reduction and connection device. The local resonance unit 13 is a conventional structure in the field of phononic crystal vibration reduction and noise reduction, and its working principle is not described here.

[0061] According to the design requirements, the bottom plate 5 has a length of 1200mm, a width of 600mm, and a thickness of 10mm. Twelve fixing holes 16 with a diameter of 16mm are arranged on the bottom panel 15 for fixing the overall structure of the vibration reduction device to the ship plate. Four "L"-shaped base foot pads 17 are arranged at the four corners of the bottom plate 5 near the ship body, thereby raising the device for easy installation.

[0062] When the marine mechanical equipment 1 is running, reciprocating work inevitably generates vibration, when the mechanical equipment 1 installed on the high-damping bearing panel 2 runs and generates vibration, the vibration will be transmitted from the equipment foot to the high-damping bearing panel 2, under the damping effect of the high-damping bearing panel 2, the energy is firstly attenuated, that is, the high-damping bearing panel 2 can safely generate deformation within a range to realize the preliminary dissipation of vibration energy; at the same time, the mechanical vibration will be transmitted in the form of wave in the structure, and wave conversion will occur at the interface between the elastic body and the fluid medium, that is, the vibration will be transmitted from the high-damping bearing panel 2 to the damping liquid bag 3, based on the wave conversion and the water wave theory, the elastic wave is converted into surface wave in the process, the vibration energy is mainly gathered on the fluid surface, and only the longitudinal wave can continue to be transmitted downward, the energy is exponentially attenuated with the increase of water depth, and the higher the frequency is, the shorter the corresponding wavelength is, and the shorter the corresponding energy downward propagation distance is, so that the vibration attenuation, especially the high-frequency vibration attenuation, can be realized; thereafter, the fluid flows in the liquid bag and interacts with the pore partition plate 7 arranged in the liquid bag to realize the energy dissipation and further damping effect; on this basis, because the vibration of a specific frequency will induce the resonance mode of the phononic crystal to resonate at the corresponding intrinsic frequency to induce the resonance band gap, the vibration in the band gap frequency range is blocked from continuing to be transmitted; therefore, the phononic crystal sandwich plate 4 designed according to the characteristics of the equipment excitation source will induce the resonance band gap when it is subjected to the vibration transmitted from the damping liquid bag 3, so as to limit the transmission of vibration in a specific frequency band; at this time, the vibration energy transmitted to the bottom plate structure 5 has been greatly attenuated, so that the influence of mechanical vibration on the acoustic performance of the ship can be effectively reduced. The mechanical vibration is greatly attenuated under the multiple actions of the damping device, the energy transmission to the ship structure is reduced, and the acoustic performance of the ship is ensured.

[0063] The above disclosed embodiments of the present application are only used to help explain the present application. The embodiments do not describe all the details, nor limit the present application to the specific embodiments described. According to the content of the present application, many modifications and changes can be made. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application.

Claims

1. A high-efficiency vibration reduction device based on a phonon crystal sandwich structure with surface wave vibration reduction mechanism, characterized in that: The system includes a high-damping load-bearing panel (2), a damping liquid bladder (3), a phononic crystal sandwich panel (4), and a bottom plate structure (5). The bottom plate structure (5) is connected to the hull plate. The phononic crystal sandwich panel (4) is fixedly arranged on the bottom plate structure (5). The damping liquid bladder (3) is arranged on the phononic crystal sandwich panel (4). The high-damping load-bearing panel (2) is installed on the damping liquid bladder (3). The damping liquid bladder (3) includes a liquid bladder body (6) and a liquid bladder limiting mechanism (8). The liquid bladder limiting mechanism (8) is fixed on the phononic crystal sandwich plate (4). The liquid bladder body (6) is set in the space enclosed by the liquid bladder limiting mechanism (8). The liquid bladder body (6) is filled with a fluid medium. The phononic crystal sandwich panel (4) includes an upper panel (9), a lower panel (11), and a phononic crystal array (10). The phononic crystal array (10) is arranged between the upper panel (9) and the lower panel (11), and the phononic crystal array (10) includes a plurality of locally resonant phononic crystals.

2. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 1, characterized in that: The damping liquid bladder (3) also includes several porous partitions (7). Multiple porous partitions (7) of different heights are provided in the liquid bladder body (6), and several through holes of different sizes are opened on the porous partitions (7).

3. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 1, characterized in that: The local resonant phononic crystal includes a rigid phononic crystal frame (12), a local resonant unit (13), and a spring (14). The rigid phononic crystal frame (12) is fixedly connected to the upper panel (9) and the lower panel (11). The bottom end of the spring (14) is installed inside the rigid phononic crystal frame (12), and the local resonant unit (13) is installed at the top end of the spring (14).

4. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 1, characterized in that: The base plate structure includes a base plate (15) and several base pads (17), which are fixedly connected to the lower surface of the base plate (15) around the perimeter.

5. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 1, characterized in that: The high-damping load-bearing panel (2) includes a rubber sleeve and a steel plate, with the steel plate arranged inside the rubber sleeve. The rubber sleeve and the liquid bladder body (6) are integrally formed and arranged.

6. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 1, characterized in that: The liquid bladder limiting mechanism (8) includes two limiting plates arranged opposite each other. The bottom of both limiting plates is fixed on the top plate (9), and the liquid bladder body (6) is arranged in the space between the two limiting plates.

7. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 4, characterized in that: The bottom of the liquid bladder body (6) is tightly attached to the upper panel (9) of the phononic crystal sandwich plate (4). The lower panel (11) of the phononic crystal sandwich plate (4) is fixedly connected to the bottom panel (15) by bolts. The bottom panel (15) is connected to the hull plate by bolts.

8. The high-efficiency vibration reduction device based on a phonon crystal sandwich structure with surface wave vibration reduction mechanism according to claim 2, characterized in that: The bottom and both sides of the pore partition (7) are connected to the liquid bladder body (6). There is a gap between the top of the pore partition (7) and the liquid bladder body (6). The pore partition (7) is provided with large through holes and small through holes arranged in an alternating manner.

9. The high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to claim 5, characterized in that: The mechanical equipment (1) is fixed on the steel plate of the high-damping load-bearing panel (2) by machine foot bolts.

10. A vibration reduction method for a high-efficiency vibration reduction device based on a phononic crystal sandwich structure with surface wave vibration reduction mechanism according to any one of claims 1-9, characterized in that: Specifically, it includes: When the mechanical equipment (1) is running, the mechanical vibration will be transmitted downward from the machine foot to the high damping bearing panel (2). The vibration is attenuated to a certain extent in the damping bearing panel and then transmitted to the damping liquid bladder (3). At this time, the vibration energy is mainly concentrated on the surface of the fluid and decreases exponentially with the increase of water depth. The higher the vibration frequency, the less energy is transmitted downward, which can realize the vibration attenuation again. At the same time, the interaction between the liquid and the internal pore baffle (7) realizes energy dissipation. When the vibration is transmitted downward to the phonon crystal sandwich plate (4), the phonon crystal will induce a resonance band gap at the corresponding intrinsic frequency under the excitation of a specific frequency, thereby isolating the transmission of the specific frequency vibration and realizing the vibration attenuation again. After multiple attenuations, the mechanical vibration is transmitted to the hull by the bottom plate structure (5).

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