Ship cabin sound insulation and vibration reduction partition plate with acoustic black holes and design method of ship cabin sound insulation and vibration reduction partition plate

Abstract

The invention relates to the technical field of composite board structures, in particular to a ship cabin sound insulation and vibration reduction partition board with acoustic black holes and a design method of the ship cabin sound insulation and vibration reduction partition board. The partition plate comprises an acoustic black hole thin plate layer, a damping material layer and a honeycomb plate layer. A plurality of groups of acoustic black hole structures are arranged on the acoustic black hole thin plate layer in an array form, and the thickness of an acoustic black hole region meets a power law; the damping material layer is used for forming an energy buffering interface, and the two faces of the damping material layer are connected with the acoustic black hole thin plate layer and the honeycomb plate layer correspondingly. The cellular board layer is used for completing acoustic radiation impedance matching suppression. Through the gradient impedance design of each functional layer, a complete sound vibration control chain of vibration capture-energy dissipation-sound wave impedance matching is constructed, the sound insulation index can be improved without increasing the system mass, and the method is particularly suitable for ship cabins and other application scenes which are sensitive to weight and need broadband noise reduction.

Description

Technical Field

[0001] The present invention relates to the technical field of composite plate structures, in particular to a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole and a design method thereof. Background Art

[0002] In the field of marine engineering, vibration and noise issues caused by the operation of electromechanical equipment have become a key technical bottleneck restricting ship comfort and equipment reliability. Vibration energy propagates through the hull structure to the cabin, causing not only physical fatigue and decreased concentration among crew members, but also potentially causing malfunctions in precision instruments, seriously impacting navigation safety. As ships grow larger and more power-dense, the increased power of main engines and the scale of mechanical equipment exacerbate the coupling effect of vibration and noise. Traditional vibration and noise reduction methods face the dual challenges of surging costs and limited efficiency.

[0003] As a cutting-edge technology in the field of vibration energy manipulation, the ideal acoustic black hole is one with a gradually changing edge thickness that satisfies the power law h(x) = ε·x. m free wedge-shaped structure (such as a plate, beam, etc.), where h(x) is the thickness of the acoustic black hole region at x, ε is a constant, and m is a positive rational number with m≥2. When the vertically incident bending wave propagates toward the edge of the wedge structure in the direction of gradually decreasing thickness, its cumulative phase tends to infinity near the edge of the structure, causing the bending wave to be unable to continue to propagate to the edge, thereby avoiding wave reflection. This mechanism causes the bending wave energy to be effectively concentrated in the tip edge region of the wedge structure, forming the so-called "acoustic black hole" effect. Furthermore, by rotating the one-dimensional acoustic black hole around the edge of the wedge structure, a two-dimensional acoustic black hole structure can be constructed. The "acoustic black hole" structure can concentrate the bending wave energy at the edge of the one-dimensional wedge structure or the center of the two-dimensional acoustic black hole, effectively suppressing vibration. Because in actual manufacturing, it is difficult to achieve a structure thickness that strictly changes to zero according to a power law, and truncation is easily formed at the tip. Studies have shown that a very small local thickness can also cause the reflection coefficient of the structure to increase sharply, weakening its energy concentration effect. Pasting damping materials in the acoustic black hole area can effectively reduce the reflection coefficient. Pasting a high-density mass block as an oscillator in the center area of ​​the acoustic black hole can effectively absorb and dissipate the energy gathered by the acoustic black hole, further achieving the effect of reducing vibration and noise.

[0004] Phononic crystals are a new physical concept proposed in the field of condensed matter physics based on research on photonic crystals. Locally resonant phononic crystals possess a low-frequency band gap, effectively attenuating vibrations within the band gap, offering significant advantages in low-frequency vibration reduction applications. However, the band gap of locally resonant phononic crystals is concentrated in a very narrow frequency range, making it difficult to achieve good results in multiple bands simultaneously. The attenuation of vibrations within the band gap is affected by the structure of the phononic crystal. Existing phononic crystal isolators, limited by thickness, offer less than ideal vibration isolation at smaller periods, and the frequency range of the isolation is difficult to adjust.

[0005] Patent application number CN111851332A discloses a trackside sound barrier based on acoustic black holes. This solution utilizes the acoustic black hole effect to reduce wheel-rail noise to a certain extent without changing the track structure, achieving certain energy absorption and noise reduction effects. However, relying solely on damping materials attached to the black hole area has limited effect on dissipating the vibration energy accumulated at the center of the acoustic black hole. In particular, due to the presence of truncation, the undissipated energy at the center of the acoustic black hole is reflected, limiting the vibration and noise reduction effect. Furthermore, the effective vibration and noise reduction frequency band of a plate structure using only one set of acoustic black holes is limited, affecting only certain mid- and high-frequency bands.

[0006] To sum up, how to effectively suppress wide-band vibration noise and achieve efficient sound insulation has become a core technical problem that needs to be solved urgently in this field. Summary of the Invention

[0007] The purpose of the present invention is to provide a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole and a design method thereof in order to solve at least one of the above technical problems.

[0008] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0009] A ship cabin sound insulation and vibration reduction partition containing an acoustic black hole, comprising: an acoustic black hole thin plate layer, a damping material layer, and a honeycomb plate layer;

[0010] A plurality of acoustic black hole structures are arranged in an array on the acoustic black hole thin plate layer, and the thickness of the acoustic black hole region satisfies a power law;

[0011] The damping material layer is used to form an energy buffer interface, and two sides of the damping material layer are respectively connected to the acoustic black hole thin plate layer and the honeycomb plate layer;

[0012] The honeycomb panel layer is used to achieve acoustic radiation impedance matching suppression.

[0013] Furthermore, a high-density oscillator with a radius of R1 and a damping material with a radius of R2 are coaxially attached to the center of the acoustic black hole region of the acoustic black hole thin plate layer, and R1<R2.

[0014] Furthermore, the high-density oscillator material is copper, the damping material is polymer, and the high-density oscillator material and the damping material are combined to form a local resonance type phononic crystal cell unit.

[0015] Furthermore, the acoustic black hole structure is provided with two groups, the two groups of acoustic black hole radii are different and the two groups of acoustic black hole center distances are different.

[0016] Furthermore, the two groups of acoustic black holes are arranged at intervals.

[0017] Furthermore, the damping material layer is an aerogel felt layer.

[0018] Furthermore, the honeycomb board layer includes: a thin board layer and a honeycomb layer;

[0019] The honeycomb layer is composed of honeycombs with a regular hexagonal cavity structure, and the cavities of the honeycombs are filled with damping filling material.

[0020] Furthermore, the thickness of the thin plate layer is 1 / 5 of the thickness of the honeycomb layer;

[0021] The honeycomb height of the honeycomb is greater than twice the thickness of the honeycomb plate layer.

[0022] Furthermore, the thickness of the damping material layer is not less than twice the thickness of the acoustic black hole thin plate layer.

[0023] Furthermore, the acoustic black hole thin plate layer, the damping material layer and the honeycomb plate layer are all the same in size and shape.

[0024] A method for designing a sound-insulating and vibration-damping partition for a ship cabin containing an acoustic black hole, for manufacturing any of the above-described sound-insulating and vibration-damping partitions for a ship cabin containing an acoustic black hole, the method comprising the following steps:

[0025] The vibration and noise signals of the sound source are measured by a vibration and noise test system, and the measurement results are analyzed to obtain basic data; based on the basic data, the starting frequency of the required acoustic black hole and the minimum frequency that meets the smoothness requirements are determined;

[0026] Based on the starting frequency and the lowest frequency that meets the smoothness requirement, and in combination with the usage scenario of the partition, a minimum radius r of the acoustic black hole is determined;

[0027] Using the minimum radius r as the minimum value and a step size of 0.1 m, establish at least three sets of acoustic black hole thin plate models using finite element software for calculation, and select at least two target calculation examples from the acoustic black hole thin plate models whose effective frequency bands correspond to the positions of the acoustic vibration line spectra of the sound source; determine the radius of each set of acoustic black holes based on the target calculation examples;

[0028] The thickness R0 of the damping material attached to the center of the acoustic black hole region is obtained based on the following formula;

[0029]

[0030] Where ω is the frequency; ρ is the density of the acoustic black hole plate; v is the Poisson's ratio of the acoustic black hole plate; ε is the power law h(x) = ε·x m The coefficient of E is the Young's modulus of the acoustic black hole plate; R t is the cutoff radius; R i is the radius of the acoustic black hole; η comp (r) is the equivalent loss factor; r is the radius of the required acoustic black hole; η D is the loss factor of the damping material; E D is the Young's modulus of the damping material; h D is the thickness of the damping layer; E w is the complex elastic modulus of the acoustic black hole structure; h w is the thickness of the acoustic black hole region;

[0031] Based on the principle of local resonance phononic crystals, the array distance of each group of acoustic black hole structures is determined under the premise of being able to weaken the sound source and amplitude of the low-frequency area to a preset degree;

[0032] Based on the thickness of the acoustic black hole thin plate layer, the thickness of the damping material layer and the honeycomb panel layer are designed according to the cabin space size and sound insulation requirements, while occupying as little cabin space as possible.

[0033] The beneficial effects of the present invention are:

[0034] The present invention achieves efficient control of wide-band noise by synergistically integrating the acoustic black hole effect, the local resonance phononic crystal mechanism, damping energy consumption, and honeycomb sound insulation technology. Through the energy focusing network constructed by multiple sets of variable parameter acoustic black hole arrays, combined with the local resonance unit formed by the central copper oscillator and the peripheral damping material, the vibration energy in the frequency band above 500Hz is efficiently converted, and the vibration amplitude in the frequency band of 300-500Hz is effectively suppressed; the asymmetric periodic phononic crystal layout enables the low-frequency sound insulation to break through the bottleneck of traditional acoustic black hole technology and achieve improved sound insulation in the low-frequency band; the composite impedance matching design of the aerogel felt layer and the filled honeycomb structure improves the airborne sound insulation in the entire frequency band, while the nanoporous structure of the aerogel felt gives the partition fireproof properties. The present invention breaks through the frequency band limitation of a single noise reduction method through the multi-physical field coupling mechanism, and is particularly suitable for engineering scenarios such as ship cabins that have complex requirements for fire prevention, lightweighting, and wide-band noise reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic side view of a sound insulation and vibration reduction partition structure for a ship cabin containing an acoustic black hole according to one embodiment of the present invention;

[0036] Figure 2 This is a front view schematic diagram of a sound insulation and vibration reduction partition structure for a ship cabin containing an acoustic black hole according to one embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of an acoustic black hole thin plate layer according to one embodiment of the present invention;

[0038] Figure 4 This is an enlarged schematic diagram of an acoustic black hole according to one embodiment of the present invention;

[0039] Figure 5 Schematic diagram of a damping material layer according to an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of a honeycomb panel layer according to an embodiment of the present invention;

[0041] Figure 7 This is a cross-sectional view of a local resonance type phononic crystal cell unit according to one embodiment of the present invention;

[0042] Figure 8 This is a flow chart of a design method for a sound-insulating and vibration-damping partition for a ship cabin containing an acoustic black hole according to one embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention will now be discussed with reference to exemplary embodiments. It should be understood that the embodiments discussed are only intended to enable those skilled in the art to better understand and implement the present invention, rather than to imply any limitation on the scope of the present invention.

[0044] As used herein, the term "including" and variations thereof are to be interpreted as open-ended terms meaning "including, but not limited to." The term "based on" is to be interpreted as "based, at least in part, on." The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment."

[0045] Example 1

[0046] Figure 1 A schematic side view of a sound insulation and vibration reduction partition structure for a ship cabin containing an acoustic black hole according to one embodiment of the present invention; Figure 2 This is a front view schematic diagram of a sound insulation and vibration reduction partition structure for a ship cabin containing an acoustic black hole according to one embodiment of the present invention; Figure 3 This is a schematic diagram of an acoustic black hole thin plate layer according to one embodiment of the present invention; Figure 4 This is an enlarged schematic diagram of an acoustic black hole according to one embodiment of the present invention; Figure 5 Schematic diagram of a damping material layer according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a honeycomb panel layer according to an embodiment of the present invention; Figure 7This is a cross-sectional view of a local resonance type phononic crystal cell unit according to an embodiment of the present invention. Figure 1-7 As shown, according to one embodiment of the present invention, a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole comprises: an acoustic black hole thin plate layer 1, a damping material layer 2, and a honeycomb plate layer 3;

[0047] A plurality of acoustic black hole structures are arranged in an array on the acoustic black hole thin plate layer 1, and the thickness of the acoustic black hole region satisfies a power law;

[0048] The damping material layer 2 is used to form an energy buffer interface, and the two sides of the damping material layer 2 are connected to the acoustic black hole thin plate layer 1 and the honeycomb plate layer 3 respectively;

[0049] The honeycomb panel layer 3 is used to achieve impedance matching and suppression of acoustic radiation.

[0050] Preferably, the acoustic black hole thin plate layer 1 , the damping material layer 2 and the honeycomb plate layer 3 are of the same size and shape.

[0051] This embodiment proposes a ship cabin sound insulation and vibration damping partition containing an acoustic black hole. This structure achieves vibration and noise control within the ship cabin through the synergistic effect of multiple functional materials. The structure is composed of a laminated acoustic black hole layer 1, a damping material layer 2, and a honeycomb panel layer 3. Each layer is conformally connected through physical or chemical means to form an acoustic-vibration coupling suppression system with gradient impedance characteristics.

[0052] The acoustic black hole thin plate layer 1 adopts an array power law thickness distribution design. Its core principle is to use the structure thickness to follow the power function (h(x) = ε·x m , m≥2) continuously decreases to form an acoustic black hole effect. The acoustic black hole thin plate layer 1 includes a region with uniform thickness and an acoustic black hole region. When the vibration wave or sound wave propagates in the acoustic black hole thin plate layer 1 to the acoustic black hole region, the group velocity of the wave gradually decreases as the thickness decreases, resulting in a cumulative effect of energy at the end of the black hole. This geometric structure feature enables the incident wave to achieve energy focusing on the propagation path, and the effective action frequency band can be expanded in conjunction with the array arrangement. While maintaining the overall stiffness, the structure can realize the redistribution of vibration energy in a specific frequency band (usually medium and high frequencies) by regulating the wave propagation path.

[0053] Damping material layer 2 acts as an energy conversion interface, converting mechanical vibration energy into heat through a viscoelastic damping mechanism. Its shear deformation properties, combined with the strain concentration effect of the black hole structure, create coupled dissipation, effectively breaking the energy transfer chain from structural vibration to acoustic radiation. The introduction of damping material layer 2 reduces the system's quality factor and significantly shortens the vibration decay time constant.

[0054] The honeycomb panel layer 3 utilizes a micro-perforated honeycomb core structure. Its multi-channel network of hexagonal cells enables multiple scattering and viscous losses of sound waves. This layer achieves acoustic radiation impedance matching through geometric topology optimization. Its characteristic impedance lies between that of the fluid medium (air / water) and the solid structure, reducing the reflection coefficient of sound waves at the interface. The low bending stiffness of the honeycomb structure also provides additional vibration decoupling, forming a stiffness gradient transition with the upper damping material layer 2, preventing secondary noise radiation caused by sudden changes in material parameters.

[0055] This invention utilizes gradient impedance design across each functional layer to construct a complete acoustic-vibration control chain encompassing "vibration capture, energy dissipation, and acoustic impedance matching." The acoustic black hole layer achieves spatial energy redistribution, the damping material layer transforms energy, and the honeycomb panel layer absorbs acoustic waves. The synergistic effect of these three elements simultaneously suppresses the propagation of structure-borne and airborne noise. This invention improves sound insulation without increasing system mass, making it particularly suitable for weight-sensitive applications such as ship cabins that require broadband noise reduction.

[0056] According to one embodiment of the present invention, a high-density oscillator with a radius of R1 and a damping material with a radius of R2 are coaxially attached to the center of the acoustic black hole region of the acoustic black hole thin plate layer 1, and R1 < R2.

[0057] Preferably, the high-density oscillator material is copper, the damping material is polymer, and the high-density oscillator material and the damping material are combined to form a local resonance type phononic crystal cell unit.

[0058] In this embodiment, building on the geometric sound-absorbing structure of the acoustic black hole thin plate layer 1, a localized resonant phononic crystal cell unit is introduced, forming a multi-level vibration energy regulation mechanism. This structure coaxially nests a high-density copper oscillator and a polymer damping ring in the center of the acoustic black hole region. The density of the high-density oscillator is higher than that of the damping material, and the thickness of the upper high-density oscillator is equal to or greater than that of the lower low-density damping material. A mass-spring-damper composite system is constructed through a dimensional design with R1 < R2. The copper oscillator acts as a local resonator, providing inertial mass. Its radius R1 precisely matches the minimum thickness region at the end of the acoustic black hole, utilizing the material density difference to form a significant acoustic impedance abrupt interface. The peripheral polymer damping ring, with its R2 > R1 overlay design, acts as a constrained damping layer to absorb the copper oscillator's vibration energy and also serves as the elastic matrix of the phononic crystal. Its low shear modulus effectively prolongs the vibration decay time constant.

[0059] Wideband vibration control is achieved through the synergistic effect of the acoustic black hole effect and the local resonance mechanism: the power-law thickness distribution of the acoustic black hole causes the incident wave to produce progressive energy accumulation during propagation. When the wavefront reaches the center of the black hole, the high-density copper oscillator converts the macroscopic vibration into microscopic particle displacement through the mass loading effect, triggering the viscoelastic dissipation mechanism of the polymer damping ring; at the same time, the density difference between the copper oscillator and the matrix material forms a Bragg scattering interface, which couples with the local resonance mode to produce a bandgap regulation effect, allowing the system to extend the effective sound insulation frequency band to low frequencies while maintaining structural compactness.

[0060] The composite control mechanism of the present invention has three technical advantages: (1) Enhanced energy focusing effect: The geometric sound absorption of the acoustic black hole and the mass vibration absorption of the local resonance form a dual energy capture, which improves the concentration of vibration energy; (2) Optimized frequency response characteristics: By adjusting the ratio of the copper oscillator radius R1 to the damping material radius R2, the band gap center frequency can be customized to cover the fundamental frequency of the ship's main engine vibration and its harmonic components; (3) Enhanced structural stability: The radial constraint effect of the damping material can suppress the displacement of the copper oscillator under high-frequency vibration, avoiding the fatigue failure problem that is prone to occur in traditional local resonance structures. The present invention provides an innovative solution for the control of low-frequency line spectrum noise in ship cabins through the deep integration of geometric sound absorption and dynamic vibration absorption.

[0061] According to one embodiment of the present invention, two groups of acoustic black hole structures are provided, the two groups of acoustic black hole radii are different and the two groups of acoustic black hole center distances are different.

[0062] Preferably, the two groups of acoustic black holes are arranged at intervals.

[0063] In this embodiment, a multi-band vibration energy collaborative control mechanism is constructed by setting two groups of acoustic black hole structures with different geometric parameters on the acoustic black hole thin plate layer 1. The core of this technical solution lies in the use of an asymmetric periodic arrangement strategy: the first group of acoustic black holes is designed with a large radius r1, and the center spacing D1 of the circles meets the wavelength scale, mainly for regulating low-frequency structure noise; the second group of acoustic black holes is designed with a small radius r2 (r2<r1), and the center spacing D2 (D2≠D1) is optimized to match the wavelength characteristics of air noise in the medium and high frequency bands. The two groups of acoustic black hole structures are arranged in an interlaced manner to form a two-dimensional periodic lattice, and the decoupling control of broadband vibration modes is achieved through the spatial Fourier transform characteristics.

[0064] The power-law thickness distribution of the large-radius acoustic black hole effectively reduces the phase velocity of low-frequency bending waves, causing long-wavelength vibrations to produce significant phase delays in the structure. The small-radius acoustic black hole, through its high-curvature surface, enhances the scattering effect of medium- and high-frequency sound waves. The asymmetric center-to-center distance design overcomes the Bragg scattering conditions of traditional periodic structures, avoiding the sound insulation dips caused by modal superposition. In particular, by optimizing the ratio of D1 to D2, a staggered arrangement of low-frequency resonance peaks and high-frequency antiresonance peaks can be achieved. The staggered arrangement of the two groups of acoustic black holes forms a multi-scale energy well network. After the incident wave undergoes initial attenuation in the first-stage large-radius black hole, the residual energy undergoes secondary focusing in the second-stage small-radius acoustic black hole region. Combined with the viscoelastic dissipation of the damping material layer 2, this forms a cascaded energy attenuation channel.

[0065] Through the combination of dual-mode parameters, the present invention broadens the effective frequency band of the traditional single-mode acoustic black hole to two orders of magnitude, especially in the control of the fundamental frequency of the ship's main engine and its harmonic components; the asymmetric arrangement makes the structure have different impedance characteristics in the radial and tangential directions, and can be customized according to the direction of the propeller excitation force in the ship's cabin; compared with a single large-size acoustic black hole structure, the dual-mode layout reduces the total mass while maintaining the sound insulation performance, which is more in line with the lightweight design requirements of ships.

[0066] According to one embodiment of the present invention, the damping material layer 2 is an aerogel felt layer.

[0067] Preferably, the aerogel felt layer is attached between the acoustic black hole sheet layer 1 and the honeycomb sheet layer 3 in an adhesive manner.

[0068] In this embodiment, aerogel felt is used as the damping material layer 2. Its unique nanoporous structure forms a viscoelastic constrained damping system with the acoustic black hole sheet layer 1 and the honeycomb sheet layer 3. The aerogel felt layer achieves conformal interface bonding through full-plane bonding. Its highly porous nanoskeleton effectively disperses the vibration energy focused by the acoustic black hole structure, achieving energy conversion through a dual mechanism of viscous air loss between pores and shear deformation of the polymer matrix. While maintaining an ultra-low density, this material's damping temperature range can be regulated by varying the pore structure parameters, maintaining a stable loss factor over a wide temperature range. Its three-dimensional, interconnected nanonetwork structure also suppresses flexural wave reflections from the honeycomb sheet layer 3, creating multiple acoustic scattering pathways.

[0069] The aerogel felt layer of the present invention improves the sound insulation of the partition and reduces the structural surface density; its nano-damping characteristics shorten the vibration attenuation time constant and significantly suppress high-frequency continuous spectrum noise in the ship cabin.

[0070] According to one embodiment of the present invention, the honeycomb plate layer 3 includes: a thin plate layer and a honeycomb layer;

[0071] The honeycomb layer is composed of honeycombs with a regular hexagonal cavity structure, and the cavities of the honeycombs are filled with damping filling materials.

[0072] Preferably, the thickness of the thin plate layer is 1 / 5 of the thickness of the honeycomb layer;

[0073] The honeycomb height of the honeycomb is greater than twice the thickness of the honeycomb plate layer 3.

[0074] In this embodiment, the structure of the honeycomb plate layer 3 is further described. The honeycomb plate layer 3 is a filled honeycomb damping composite structure. By setting a regular hexagonal cavity honeycomb layer in the honeycomb plate layer 3 and injecting a polymer damping filling material into the honeycomb cavity, a "rigid skeleton-flexible damping" composite system is formed. The honeycomb height of the honeycombs constituting the honeycomb layer is greater than twice the thickness of the honeycomb plate layer 3. Its regular hexagonal topological structure provides isotropic bending stiffness, while the polymer filler in the cavity absorbs structural vibration energy through a viscoelastic deformation mechanism, especially producing a significant shear dissipation effect during the deformation of the honeycomb wall. The combined structure of the thin plate layer and the honeycomb layer transfers interfacial stress, so that the damping filling material is always in the efficient working strain zone. At the same time, the honeycomb height design can effectively extend the propagation path of the sound wave in the microporous structure and enhance the viscous loss effect.

[0075] The honeycomb panel layer design of the present invention improves the sound insulation of the partition while reducing the surface density; the damping filling design increases the critical buckling load of the honeycomb structure, significantly enhancing the structural stability under complex sea conditions.

[0076] According to one embodiment of the present invention, the thickness of the damping material layer 2 is not less than twice the thickness of the acoustic black hole thin plate layer 1 .

[0077] In this embodiment, the performance optimization of the acoustic-vibration coupling system is achieved by precisely controlling the thickness parameters of each layer, wherein the damping material layer 2 is designed to be twice or more thick than the acoustic black hole thin plate layer 1, and the nonlinear relationship between the strain energy density and thickness of the viscoelastic material is utilized. Under the premise of maintaining the interface shear stress matching, the working strain zone of the damping layer is extended to the high strain gradient area at the end of the black hole structure, thereby significantly improving the efficiency of the constrained damping treatment; the honeycomb height of the honeycomb plate layer 3 exceeds the extended structure of twice the thickness of the honeycomb plate layer 3 to form a gradient impedance interface, and through the coupling of the cavity resonance effect and the film vibration mode, multiple sound wave scattering paths are generated during the bending deformation of the honeycomb wall, while maintaining the structural surface density comparable to that of the traditional scheme.

[0078] The thickness matching design of the present invention improves the sound insulation of the partition, the thickness optimization of the damping material layer improves the vibration energy dissipation efficiency, and the honeycomb height design reduces the sound radiation efficiency while maintaining the structural rigidity. It is particularly suitable for the dual needs of lightweight and efficient noise reduction in ship cabins.

[0079] The present invention uses a combination of acoustic black holes, local resonant phononic crystals, and other means, combined with a damping sound-absorbing layer and a honeycomb panel sound insulation layer, to significantly reduce vibration and noise within a wide frequency range, achieving a highly efficient sound insulation effect.

[0080] Example 2

[0081] like Figure 1-7 According to one embodiment of the present invention, a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole is used to separate the cabins of the ship and isolate the sound transmission between the cabins, including: an acoustic black hole thin plate layer 1, a damping material layer 2 and a honeycomb plate layer 3.

[0082] The acoustic black hole thin plate layer 1 consists of an acoustic black hole region and a uniform region, with a high-density mass block and damping material attached to the center of the acoustic black hole. The acoustic black hole thin plate layer 1 is made of aluminum alloy and has a rectangular shape. The thickness of the acoustic black hole region satisfies the power law: h(x) = εx m The acoustic black hole area is gradually decreasing, and there is a cutoff at the center of the acoustic black hole with a thickness of 0.5mm. A high-density oscillator is attached to the center of the acoustic black hole area, and a damping material is attached to the acoustic black hole area around the high-density oscillator.

[0083] The two groups of acoustic black holes in acoustic black hole sheet layer 1 have different radii. The center distance within each group of acoustic black hole regions is constant, and the holes are arranged in a rectangular array. The acoustic black holes are manufactured by stamping or 3D printing. The high-density oscillators in the center of the acoustic black hole region are made of copper. The area filled with the high-density oscillators has a radius of 0.008m and a thickness of 0.001m. The high-density oscillators are attached to the center of the acoustic black hole region by adhesive bonding. The additional damping material in the center of the acoustic black hole region is a polymer. The damping material has a radius of 0.08m and a thickness of 0.001m and is attached to the acoustic black hole region by adhesive bonding.

[0084] The damping material layer 2 is made of aerogel felt. Its shape and size are consistent with those of the acoustic black hole sheet layer 1, and its thickness is twice that of the acoustic black hole sheet layer 1. The damping material layer 2 made of aerogel felt is attached between the acoustic black hole sheet layer 1 and the honeycomb panel layer 3 by gluing.

[0085] The honeycomb panel layer 3 is composed of honeycomb panels and damping filling materials.

[0086] The honeycomb plate layer 3 includes a thin plate layer and a honeycomb layer. The thickness of the thin plate layer is 1 / 5 of the thickness of the honeycomb layer. The honeycombs of the honeycomb layer are filled with damping filling material.

[0087] The honeycomb plate layer 3 is composed of a honeycomb layer and a thin plate layer, which are connected by welding. The honeycombs forming the honeycomb layer are regular hexagonal cavities, which are filled with a damping filling material, which is a polymer.

[0088] This embodiment proposes a ship cabin sound insulation and vibration reduction diaphragm containing an acoustic black hole, integrating a multi-dimensional vibration control mechanism. The diaphragm utilizes a three-layer composite structure to achieve full control from vibration energy capture to acoustic radiation suppression. The diaphragm is composed of an acoustic black hole thin plate layer (1), a damping material layer (2), and a honeycomb panel layer (3). These layers form a synergistic system through physical coupling.

[0089] Acoustic black hole sheet layer 1 utilizes an aluminum alloy substrate to construct a dual-mode acoustic black hole array. Acoustic black hole sheet layer 1 consists of a uniform region and an acoustic black hole region with a power-law gradient thickness. The acoustic black hole region retains a 0.5mm process cutoff at the end of the wedge-shaped structure to avoid processing defects. To compensate for energy reflection caused by the cutoff, a dual-component energy processing system is integrated into the center of the black hole: a 16mm diameter, 1mm thick copper high-density vibrator is embedded in the center, absorbing vibration energy in a specific frequency band through a local resonance mechanism; a 160mm diameter, 1mm thick polymer damping material ring is placed around the high-density vibrator, converting residual mechanical energy into heat through a viscoelastic dissipation mechanism. Two groups of acoustic black hole units with different radii (the radius difference is designed based on the typical vibration frequency distribution of ships) are periodically arranged in a rectangular array. The unit spacing is optimized to avoid modal coupling. This asymmetric layout can expand the effective operating frequency band.

[0090] Damping material layer 2 utilizes aerogel felt to create an energy buffer interface. Its thickness is designed to be twice that of the acoustic black hole sheet layer 1 to provide ample deformation space. This layer achieves broadband damping characteristics through its molecular-level pore structure, forming a viscous damping field within the vibration transmission path. Specifically, a special adhesive chemically bonds the aerogel felt layer to the upper and lower layers, ensuring that vibration energy is transferred between the layers without generating secondary noise due to interfacial slip.

[0091] The honeycomb panel layer 3, serving as an acoustic radiation barrier, utilizes a regular hexagonal honeycomb sandwich structure, with its equivalent density controlled by the honeycomb's geometric parameters. The honeycomb cavities are filled with a polymer damping filler material, forming a mass-spring-damper composite system: the honeycomb walls act as elastic elements, while the cavity damping material dissipates energy. This combined structure reduces weight while maintaining structural rigidity. The honeycomb layer and the thin plate layer are metallurgically bonded via laser welding, with the weld points arranged in a honeycomb pattern to balance stress distribution.

[0092] This invention utilizes a multi-physics coupling mechanism: an acoustic black hole thin plate layer first spatially focuses vibration energy through geometric gradients. High-density oscillators selectively absorb this focused energy in the frequency domain. Residual energy is viscously dissipated by the damping material layer, and finally, the honeycomb plate layer achieves impedance matching and suppression of acoustic radiation. This cascaded energy processing process overcomes the frequency band limitations of traditional single-layer structures, achieving full-link vibration control from flexural wave manipulation to acoustic radiation suppression while maintaining structural compactness.

[0093] Example 3

[0094] Figure 8 This is a flow chart of a design method for a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole according to an embodiment of the present invention. Figure 8 As shown, according to one embodiment of the present invention, a design method for a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole is used to manufacture any ship cabin sound insulation and vibration reduction partition containing an acoustic black hole of the present invention, and the method comprises the following steps:

[0095] Step S102: measuring the vibration and noise signals of the sound source using a vibration and noise testing system, and analyzing the measurement results to obtain basic data; based on the basic data, determining the starting frequency of the required acoustic black hole and the minimum frequency that meets the smoothness requirement;

[0096] Step S104 : Based on the starting frequency and the lowest frequency that meets the smoothness requirement, the minimum radius r of the required acoustic black hole is determined in combination with the partition usage scenario.

[0097] Step S106: Using finite element software to establish at least three acoustic black hole thin plate models with a minimum radius r as the minimum value and a step size of 0.1 m, and selecting at least two target calculation examples from the acoustic black hole thin plate models whose effective frequency bands correspond to the positions of the acoustic vibration line spectra of the sound source; determining the radius of each acoustic black hole based on the target calculation examples;

[0098] Step S108, obtaining the thickness R0 of the damping material attached to the center of the acoustic black hole region based on the following formula;

[0099]

[0100] Where ω is the frequency; ρ is the density of the acoustic black hole plate; v is the Poisson's ratio of the acoustic black hole plate; ε is the power law h(x) = ε·x m The coefficient of E is the Young's modulus of the acoustic black hole plate; R t is the cutoff radius; R i is the radius of the acoustic black hole; η comp (r) is the equivalent loss factor; r is the radius of the required acoustic black hole; η D is the loss factor of the damping material; E Dis the Young's modulus of the damping material; h D is the thickness of the damping layer; E w is the complex elastic modulus of the acoustic black hole structure; h w is the thickness of the acoustic black hole region;

[0101] Step S110, based on the principle of local resonance phononic crystals, the array distance of each group of acoustic black hole structures is determined under the premise of being able to weaken the sound source in the low-frequency region and the preset degree of amplitude;

[0102] Step S112 , based on the thickness of the acoustic black hole thin plate layer 1 , and in accordance with the cabin space size and sound insulation requirements, the thickness of the damping material layer 2 and the thickness of the honeycomb panel layer 3 are designed while occupying as little cabin space as possible.

[0103] In this implementation, a design method for a ship cabin sound insulation and vibration damping partition containing an acoustic black hole is proposed. Customized acoustic and vibration control is achieved through multi-physics field coupling analysis and parameter optimization. This method first uses a vibration and noise test system to perform a full-band scan of the target sound source (mechanical equipment), obtaining vibration acceleration levels and noise spectrum characteristics. Based on this, the start and end frequency boundaries of the acoustic black hole structure are determined. A finite element model cluster is established based on power-law thickness distribution theory, generating multiple sets of radius parameterized models with a step size of 0.1 m. Modal analysis and harmonic response calculations are then used to screen candidate solutions whose overlap with the sound source line spectrum exceeds a set threshold. The optimal damping layer thickness is calculated using an equivalent loss factor model, combining the dynamic mechanical parameters of the damping material to ensure phase matching between viscoelastic dissipation and structural vibration. Localized resonant phononic crystal theory is introduced, and band structure calculations are used to determine the periodic parameters of the acoustic black hole array, resulting in coupled suppression of the Bragg scattering band gap and the target low-frequency resonance peak. Finally, a multi-objective optimization model is established based on cabin space constraints to achieve coordinated optimization of structural thickness and surface density while ensuring sound insulation.

[0104] The present invention uses a data-driven forward design process to achieve deep adaptation between the sound insulation structure and the sound source characteristics. While maintaining the lightweight level of traditional solutions, it expands the effective frequency band of the acoustic black hole, especially improving the low-frequency line spectrum suppression capability through array period regulation; parametric modeling and multi-objective optimization technology shorten the design cycle, which is particularly suitable for the customized noise reduction needs of complex acoustic environments such as ship power systems.

[0105] Example 4

[0106] According to one embodiment of the present invention, a method for designing a sound insulation and vibration reduction partition for a ship cabin containing an acoustic black hole comprises the following steps:

[0107] In step S201 , the vibration and noise signals of the sound source (mechanical equipment) are measured using a vibration and noise testing system, and their characteristics are summarized to facilitate targeted design of the partition structure.

[0108] Step S202: Determine the minimum frequency of the sound and vibration signals to be solved and the starting frequency ω of the acoustic black hole required based on the sound and vibration characteristics of the sound source. c1 To make the acoustic black hole meet the smoothness requirement, it must be smaller than this value: ω≥ω c2 , determine the appropriate coefficient ε.

[0109] in,

[0110] Where h is the thickness of the acoustic black hole uniform region; E is the Young's modulus of the acoustic black hole plate; ρ is the density of the acoustic black hole plate; v is the Poisson's ratio of the acoustic black hole plate; ε is the power law h(x) = ε·x m The coefficient of ε is a constant; ω c1 is the starting frequency; ω c2 The minimum frequency that meets the smoothness requirement.

[0111] Step S203, according to the acoustic black hole principle and the required ω c1 and ω c2 The size of the acoustic black hole is used to calculate the radius r of the required acoustic black hole.

[0112] In step S204, the acoustic black hole radius r determined in step S203 is used as the minimum value, and the step size is 0.1 m. Finite element software is used to establish at least three sets of acoustic black hole thin plate models for calculation, and at least two sets of calculation examples are selected from them, whose effective frequency bands correspond to the frequency bands with larger amplitudes of the acoustic vibration line spectrum of the sound source.

[0113] Step S205 , according to the selected calculation example, select appropriate r1 and r2 as the radii of the two groups of acoustic black holes in the acoustic black hole thin plate layer 1 .

[0114] Step S206: Select a suitable damping layer thickness according to the following formula:

[0115]

[0116] Among them, R t is the cutoff radius, R i is the acoustic black hole radius. comp (r) is the equivalent loss factor, which is calculated using the following formula:

[0117]

[0118] Among them, E D is the Young's modulus of the damping material, h D is the thickness of the damping layer, ηD is the loss factor of the damping material, E w is the complex elastic modulus of the acoustic black hole structure, h w is the thickness of the acoustic black hole region.

[0119] Step S207, based on the principle of local resonance phononic crystal, the relative distance of the acoustic black hole structure array is determined under the premise of being able to weaken the sound source below the cutoff frequency of the acoustic black hole structure and the low-frequency noise with high amplitude.

[0120] Step S208: Based on the cabin space size and sound insulation requirements, the thickness of the damping layer and the honeycomb panel layer are designed while occupying as little cabin space as possible. In principle, the thickness of the damping layer should not be less than twice that of the acoustic black hole panel.

[0121] This invention achieves full-band coordinated control of vibration noise through multi-physics field coupling design. Its technical advantages are reflected in the following aspects:

[0122] Frequency-domain adaptive vibration energy manipulation: Based on the power-law thickness gradient structure of the acoustic black hole, the energy focusing effect of the bending waves in the medium and high frequency bands above 500Hz is achieved. Through the design of a dual-mode acoustic black hole array (radii r1 and r2 correspond to different characteristic frequencies), the operating frequency band of each group of black hole units is accurately matched with the line spectrum frequency of typical sound sources such as the ship's main engine and auxiliary engine. The high-density copper vibrator serves as a local resonance unit, and its natural frequency is optimized to absorb the specific frequency band energy gathered by the acoustic black hole, while the polymer damping ring processes the residual mechanical energy through the viscoelastic dissipation mechanism, forming a hierarchical processing chain of "energy capture-frequency band screening-mechanical dissipation".

[0123] Low-frequency bandgap expansion mechanism: For the low-frequency band below 300 Hz, a local resonant phononic crystal is constructed through a periodic array of acoustic black hole structures, so that Bragg scattering and local resonance effects produce a coupled bandgap, effectively compensating for the performance limitations of a single black hole structure in the low-frequency band.

[0124] Multi-level damping and dissipation system: The aerogel felt damping layer achieves broadband damping characteristics through a microscopic porous structure, ensuring continuous viscous dissipation. The honeycomb panel layer adopts a regular hexagonal honeycomb sandwich structure, which achieves secondary energy dissipation through polymer damping filling while ensuring structural rigidity. This three-level damping system (local damping ring-interlayer damping layer-honeycomb damping core) significantly improves structural damping compared to traditional partition structures. In terms of space constraints, the total thickness is controlled to meet the installation specifications of ship cabin partitions. The aerogel felt layer has fireproof and heat-insulating functions, further improving the performance of the partition.

[0125] The present invention comprehensively utilizes the acoustic black hole principle effect, the local resonance phononic crystal principle, the damping sound insulation and the honeycomb sound insulation principle, and can effectively and significantly reduce noise in low, medium and high frequency bands.

[0126] By setting up multiple groups of acoustic black hole structures, the vibration noise energy of each frequency band is effectively gathered, and the gathered energy is dissipated by using high-density mass blocks as oscillators and pasting damping materials. It has an outstanding effect on reducing vibration noise above 500Hz and has a significant effect on reducing vibration noise within 300Hz-500Hz. By periodically arraying the acoustic black hole structures to form a local resonant phononic crystal structure, the shortcomings of the acoustic black hole structure in terms of poor low-frequency effect are compensated, so that the partition has a significant sound insulation effect over the entire frequency range. At the same time, the sound insulation effect of the aerogel felt layer and the honeycomb board layer is combined to further significantly reduce the amount of noise transmission. The presence of the aerogel felt layer makes the partition have a higher fire resistance, making it suitable for use as a sound insulation panel in ship cabins and other facilities and equipment where sound insulation is required, and has extremely high engineering application value.

[0127] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the method described above can refer to the corresponding process in the aforementioned partition embodiment, and will not be repeated here.

[0128] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

[0129] It should be understood that the size of the serial numbers of each step in the content of the invention and the embodiments of the present invention does not absolutely mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A ship cabin sound insulation and vibration reduction partition containing an acoustic black hole, characterized in that: include: Acoustic black hole thin plate layer (1), damping material layer (2), honeycomb plate layer (3); A plurality of groups of acoustic black hole structures are arranged in an array on the acoustic black hole thin plate layer (1), and the thickness of the acoustic black hole region satisfies a power law; The damping material layer (2) is used to form an energy buffer interface, and two sides of the damping material layer (2) are respectively connected to the acoustic black hole thin plate layer (1) and the honeycomb plate layer (3); The honeycomb plate layer (3) is used to achieve acoustic radiation impedance matching suppression.

2. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 1 is characterized in that: A high-density oscillator with a radius of R1 and a damping material with a radius of R2 are coaxially attached to the center of the acoustic black hole region of the acoustic black hole thin plate layer (1), and R1 < R2.

3. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 2 is characterized in that: The high-density oscillator material is copper, the damping material is polymer, and the high-density oscillator material and the damping material are combined to form a local resonance type phononic crystal cell unit.

4. The ship cabin sound insulation and vibration reduction partition containing an acoustic black hole according to claim 1, characterized in that: The acoustic black hole structure is provided with two groups, the radii of the two groups of acoustic black holes are different and the center distances of the two groups of acoustic black holes are different.

5. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 4 is characterized in that: The two groups of acoustic black holes are arranged at intervals.

6. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 1, characterized in that: The damping material layer (2) is an aerogel felt layer.

7. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 1 is characterized in that: The honeycomb plate layer (3) comprises: a thin plate layer and a honeycomb layer; The honeycomb layer is composed of honeycombs with a regular hexagonal cavity structure, and the cavities of the honeycombs are filled with damping filling material.

8. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 7 is characterized in that: The thickness of the thin plate layer is 1 / 5 of the thickness of the honeycomb layer; The honeycomb height of the honeycomb is greater than twice the thickness of the honeycomb plate layer (3).

9. The ship cabin sound insulation and vibration reduction partition containing acoustic black holes according to claim 1, characterized in that: The thickness of the damping material layer (2) is not less than twice the thickness of the acoustic black hole thin plate layer (1).

10. A design method for a ship cabin sound insulation and vibration reduction partition containing an acoustic black hole, used to manufacture the ship cabin sound insulation and vibration reduction partition containing an acoustic black hole as claimed in any one of claims 1 to 9, characterized in that: The method comprises the following steps: The vibration and noise signals of the sound source are measured by a vibration and noise test system, and the measurement results are analyzed to obtain basic data; based on the basic data, the starting frequency of the required acoustic black hole and the minimum frequency that meets the smoothness requirements are determined; Based on the starting frequency and the lowest frequency that meets the smoothness requirement, and in combination with the usage scenario of the partition, a minimum radius r of the acoustic black hole is determined; Using the minimum radius r as the minimum value and a step size of 0.1 m, establish at least three sets of acoustic black hole thin plate models using finite element software for calculation, and select at least two target calculation examples from the acoustic black hole thin plate models whose effective frequency bands correspond to the positions of the acoustic vibration line spectra of the sound source; determine the radius of each set of acoustic black holes based on the target calculation examples; The thickness R0 of the damping material attached to the center of the acoustic black hole region is obtained based on the following formula; Where ω is the frequency; ρ is the density of the acoustic black hole plate; ν is the Poisson's ratio of the acoustic black hole plate; ε is the power law h(x) = ε·x m The coefficient of E is the Young's modulus of the acoustic black hole plate; R t is the cutoff radius; R i is the radius of the acoustic black hole; η comp (r) is the equivalent loss factor; r is the radius of the required acoustic black hole; η D is the loss factor of the damping material; E D is the Young's modulus of the damping material; h D is the thickness of the damping layer; E w is the complex elastic modulus of the acoustic black hole structure; h w is the thickness of the acoustic black hole region; Based on the principle of local resonance phononic crystals, the array distance of each group of acoustic black hole structures is determined under the premise of being able to weaken the sound source and amplitude of the low-frequency area to a preset degree; Based on the thickness of the acoustic black hole thin plate layer (1), the thickness of the damping material layer (2) and the thickness of the honeycomb plate layer (3) are designed according to the cabin space size and sound insulation requirements while occupying as little cabin space as possible.

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