Anti-resonance panel and method of manufacturing the same

Abstract

The present invention relates to anti-resonance panels and methods of making the same. Exemplary methods, panels, and systems for providing sound insulation are disclosed. Sound insulation may be provided by an anti-resonance panel comprising a base panel comprising a base panel core and two base panel face sheets, wherein each of the two base panel face sheets is adjacent to opposite sides of the base panel core, respectively. The anti-resonance panel further comprises at least one stiffener member positioned along the base panel in a defined area of ​​the base panel, wherein the defined area is less than the entire area of ​​the base panel. The stiffener member comprises a stiffener member core and two stiffener member face sheets, wherein the stiffener member face sheets are adjacent to opposite sides of the stiffener member core.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate generally to soundproofing materials and, more particularly, to methods and systems for providing soundproofing using panels. Background Art

[0002] Current techniques for soundproofing use passive noise control methods such as absorbers, dampers or acoustic dampers. These components are typically either too large or too heavy, making these methods either ineffective for noise control or ineffective for low frequency noise control. Active noise control offers another noise control option. However, active noise control requires wiring and electricity, which can make active noise control complex, expensive and / or difficult to implement in applications where there are large surface areas (e.g., in motor vehicles, boats or aircraft) (e.g., "area noise control"). Summary of the invention

[0003] A soundproof panel is provided herein. The soundproof panel may be an anti-resonance panel, the anti-resonance panel comprising a base panel having a base panel core material and two base panel face sheets, wherein each of the two base panel face sheets is respectively adjacent to opposite sides of the base panel core material. The anti-resonance panel further comprises at least one reinforcement member positioned in a defined area of ​​the base panel along the base panel, wherein the defined area is less than the entire area of ​​the base panel. The reinforcement member comprises a reinforcement member core material and two reinforcement member face sheets. The two reinforcement member face sheets are respectively adjacent to opposite sides of the reinforcement member core material, and the reinforcement member is configured to provide anti-resonance performance to the base panel. The reinforcement member may be configured to provide anti-resonance performance to the base panel by increasing stiffness to the defined area of ​​the base panel with a low mass density. The reinforcement member may be arranged on one of the two base panel face sheets. The reinforcement member may be arranged between the two base panel face sheets and adjacent to the base panel core material. In some embodiments, the stiffener members may be disposed along less than 25% of the total surface area of ​​the base panel, and the mass of the stiffener members may be approximately 20% or less of the total mass of the anti-resonance panel.

[0004] In some embodiments, the anti-resonance panel may include two or more stiffener members, each stiffener member being positioned along the base panel in a respective defined area of ​​the base panel.

[0005] The reinforcement member core material may include polyethylene terephthalate (PET) foam, aramid honeycomb structure or a combination thereof. The reinforcement member face sheet may include carbon fiber, glass fiber or a combination thereof.

[0006] In some embodiments, the anti-resonance panel can reduce noise propagating through the anti-resonance panel at frequencies between about 300 Hz and about 1000 Hz.

[0007] In some embodiments, a perimeter stiffener member may be arranged along one or more edges of the stiffener member. In some embodiments, the stiffener member may include an inner wall defining a hollow portion in the stiffener member. In some embodiments, the anti-resonance panel may include at least one inertial member configured to provide a mass increase over the defined area of ​​the sandwich panel. The inertial member may have a mass density that is about 10 times the mass density of the stiffener member. The inertial member may include solid aluminum, rubber, tungsten, ceramic, or a combination thereof.

[0008] In some embodiments, the anti-resonance panel may include a reinforcement member. The reinforcement member may be arranged along the perimeter of the defined area of ​​the base panel and define an acoustic boundary for the defined area of ​​the base panel. In some embodiments, the anti-resonance panel may include a grounding member. The grounding member may be configured to anchor the anti-resonance panel to a structure and define an acoustic boundary for the defined area of ​​the base panel.

[0009] Embodiments provided herein may also relate to a method of manufacturing an anti-resonance panel. For example, the method may include attaching at least one stiffener member to a base panel, wherein the base panel includes a base panel core material and two base panel face sheets. Each of the two base panel face sheets may be adjacent to opposite sides of the base panel core material. The stiffener member may be arranged in a defined area of ​​the base panel along the base panel. The stiffener member may include a stiffener member core material and two stiffener member face sheets. Each of the two stiffener member face sheets may be adjacent to opposite sides of the stiffener member core material. The stiffener member may be configured to provide anti-resonance performance to the base panel.

[0010] In some embodiments, attaching the reinforcement member to the base panel may include: composite layup, hot pressing, vacuum forming, vacuum bagging, vacuum assisted resin transfer molding (VARTM), or a combination thereof. In some embodiments, attaching the reinforcement member to the base panel may include: incorporating at least one of screws, adhesives, adhesive films, rivets, or a combination thereof to attach the reinforcement member to the base panel. In some embodiments, the method may further include: before attaching at least one reinforcement member to the base panel, removing an inner portion of the reinforcement member to create a hollow portion in the reinforcement member.

[0011] Embodiments provided herein may also relate to methods of forming a stiffener member. For example, the method may include forming a stiffener member configured to provide anti-resonance performance to a base panel by attaching the stiffener member to a defined area of ​​the base panel. The method may include arranging two stiffener member face sheets over a stiffener member core and then attaching the stiffener member face sheets and stiffener member core to the base panel in a defined area of ​​the base panel.

[0012] In some embodiments, a system may be provided that includes a structure (e.g., a fuselage skin) that defines an outer section and an inner section and may form an enclosed cabin. The structure may be adjacent to an anti-resonance panel and may work in conjunction with the anti-resonance panel to provide improved sound insulation. In some embodiments, the anti-resonance panel may be used in an aircraft that is a system that includes the anti-resonance panel.

[0013] The above brief description is provided only for the purpose of simplifying some exemplary embodiments to provide a basic understanding of some aspects of the present disclosure. Thus, it should be understood that the above embodiments are merely examples and should not be interpreted as narrowing the scope or spirit of the present disclosure in any way. It should be understood that in addition to the embodiments summarized here, the scope of the present disclosure also includes many potential embodiments, some of which will be further described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Having generally described above certain exemplary embodiments of the present disclosure, reference will now be made to the accompanying drawings which are not necessarily drawn to scale:

[0015] Figure 1A and Figure 1B shows an exemplary stiffener member for an anti-resonance panel according to some exemplary embodiments described herein;

[0016] Figures 2A to 2Gshows an exemplary configuration of a stiffener member in an anti-resonance panel according to some exemplary embodiments described herein;

[0017] Figure 3 shows a perimeter-type reinforcement member for reinforcing a sandwich-type reinforcement member according to some exemplary embodiments described herein;

[0018] FIG. 4A to FIG. 4C An exemplary method of abutting a reinforcement member to a base panel according to some exemplary embodiments described herein is shown;

[0019] Figure 5A and Figure 5B An exemplary method of attaching a reinforcement member to a base panel according to some exemplary embodiments described herein is shown;

[0020] FIG. 6A to FIG. 6D shows an exemplary substrate panel forming the basis of an exemplary anti-resonance panel according to some exemplary embodiments described herein;

[0021] Figure 7 shows the addition of an exemplary inertial member to an anti-resonance panel according to some exemplary embodiments described herein;

[0022] Figure 8 shows an exemplary reinforcement member according to some exemplary embodiments described herein;

[0023] Fig.9A and Fig. 9B shows the addition of exemplary reinforcement members to an anti-resonance panel according to some exemplary embodiments described herein;

[0024] Fig. 10A and Fig. 10B shows the addition of an exemplary grounding member to an anti-resonance panel according to some exemplary embodiments described herein;

[0025] Fig.11A and Fig. 11B illustrates a dual pane effect seen in an exemplary anti-resonance panel according to some exemplary embodiments described herein;

[0026] Fig.12 is a flow chart of an exemplary method for providing sound insulation according to some exemplary embodiments described herein;

[0027] Fig.13 is a flow chart of an exemplary method for forming an anti-resonance panel according to some exemplary embodiments described herein;

[0028] Fig.14shows exemplary areas in an aircraft where anti-resonance panels may be used and exemplary anti-resonance treatments for sidewall panels of an aircraft according to some exemplary embodiments described herein;

[0029] Fig.15 shows the insertion loss of an exemplary anti-resonance panel according to some exemplary embodiments described herein;

[0030] Fig.16 shows the addition of an exemplary inertial member to an anti-resonance panel according to some exemplary embodiments described herein; and

[0031] Fig.17 Shown is a dual pane effect seen in an exemplary anti-resonance panel according to some exemplary embodiments described herein. DETAILED DESCRIPTION

[0032] In general, embodiments of the present disclosure provided herein include methods and systems for providing sound insulation, especially for low-frequency noise control. More specifically, sound insulation is provided by using an anti-resonance method. Some embodiments of the present disclosure will now be described more fully below with reference to the accompanying drawings, in which some but not all embodiments of the disclosure are shown. In fact, these disclosures can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; on the contrary, these embodiments are provided so that the present disclosure will satisfy applicable legal requirements. The same reference numerals refer to the same elements throughout.

[0033] As used herein, "anti-resonance performance" refers to the loss of sound transmission due to a reduction in the net vibration displacement of a structure. In the specific embodiments described herein, the reduction in the net vibration displacement of the structure is generally achieved by reflecting the impact sound waves off the component. This reflection can be achieved by the disclosed materials. For example, adding a reinforcement member as described herein to a base panel as described herein can provide anti-resonance performance to the panel, so that the panel becomes an anti-resonance panel.

[0034] The term "mass density" refers to the amount of a substance per unit volume.

[0035] The term "hollow portion" refers to a hole or void of material in a defined area of ​​a corresponding component, such that the hollow portion lacks material that would otherwise be continuous in the component. The hollow portion may be generated by removing an inner portion of a component and may be defined by an inner wall of the component. As used herein, a "defined area" generally refers to an anti-resonance unit or portion of an anti-resonance panel. That is, the anti-resonance panel may be divided into defined areas or portions. A reinforcement member may cover all or part of a defined area. Additional members such as inertial members may be added to the defined area, and reinforcing members and / or grounding members may be added to the defined area, especially along the perimeter forming the defined area.

[0036] As used herein, "acoustic boundary" refers to a limit generally imposed by physical components that creates a defined sound propagation path in which sound is transmitted differently (with respect to speed, path, propagation efficiency, etc.) compared to an adjacent space. As used herein, various components can be incorporated into an anti-resonance panel to create an acoustic boundary to allow for greater control of noise propagation when the panel is contacted. The acoustic boundary can conform to the perimeter of a defined area.

[0037] Overview

[0038] Provided herein are systems, devices, panels and methods for providing noise control, especially by reflecting and / or blocking noise. Sound insulation can be provided, for example, by a sound insulation panel, the sound insulation panel including a reinforcement member that imparts anti-resonance to the panel, the sound insulation panel being then referred to as an anti-resonance panel. The resulting anti-resonance panel can reduce external sound energy passing through the panel, thereby providing improved sound insulation. The anti-resonance panel includes a substrate panel and a reinforcement member distributed along the substrate panel. The anti-resonance panel can achieve an anti-resonance frequency with a local out-of-phase vibration mode to passively neutralize the sound radiation passing through the panel and entering any enclosed structure. In traditional enclosed structures such as aircraft cabins, cars, ships, etc., complex geometries, large sizes and existing attachment components such as windows may impose significant challenges on structural vibration management for noise control. However, the anti-resonance design of the substrate panel combined with the reinforcement member can allow for area noise control for such enclosed structures. The lightweight nature and high bending stiffness of the anti-resonance panel can provide noise control or anti-resonance performance based on anti-resonance. Anti-resonance panels can achieve high sound transmission loss over a wide frequency range, especially in the low frequency region of hundreds to thousands of Hertz (Hz), outperforming traditional methods of adding mass and damping in the same frequency range. Inertial members can be incorporated into anti-resonance panels to further adjust the anti-resonance design thanks to existing components such as attached windows or nearby frames.

[0039] Anti-resonance panels can also improve double-layer sound insulation by interacting with nearby structures such as the fuselage skin of an aircraft. Anti-resonance panels can provide lightweight, compact, practical and economical solutions to provide targeted noise control for structures such as aircraft cabins and other closed structures that are concerned about noise control. Anti-resonance panels can be particularly beneficial to areas where configuration panels are required, because such areas were previously difficult to control acoustically. Anti-resonance panels with different reinforcement components arranged in a defined area along a base panel can be able to follow the desired shape while still achieving the anti-resonance performance of the anti-resonance panel. In some embodiments, anti-resonance panels can provide lightweight sound barriers for structures such as aircraft cabins, and improve existing panels (such as decorative panels for ships, vehicles or aircraft), especially large-sized existing panels with conformal and asymmetric geometries (such as area noise control), and can work with other components of structures such as cabin windows to control noise propagation.

[0040] Anti-resonance panels can replace simple to complex panels. Compared with existing sound insulation panels, anti-resonance panels can have reduced manufacturing costs with simpler manufacturing techniques, can be stiffness controlled, and generally provide panels with reduced mass compared to existing sound insulation panels. Specifically, previous technologies use passive noise control methods such as absorbers, dampers, or sound dampers. These components are usually either too large or too heavy, especially for low-frequency noise control. Active noise control can provide another noise control option. However, active noise control typically requires wiring and power requirements, which makes this option complex, expensive, and difficult to implement for area noise control applications.

[0041] Indeed, there has long been a need for lightweight sound attenuation, especially within enclosed cabins, such as those in automobiles, aircraft, ships, trains, and the like. The state of the art for noise control of vehicle trim panels conventionally involves reusing noise control mechanisms such as Helmholtz-type absorption, constrained layer damping, mass loading, fibrous batting for sound absorption, or combinations thereof. Generally speaking, these methods can be used to cope with noise above 1000 Hz. However, there is a need for lightweight noise control in the low frequency range (e.g., below 1000 Hz).

[0042] Trim panels used in vehicles that require a lightweight design typically include a sandwich design, which enables a relatively durable boundary wall that forms the inner wall of an enclosed cabin, still providing a relatively lightweight solution. Such panels, as well as any panels that are lightweight, relatively rigid, and relatively large in area, are beneficial for sound radiators. These trim panels also constitute a large amount of the interior surface of the vehicle, which makes the trim panels have a major impact on the acoustic characteristics within the vehicle. These trim panels can produce overall vibration modes that dominate the noise frequency range, especially below 1000 Hz, and are difficult to attenuate without mass loading the trim panels, which results in a significant mass penalty and a corresponding reduction in fuel efficiency if mass loading is implemented.

[0043] Passive noise control technology with advantages of light weight, compactness, high noise reduction and environmental robustness is provided here. Anti-resonance panels provide conformal sound insulation panels with high noise reduction, which can provide lightweight noise control solutions for high-quality travel physical examinations. For example, anti-resonance panels can be used as decorative panels, partitions, partition walls, side walls in aircraft cabins and floors for various aircraft models to reduce noise propagation into and between cavities. In addition, anti-resonance panels can be used, for example, as shells or partitions in various commodities, and the commodities include noise components (e.g., motors, pumps, compressors, transmissions, transformers, pipes, etc.) including appliances, grinders, blenders, microwave ovens, shallow pool pumps, etc. Without departing from the intent of the present disclosure, anti-resonance panels can be suitable for various applications, such as any application where noise control is desired.

[0044] Anti-resonance panels can employ a sound reflection mechanism using anti-resonance to reflect acoustic energy from the modulation bandwidth of the panel. The disclosed mechanism can involve a slight increase in mass compared to an unmodified panel, but the mass increase involved can be significantly less than the mass increase that would otherwise be used to generate similar transmission loss performance based on mass law predictions. Anti-resonance panel transmission loss performance can be extended beyond the predicted mass law sound attenuation limit of the panel in the low frequency range of interest by modifying the overall panel vibration modes. In some embodiments, other components such as one or more inertial members, grounding members, and reinforcement members can be added to modify the overall panel vibration modes.

[0045] Anti-resonance panels can be particularly effective in the low frequency range (e.g., about 300 Hz to about 1000 Hz) without adding a significant amount of mass. The anti-resonance bandwidth can be adjusted to meet the target range of problem noise frequencies associated with the unmodified substrate panel as disclosed herein. In addition, because the architectural design and features are expected in most passenger aircraft and vehicles, current engineering decorative panel designs are inherently complex in shape. This complexity can make the implementation of anti-resonance designs difficult. Panels with anti-resonance properties are provided here, which use a variety of panel materials, shapes, sizes and orientations to increase the diversity of panels used in various applications. The noise control mechanism can have the additional benefit of being relatively unaffected by changes in temperature, humidity and pressure, which further makes the panel suitable for vehicles that are conventionally subjected to fluctuations in environmental conditions, such as aircraft, trains and cars.

[0046] Anti-resonance panels can improve existing modulated sandwich sound barriers by implementing anti-resonance control, especially for geometrically complex panels with asymmetric geometry and large size. In addition, anti-resonance panels can improve double-pane sound insulation in terms of wide bandwidth and noise reduction by interacting with nearby panels.

[0047] In some embodiments, pre-conformed materials may be used for anti-resonance panels to create a noise control or sound-damping structure over an area for noise management.

[0048] Having generally described the exemplary embodiments, designs of various configurations for performing various exemplary operations will now be provided.

[0049] Anti-resonance panels having anti-resonance sound-damping properties to provide sound insulation are provided herein. In some embodiments, the technology can be passive in nature, not relying on electronics or actuation for sound-damping properties. The anti-resonance panel can include a sandwich-type base panel that is lightweight and rigid; can be manufactured in a variety of sizes, thicknesses, and materials (such as pre-conformed aerospace materials); and can be installed in a variety of ways. The anti-resonance panel also includes a reinforcement member having a base panel. Without intending to be limited by theory, the reinforcement member provides local stiffness to a specific area ("defined area") of the base panel to result in the anti-resonance performance of the resulting panel.

[0050] Anti-resonance panels can have the ability to block low frequency sounds and can use pre-existing composite materials that may already be fully qualified for use in vehicles such as aircraft. The mechanical properties of anti-resonance panels can provide improved sound blocking properties for sound insulation. Anti-resonance panels can be used in any application where a lightweight, strong panel is desired, such as energy-efficient vehicles, etc.

[0051] Figure 1AExemplary shapes for the reinforcement member 108 are shown. Figure 1B Additional exemplary shapes for the reinforcement member 108 are shown. The reinforcement member 108 may include, for example, Figure 1B The hollow portion 124 shown in the figure changes the stiffness and surface density of the final design of the reinforcement member 108 to ultimately change the stiffness-to-weight ratio of the reinforcement member 108. The reinforcement member 108 may include an inner wall 122 defining the hollow portion 124 in the reinforcement member 108. The hollow portion 124 may be cut vertically through the reinforcement member 108 (e.g., through each reinforcement member core material 114 and reinforcement member face sheets 116, 117 ( Figures 2A to 2G )). This hollowing out of the stiffener member 108 can reduce the mass of the stiffener member 108 without significantly reducing the stiffness of the stiffener member 108. That is, the stiffener member 108 remains stiff enough to manipulate the dynamics of the anti-resonance panel 100 without significantly increasing the mass of the anti-resonance panel 100. Variations in this manipulation of the stiffener member 108 can be used to obtain desired anti-resonance performance.

[0052] Figures 2A to 2G Various exemplary configurations of stiffener members 108 on the base panel 102 are provided. To provide an anti-resonance effect, one or more stiffener members 108 may be used in conjunction with the base panel 102. The stiffener members 108 control the overall vibration modes and achieve an anti-resonance design. The stiffener members 108 may include any shape, number, orientation, or position as desired to achieve the anti-resonance performance of the resulting anti-resonance panel 100. For example, in some embodiments, the stiffener members 108 may be about 10% to about 30% of the total mass of the anti-resonance panel 100, such as about 15% to about 25% of the total mass of the anti-resonance panel 100, such as about 20% or less of the total mass of the anti-resonance panel 100.

[0053] The reinforcement members 108 may cover less than 40% of the total surface area of ​​the anti-resonance panel 100 (e.g., less than 40% of the total surface area of ​​the side of the anti-resonance panel 100 on which the reinforcement members 108 are placed), such as less than 35% of the total surface area of ​​the anti-resonance panel 100 (e.g., less than 35% of the total surface area of ​​the side of the anti-resonance panel 100 on which the reinforcement members 108 are placed), such as less than 30% of the total surface area of ​​the anti-resonance panel 100 (e.g., less than 30% of the total surface area of ​​the side of the anti-resonance panel 100 on which the reinforcement members 108 are placed), such as less than 25% of the total surface area of ​​the anti-resonance panel 100 (e.g., less than 25% of the total surface area of ​​the side of the anti-resonance panel 100 on which the reinforcement members 108 are placed), such as less than 20% of the total surface area of ​​the anti-resonance panel 100 (e.g., less than 20% of the total surface area of ​​the side of the anti-resonance panel 100 on which the reinforcement members 108 are placed). In some embodiments, the stiffener members 108 may be arranged along less than 25% of the total surface area of ​​the base panel 102, and the mass of the stiffener members 108 may be about 20% of the total mass of the anti-resonance panel 100. With such low coverage of the total surface area of ​​the base panel 102 (e.g., less than 40% of the total surface area of ​​the anti-resonance panel 100) and low mass addition to the total mass of the anti-resonance panel 100 (e.g., less than 30% of the total mass of the anti-resonance panel 100), the stiffener members 108 can increase the stiffness of the base panel 102 without significantly affecting the mass of the base panel 102, and can provide control of the anti-resonance performance due to the discreteness of the stiffener members 108. The density and thickness of the stiffener members 108 can be varied based on the desired anti-resonance performance. The stiffener members 108 generally have a low mass density and high stiffness.

[0054] Figures 2A to 2G The various configurations presented in are just a few example configurations that can vary the stiffness and mass density characteristics of the resulting anti-resonance panel 100. The stiffener members 108 of the present disclosure are not limited to Figures 2A to 2G , and may include various materials in various configurations without departing from the intent and scope of the present disclosure. For example, the reinforcement member 108 may be a combination of the following materials and / or other materials and designs that provide the desired lightweight but rigid combination and impart an acoustic boundary 132 to the base panel 102. For example, the reinforcement member face sheets 116, 117 may be a lightweight strong material such as carbon fiber, glass fiber, or a combination thereof. The reinforcement member core 114 may include a foam (e.g., polyethylene terephthalate (PET) foam), have a honeycomb structure (e.g., an aramid honeycomb structure), additionally have a porous structure, or a combination thereof. In some embodiments, the reinforcement member core 114 may include PET foam, an aramid honeycomb structure, or a combination thereof.

[0055] The reinforcement member face sheets 116, 117 may include carbon fiber, glass fiber, combinations thereof, or other similar materials. In some embodiments, the reinforcement member face sheets 116, 117 may include carbon fiber, glass fiber, fiber composites, or combinations thereof. Metal (e.g., aluminum) struts, trusses, or porous structures may be used to impart stiffness without significantly increasing mass. Figures 2A to 2G 108, two different strength member core materials 114 are shown. Because the strength member 108 is a discrete, concentrated area along the base panel 102, the material can have a higher modulus than the material typically used to construct the base panel 102. In addition, materials that may have large areas of flammability concerns can be used in the strength member 108, because the strength member 108 is generally a smaller, more concentrated discrete area along the base panel 102, rather than along the entire length / width of the base panel 102.

[0056] like Figures 2A to 2G As shown, the reinforcement member 108 may be formed using a plurality of reinforcement member face sheets 116 and / or 117, and / or a plurality of reinforcement member cores 114 may be used to form the reinforcement member 108. In some embodiments, a plurality of reinforcement members 108 may be arranged on the base panel 102. For example, Figure 2E The anti-resonance panel 100 includes a first reinforcement member 108a and a second reinforcement member 108b respectively located in corresponding defined areas 110a, 110b on the base panel 102. The first reinforcement member 108a and the second reinforcement member 108b are Figure 2E 108a and 108b may be of the same composition, but the composition of the first and second stiffener members 108a, 108b may be the same or different, and more than two stiffener members 108 may be incorporated on / in the base panel 102. Variations in the number and combination of these materials may be used to achieve the desired anti-resonance performance.

[0057] In some embodiments, the anti-resonance panel 100 may include a stiffener member 108 disposed on one of the two base panel deck sheets 106, 107. In some embodiments, the anti-resonance panel 100 may include a stiffener member 108 disposed between the two base panel deck sheets 106, 107 and adjacent to the base panel core 104. FIG. 2A to FIG. 2E A reinforcement member 108 is shown applied to the base panel face sheets 106, 107, and Figure 2F and Figure 2G A reinforcement member 108 is shown applied to the interior of the base panel 102 and covered by the base panel face sheets 106, 107. Figure 2Fand Figure 2G In the embodiment shown in FIG. 1 , the reinforcement member 108 replaces a portion of the base panel core material 104. Figure 2G As shown, the first stiffener member face sheet 116 may be applied to the exterior of the base panel face sheet 106 using an adhesive (attachment mechanism 146). This placement of the stiffener member face sheet 116 may further increase the bending stiffness of the defined area 110 where the stiffener member 108 is disposed.

[0058] When applied to the interior of the base panel 102, the stiffener member 108 may include a stiffener member core 114 and one or more stiffener member face sheets 116, 117, or may include only a stiffener member core 114 without one or more stiffener member face sheets 116, 117. The stiffener member face sheets 116, 117 may be applied to the interior of the base panel 102 (e.g., between one or more base panel face sheets 106, 107 ( Fig. 6A 6D ) and / or applied to the exterior of the base panel 102 (e.g., located above one or more base panel face sheets 106, 107).

[0059] The stiffener members 108 can be designed to provide a desired degree of anti-resonance performance by including the stiffener members 108 in specific areas of the base panel 102 (e.g., defined areas 110) and by means of specific configurations. That is, the materials, size, shape, and material composition used for the stiffener members 108 can be modified to achieve the desired anti-resonance behavior. In some embodiments, the anti-resonance panel 100 can include two or more stiffener members 108 (e.g., Figure 2E ), each reinforcement member is positioned along the base panel 102 at a corresponding defined area 110 of the base panel 102 (e.g., as shown in FIG. Figure 2E In the first defined area 110a and the second defined area 110b shown in FIG.

[0060] Without intending to be limited by theory, the stiffener member 108 can provide an effective acoustic boundary on the base panel 102, thereby enabling the overall resonant mode of the anti-resonance panel 100 to be changed (i.e., the vibration modes of the entire base panel 102, such as the first and second main modes and the anti-resonance mode between the two). In some embodiments, the stiffener member 108 can have a sandwich construction (e.g., including two stiffener member face sheets 116, 117 surrounding the stiffener member core 114 on opposite sides of the stiffener member core 114), which can achieve a lightweight but high bending stiffness resulting in a sandwich stiffener member 108. Various other stiffener member 108 constructions with high stiffness-to-mass ratios are discussed herein. The high stiffness-to-mass ratio can allow for anti-resonance performance and, at the same time, high fuel efficiency when applied to a vehicle. In some embodiments, the anti-resonance panel 100 can be configured to reduce noise propagating through the anti-resonance panel 100 at frequencies between about 300 Hz and about 1000 Hz. For example, the anti-resonance panel 100 may include a substrate panel 102 (eg, Figures 2A to 2G , FIG. 4A to FIG. 4C , Figure 5A to Figure 5B and FIG. 6A to FIG. 6D The reinforcement member 108 (e.g. Figure 1A to Figure 1B , Figures 2A to 2G , FIG. 4A to FIG. 4C and FIG. 5A to FIG. 5B The reinforcement member 108 in the anti-resonance panel 100 can reduce the propagation of noise through the anti-resonance panel 100 at low frequencies (eg, about 300 Hz to about 1000 Hz), which is generally difficult to reduce or control with only the base panel.

[0061] In some embodiments, one or more stiffener members 108 may be added to one or more base panels 102 , and specifically to one or more base panel face sheets 106 , 107 , to alter the stiffness-to-mass ratio of the base panel 102 . The anti-resonance panel 100 includes a base panel 102 including a base panel core 104 and two base panel face sheets 106, 107, each of which is adjacent to opposite sides of the base panel core 104; and at least one stiffener member 108 positioned along the base panel 102 in a defined area 110 of the base panel 102, the defined area 110 being less than the entire area 112 of the base panel 102; wherein the stiffener member 108 includes a stiffener member core 114 and two stiffener member face sheets 116, 117, each of which is adjacent to opposite sides of the stiffener member core 114, and wherein the stiffener member 108 is configured to provide anti-resonance performance to the base panel 102. The stiffener member 108 may be configured to provide anti-resonance performance to the base panel 102 by adding stiffness to the defined area 110 of the base panel 102 at a low mass density.

[0062] For example, if 2A to Figure 2G , Figure 3 , FIG. 4A to FIG. 4C As shown, the reinforcement member 108 can provide stiffness by being constructed as a sandwich reinforcement member including a reinforcement member core material 114 and at least one reinforcement member face sheet 116, 117 and made from the materials described herein. In some embodiments, the reinforcement member 108 can be provided by Figure 1B As shown, the hollow portion 124 and / or FIG. 5A to FIG. 5B or Figure 4A4C is arranged on the base panel to increase stiffness at a low mass density. The one or more reinforcement members 108 are arranged on the outer surface of the one or more base panel face sheets 106, 107. In some embodiments, the one or more reinforcement members 108 can be added to the inner base panel core material 104 and then surrounded by the base panel face sheets 106, 107. The one or more reinforcement members 108 are applied to the base panel core material 104 and / or used in place of the base panel core material 104 in a defined area 110 of the base panel 102. One or more reinforcement members 108 can be added to a defined area 110 of the base panel 102 to change the stiffness-to-mass ratio of the base panel 102 at a specific point along the base panel 102. Various stiffener member face sheets 116 , 117 , adhesive films or materials (collectively “attachment mechanisms” 146 ), and stiffener member cores 114 may be used to form the stiffener member 108 and achieve the desired stiffness and specific mass properties of the final stiffener member 108 and resulting anti-resonance panel 100 .

[0063] Figure 1A to Figure 1B as well as Figures 2A to 2G The configurations described in are examples of implementations that can be effectively used as stiffener members 108 for anti-resonance performance. Combinations of these embodiments and other configurations of stiffener members 108 can be used in conjunction with the base panel 102 to provide an anti-resonance panel 100 with improved anti-resonance performance.

[0064] In some embodiments, Figure 3 As shown, the reinforcement member 108 may include a peripheral reinforcement member 118 that is lightweight and further increases the stiffness of the anti-resonance panel 100. The anti-resonance panel 100 may include a peripheral reinforcement member 118 disposed along one or more edges 120 of the reinforcement member 108. For example, in some embodiments, the peripheral reinforcement member 118 may be included to reinforce the reinforcement member 108, such as a sandwich reinforcement member 108 (see, for example, Figure 3 ), or can be used alone as a stiffener member 108. The peripheral stiffener member 118 is particularly effective when arranged along the perimeter of the sandwich stiffener member 108 to further improve the anti-resonance performance of the anti-resonance panel 100. For example, Figure 3 A lightweight perimeter-type reinforcement member 118 is shown reinforcing the sandwich-style reinforcement member 108 , which is then joined to the sandwich-style base panel 102 .

[0065] like Figure 3As shown, the perimeter reinforcement member 118 may have a Z-shaped cross-section (e.g., a vertical portion connects two parallel horizontal portions, and the two parallel horizontal portions are independently connected to the vertical portions at opposite ends of the horizontal portions to form a Z-shaped cross-section) and extend along one or more sides or edges 120 of the sandwich reinforcement member 108. For example, in Figure 3 In the illustrated embodiment, the perimeter reinforcement member 118 follows the perimeter of the sandwich reinforcement member 108 along three edges 120 of the sandwich reinforcement member 108. However, the perimeter reinforcement member 118 may follow one, two, or all edges 120 of the sandwich reinforcement member 108. Figure 3 The three or more edges 120 of the perimeter shown, when connected, particularly increase the stiffness of the anti-resonance panel 100. The perimeter type stiffener member 118 may have an I-shaped cross-section (e.g., a vertical portion connecting two parallel horizontal portions centered at the top and bottom of the vertical portions to form an I-shaped cross-section), an L-shaped cross-section (e.g., a single horizontal portion attached to the bottom of a single vertical portion to form an L-shaped cross-section), a Z-shaped cross-section, a T-shaped cross-section (e.g., a single horizontal portion attached to the top of a single vertical portion to form a T-shaped cross-section), or may have any other suitable configuration to provide a lightweight stiffener member 108 to the sandwich base panel 102.

[0066] In some embodiments, the material used for the stiffener member 108 may be a pre-conditioned material that has been adapted for the aerospace or automotive industries. In some embodiments, the same material that makes up the base panel 102 may be used for the stiffener member 108, although the two may differ in configuration, size, and thickness to achieve the desired anti-resonance performance.

[0067] The anti-resonance performance of the anti-resonance panel 100 may be further improved by maximizing the bonding stiffness of the stiffener members 108 to the base panel 102. The bonding of the stiffener members 108 to the base panel 102 may be made as complete as possible, particularly along the perimeter or edge 120 of the stiffener members 108. FIG. 4A to FIG. 4C An exemplary method of adjoining the stiffener member 108 to the base panel 102 is provided. Figure 4A A high stiffness, highly conformal stiffener member 108 is provided that is formed in a mold to match the shape of a base panel 102. As used herein, "conformal" refers to something that is shaped to closely match adjacent components. For example, with respect to a conformal stiffener member 108, a surface of the stiffener member 108 (e.g., one of the stiffener member face sheets 116, 117) is in close proximity to the base panel 102 and follows the curvature of the base panel 102. The stiffener member 108 geometry is traced and cut away to form the stiffener member 108 for the anti-resonance panel 100.

[0068] Particularly useful for complex stiffener members 108, the stiffener members 108 can be prefabricated in a mold as stiffener member panel stock 150. Specific areas (stiffener member cutouts 152) predetermined to produce the desired anti-resonance performance are cut out of the stiffener member panel stock 150 and superimposed onto the existing base panel 102 as stiffener members 108. If a specific defined area 110 of a stiffener member 108 is required to be complex or highly configured, such as Figure 4A This process allows for a highly adhesive bonding of the stiffener members 108 to the base panel 102 , which can increase the effective stiffness of the resulting anti-resonance panel 100 .

[0069] The stiffener members 108 may be coupled to the base panel 102 by other methods. Figure 4B An exemplary process for forming a stiffener member 108 on a substrate panel 102 is shown. Specifically, Figure 4B An exemplary method of forming a stiffener member 108 through a layup process is shown, wherein the components that make up the stiffener member 108 (in this embodiment, the stiffener member face sheets 116, 117, the attachment mechanism 146, and the stiffener member core 114) are flat but flexible to allow the components to take on the surface contours of the base panel 102 (including the base panel face sheets 106, 107 and the base panel core 104) during the layup process. The stiffener member 108 and the base panel 102 are then bonded together to form the anti-resonance panel 100. Once the arrangement has been established, an autoclave may be used to achieve higher bonding pressures, or sandbags may be applied over the attachment to aid bonding. Figure 4B The method shown in can be more cost-effective and efficient than other methods.

[0070] Figure 4C Another exemplary method of attaching the reinforcement member 108 to the base panel 102 is shown. Figure 4C In the illustrated embodiment, the reinforcement member 108 may be cut from reinforcement member panel stock 150 (see, for example, Figure 4A ), by means of pre-cut components of the reinforcement component, the reinforcement component is assembled (see, for example, Figure 4B), etc. or a combination thereof. The reinforcement member 108 includes a reinforcement member core 114 and reinforcement member face sheets 116, 117. A portion of the base panel core 104 may be removed to allow for the insertion of the reinforcement member 108. The base panel face sheets 106, 107 may then be applied to the base panel core 104 and the reinforcement member 108 to form the anti-resonance panel 100. In this embodiment, the reinforcement member 108 is incorporated into the base panel 102, thereby imparting the stiffness characteristics of the reinforcement member 108 to the base panel 102 and providing the resulting anti-resonance panel 100 with a flush or regular surface. In some embodiments, the reinforcement member 108 may be incorporated into the base panel 102 by adhering the reinforcement member 108 to the base panel core 104 and then applying the base panel face sheets 106, 107 over both the reinforcement member 108 and the base panel core 104 without cutting out a portion of the base panel core 104. Variations of these methods may be used without departing from the intent of the present disclosure, and other methods may be used to achieve similar results based on available supplies or resources.

[0071] Once a design for the reinforcement member 108 is specified, it can be Figure 5A and Figure 5B Some of the embodiments shown attach the reinforcement member 108 to the base panel 102 by a number of means. Specifically, Figure 5A and Figure 5B An exemplary process for attaching the reinforcement member 108 to the base panel 102 is provided. Figure 5A In FIG. 5A , the reinforcement member 108 is prefabricated and attached to the base panel 102 by means of mechanical fasteners (e.g., attachment mechanism 146). FIG. 5A also shows a cross-section of the resulting anti-resonance panel 100. Figure 5B In the embodiment of the present invention, the reinforcement member 108 is prefabricated and attached to the base panel 102 by means of an adhesive film (eg, attachment mechanism 146) and an autoclave layup. Figure 5B A cross section of the resulting anti-resonance panel 100 is also shown, showing the stiffener member 108 attached directly to the base panel 102. Variations of bonding techniques may be used, such as heat pressing, vacuum bagging, sandbagging, and the like, and combinations thereof, and various materials may be used, such as screws, adhesives, adhesive films, rivets, and combinations thereof. For example, in one embodiment, a rigid foam-forming adhesive may be used to ensure that the gap between two interfaces (e.g., between the stiffener member 108 (e.g., one or more stiffener member face sheets) and the base panel 102) is securely filled and attached. Various methods of attaching components may be used without departing from the intent and scope of the present disclosure. For example, in some embodiments, it may be desirable to combine FIG. 4A to FIG. 4C as well as FIG. 5A to FIG. 5B One or more manufacturing and attachment techniques.

[0072] FIG. 6A to FIG. 6D Detailed Description of the Invention An exemplary substrate panel 102, and specifically a sandwich substrate panel 102, is shown that may be used in an anti-resonance panel 100 as described herein. FIG. 6A to FIG. 6D Each base panel 102 shown in the figure includes base panel face sheets 106, 107 and base panel core material 104 constituting a panel sandwich base panel 102. FIG. 6A to FIG. 6D The embodiment shown in the figure uses the same base panel face sheets 106, 107 on either side of the base panel core material 104, but the base panel face sheets 106, 107 can be varied within the anti-resonance panel 100 (i.e., different types (e.g., materials) of base panel face sheets 106, 107 can be used on opposite sides of the base panel core material 104 and / or along the same side of the base panel core material 104). In addition, although FIG. 6A to FIG. 6D The embodiment shown in FIG. 1 uses the same base panel core 104 for both the length and width of the base panel 102 , but the base panel core 104 may vary within the anti-resonance panel 100 .

[0073] Fig. 6A The flat sandwich type base panel 102 has carbon fiber base panel face sheets 106 , 107 surrounding an aramid honeycomb base panel core 104 . Figure 6B It is a thicker base panel core material 104 and a configuration shape (base panel panel sheets 106, 107 and base panel core material 104) and is used with Fig. 6A A sandwich base panel 102 is constructed of the same material. Figure 6C is a flat sandwich composite base panel 102 having fiberglass base panel face sheets 106, 107 surrounding an aramid honeycomb base panel core 104 having in-plane profiled cutouts. Fig.6D The base panel 102 is a sandwich type base panel consisting of thin aluminum base panel face sheets 106 , 107 surrounding a PET foam base panel core 104 . Fig.6D The thickness of the base panel 102, and in particular the base panel core 104, varies along the base panel 102 to create a profiled portion 160 of the base panel 102. The profiled base panel 102 may include various curvatures and angles to provide a desired shape and configuration. For example, the base panel 102 may be profiled in different portions of the base panel 102 to specifically match a desired location in a wall in which the anti-resonance panel 100 is to be used and / or to achieve a desired soundproofing performance of the anti-resonance panel 100.

[0074] The substrate panel 102 of the present disclosure is not limited to FIG. 6A to FIG. 6DThe substrate panels shown in , and may include various materials in various configurations without departing from the intent and scope of the present disclosure. For example, the substrate panel 102 in the anti-resonance panel 100 may be a combination of these materials and / or other materials and designs that produce a lightweight and rigid panel with anti-resonance properties.

[0075] As the panel size increases, the anti-resonance sound damping performance becomes weaker for the low frequency range of the acoustic frequency, such as 300 Hz to 1000 Hz, along with the larger effective acoustic boundary. This behavior is usually governed by the generation of undesirable acoustic vibration modes at different frequencies with characteristic geometric patterns superimposed on the panel. Mitigation of these modes can be addressed by modifying specific locations on the panel determined by various tools used in acoustic measurement and modeling through the use of reinforcement members 108. Additional components can be added to the anti-resonance panel 100 to provide improved performance. For example, inertial members 126 (see, e.g., Figure 7 ), reinforcing member 128 (see e.g. Figure 8 ), grounding member 134 (see e.g. Fig.9A and Fig. 9B ) and combinations thereof to further improve the anti-resonance properties of the anti-resonance panel 100. These treatments can further adjust the anti-resonance performance of the anti-resonance panel 100. In some embodiments, the additional components can provide a wider transmission loss bandwidth, can change the bandwidth to a higher frequency, or a combination thereof. As an additional benefit, the inertial members 126 and / or grounding members 134 along the defined acoustic boundaries 132 that subdivide the anti-resonance panel 100 effectively increase the quality factor (Q) of the anti-resonance performance, which even further increases the sound blocking performance.

[0076] The inertial members 126 are typically discrete, high-density components added to the anti-resonance panel 100 to provide a relatively small amount of mass in a specific portion of the anti-resonance panel 100. The anti-resonance panel 100 may include at least one inertial member 126. The inertial member 126 is configured to provide an increase in mass over a defined area 110 of the anti-resonance panel 100. For example, Figure 7As shown, one or more inertial members 126 may be added to the anti-resonance panel 100. In such cases, the inertial members 126 include materials and have a geometry to increase the mass density of the anti-resonance panel 100 at specific locations of the inertial members 126. That is, the inertial members 126 provide a high mass density in a small diameter (e.g., the inertial members 126 generally have a smaller diameter than the diameter of the stiffener members 108, but have a higher mass density than the mass density of the stiffener members 108). In some embodiments, the inertial members 126 may have a mass density that is about 5 times, 10 times, or more times the mass density of the stiffener members 108, and are generally too small to provide stiffness to the anti-resonance panel 100 (e.g., the inertial members 126 have a smaller diameter than the diameter of the stiffener members 108, but do not provide the stiffness that the stiffener members 108 can provide). The inertial members 126 may have a mass density that is about 10 times the mass density of the stiffener members 108. The mass density may be such that a high mass increase is provided above the small diameter to effectively increase the mass at that location without significantly increasing the overall mass of the anti-resonance panel 100. In contrast, the stiffener members 108 may increase the stiffness of the panel without significantly increasing the mass of the panel.

[0077] For example, the density of the inertial member 126 may be approximately 0.5 kg / m 3 About 30kg / m 3 , such as about 1 kg / m 3 About 20kg / m 3 The inertial member 126 provides a concentrated mass at a specific location, which moves the local mode out of the target frequency range or suppresses the local vibration (e.g. Fig.15 ). In some embodiments, with the inertial member 126 incorporated, there are diminishing returns in the transmission loss gained with increasing mass. Thus, adding the inertial member 126 is a balance between increased mass and desired transmission loss in a desired frequency range. Adding the inertial member 126 as a point mass can help maintain anti-resonance with minimal mass increase. The inertial member 126 can include solid aluminum, rubber, tungsten, ceramic, or a combination thereof, as these materials provide relatively high mass density without significantly increasing the mass of the panel.

[0078] The inertial member 126 provided herein may be any suitable geometry and material that provides a relatively small amount of mass to help adjust the acoustic characteristics of the anti-resonance panel 100. The inertial member 126 may be secured using an attachment mechanism (e.g., attachment mechanism 146), such as mechanical fasteners, adhesives, other methods mentioned herein, etc., or a combination thereof. Although the inertial member 126 may be implemented in any shape, the inertial member 126 is limited to being able to effectively act as a point mass regardless of shape.

[0079] Figure 7 An exemplary inertial member 126 is shown coupled to the anti-resonance panel 100 . Figure 7 Both the inertial member 126 and the stiffener member 108 (one stiffener member face sheet 116 and stiffener member core 114 are shown) are shown sandwiched on a base panel 102 (including base panel face sheets 106 , 107 and base panel core 104 ) to form the anti-resonance panel 100 .

[0080] Another approach to preserve the anti-resonance performance is to use reinforcement members 128 to reinforce the area of ​​the anti-resonance panel 100 (see Fig.9A and Fig. 9B ). The anti-resonance panel 100 may include reinforcement members 128. The reinforcement members 128 are arranged along a perimeter 130 of a defined area 110 of the base panel 102 and define an acoustic boundary 132 for the defined area 110 of the base panel 102. The reinforcement members 128 acoustically divide the anti-resonance panel 100 by applying a barrier at specific locations along the anti-resonance panel 100 to form the acoustic boundary 132. The reinforcement members 128 can help improve the control of the overall acoustic performance of the anti-resonance panel 100 through this division. The reinforcement members 128 can be placed in any orientation, and any number of reinforcement members 128 can be used in locations suitable for improving anti-resonance performance. The reinforcement members 128 can help define the acoustic boundary 132 of the anti-resonance panel 100, especially the non-planar or configured anti-resonance panel 100.

[0081] Figure 8 The cross-sectional profiles of exemplary reinforcement members 128 that may be used to reinforce various anti-resonance panels 100 are shown. Both solid structural and sandwich reinforcement members 128 are shown. The cross-sectional geometries of the reinforcement members 128 may include several types commonly used in the industry (I-shaped, L-shaped, Z-shaped, T-shaped, etc.) as well as newer or more complex cross-sectional geometries that maximize the stiffness to mass ratio. The length and size of the reinforcement members 128 may be designed to achieve specific anti-resonance performance.

[0082] The reinforcement member 128 may be made of any type of material, may be a composite material, have a sandwich type construction, etc., or a combination thereof, suitable for providing a lightweight component with high bending stiffness (e.g., comparable to the stiffener member 108). The attachment mechanism 146 for the reinforcement member 128 may be the attachment mechanism previously described for attaching the stiffener member 108, or other mechanisms that advantageously limit vibration motion with minimal increase in mass density over the footprint of the reinforcement member 128. The reinforcement member 128 may include a variety of materials, such as pre-approved composite materials, such as those found in the base panel 102 construction. The reinforcement member 128 may be constructed in a perimeter construction similar to the perimeter type stiffener member 118, as long as the reinforcement member 128 enhances the separation of the anti-resonance panel 100 to create an acoustic boundary 132 for a more efficient anti-resonance panel 100. The reinforcement member 128 is typically an elongated member (length greater than width).

[0083] Fig.9A An exemplary reinforcing member 128 is shown that can further improve the anti-resonance control of the anti-resonance panel 100 and facilitate transmission loss. More specifically, Fig.9A 9B shows a system 200 including a reinforcing member 128 for horizontally reinforcing an anti-resonance panel 100 for use as an aircraft cabin panel 202. FIG9B shows a system 200 including a vertical sandwich reinforcing member 128 reinforcing a portion of an anti-resonance panel 100 for use as an aircraft cabin panel 202. Various configurations of reinforcing members 128 may be used to improve the anti-resonance performance of the anti-resonance panel.

[0084] The anti-resonance panels 100 are periodically mounted to, for example, the fuselage skin 137 (see, e.g., Fig.14 ) or window 224 (see, for example Fig.9A and Fig. 9B ) structure 136, which can be used to further redefine the acoustic boundary 132, which is beneficial for anti-resonance performance (see, for example Fig. 10A and Fig. 10B ).

[0085] Reference Fig. 10A and Fig. 10B, the grounding member 134 may be used to anchor the anti-resonance panel 100 to other components of the structure 136, such as the fuselage skin 137 or the window 224. The anti-resonance panel 100 may include the grounding member 134. The grounding member 134 is configured to anchor the anti-resonance panel 100 to the structure 136, such as the fuselage skin 137 or the window 224, and define an acoustic boundary 132 for the defined area 110 of the base panel 102. The grounding member 134 may utilize an existing portion of the structure 136 (e.g., a portion with high mass, such as the fuselage skin 137 or the window 224) to provide a more stable vibro-acoustic boundary 132 for the anti-resonance panel 100. The grounding member 134 may help to isolate and control vibrations and improve the anti-resonance performance of the anti-resonance panel 100.

[0086] When the anti-resonance panel 100 is used in an aircraft (e.g., Fig.13 In embodiments of aircraft 145 in FIG. 1 , several locations along the fuselage skin 137 may be used as anchor points to attach the grounding member 134 to the anti-resonance panel 100 to further improve anti-resonance performance. Convenient anchoring locations on portions of the fuselage skin 137, such as windows 224, stringers, perimeter frame portions, or similar nearby points may be used. The anchor points selected for attaching the grounding member 134 to the anti-resonance panel 100 may also include nearby components that are anchored to the fuselage skin 137 to reduce the additional mass of fasteners or components required to achieve effective anchoring performance.

[0087] Fig. 10A A side view of an exemplary system 200 including the anti-resonance panel 100 and adjacent fuselage skin 137 is shown, and Fig. 10B A rear view of an exemplary system 200 including an anti-resonance panel 100 and an adjacent fuselage skin 137 is shown. An exemplary grounding member 134 is shown. The grounding member 134 is attached at a specific portion of the anti-resonance panel 100 to form a suitable acoustic boundary 132 that facilitates anti-resonance performance. The grounding member 134 may include a bracket, anchor bolts, other fasteners, or a combination thereof that has the ability to anchor the portion of the anti-resonance panel 100 to which the grounding member 134 is attached and the adjacent fuselage skin 137. In addition, damping may be added along the anchored grounding member 134 to reduce induced vibrations from the fuselage skin 137 to the anti-resonance panel 100 at the attachment point or area.

[0088] In aircraft (see for example Fig.14In an aircraft 145 in FIG. 1 , while an aircraft trim panel 154 defines the side walls of the cabin of the vehicle, the fuselage skin 137 located behind the trim panel 154 serves as the outer vehicle body. The gap between these two components (the trim panel 154 and the fuselage skin 137) can be acoustically exploited, where the overall sound attenuation can be increased over a wide bandwidth. This architecture can be referred to as a double-pane structure. The trim panel 154 can be replaced with one or more anti-resonance panels 100 having a base panel 102 and one or more reinforcement members 108. Thus, the anti-resonance panel 100 serves as an inner sidewall panel that at least partially defines an enclosed cabin 155 of the aircraft 145.

[0089] Double-pane acoustics usually have two low-frequency resonant modes, such as Fig.11A and Fig. 11B As shown, the sound attenuation increases rapidly as the frequency increases. If properly accounted for, the anti-resonance properties of the anti-resonance panel 100 and the double pane effect can work together to extend the overall sound transmission loss through the anti-resonance panel 100 into the enclosed structure (e.g. Fig.14 in a closed cabin 155). Fig.11A and Fig. 11B shows that the in-phase resonance ( Fig.11A ) and out-of-phase resonance with each other ( Fig. 11B ) caused by two structures (e.g., the fuselage skin 137 and the anti-resonance panel 100).

[0090] Reference Fig.12In some embodiments, a method 1100 for manufacturing an anti-resonance panel 100 having a base panel 102 is provided, the base panel 102 having a base panel core 104 and two base panel face sheets 106, 107. Each of the two base panel face sheets 106, 107 is adjacent to opposite sides of the base panel core 104, respectively. The method 1100 includes attaching at least one stiffener member 108 to the base panel 102 (step 1110). As described above, the stiffener member 108 is arranged along the base panel 102 in a defined area 110 of the base panel 102, and the base panel 102 includes the base panel core 104 and the two base panel face sheets 106, 107. The stiffener member 108 includes a stiffener member core 114 and two stiffener member face sheets 116, 117. The stiffener member 108 is configured to provide anti-resonance performance to the base panel 102. In some embodiments, attaching the reinforcement member 108 to the base panel 102 may include composite layup, heat pressing, vacuum forming, vacuum bagging, vacuum assisted resin transfer molding (VARTM), or a combination thereof (step 1112). In some embodiments, attaching the reinforcement member 108 to the base panel 102 may include incorporating at least one attachment mechanism 146 for attaching the reinforcement member 108 to the base panel 102, including screws, adhesives, adhesive films, rivets, or a combination thereof (step 1114).

[0091] Fig.12 An exemplary method 1100 for providing sound insulation to a structure (eg, a fuselage skin 137) according to some embodiments described herein is shown. Specifically, the method 1100 includes attaching at least one stiffener member 108 to the base panel 102 (step 1110) (eg, see Figures 2A to 2G , FIG. 4A to FIG. 4C , Figure 5A and Figure 5B and the descriptions associated with each provided herein). The method 1100 may also include providing a base panel 102 including a base panel core 104 and two base panel face sheets 106, 107 (step 1108) (see, for example, FIG. 6A to FIG. 6D ). As described above, attaching the reinforcement member 108 to the base panel 102 may include composite layup, heat pressing, vacuum forming, vacuum bagging, VARTM, and combinations thereof (step 1112). Attaching the reinforcement member 108 to the base panel 102 may include incorporating at least one attachment mechanism 146 for attaching the reinforcement member 108 to the base panel 102, including screws, adhesives, adhesive films, rivets, or combinations thereof, as shown in step 1114. Various embodiments described herein may be incorporated into a method of providing sound insulation.

[0092] In some embodiments, the method 1100 may include removing an inner portion 148 of the reinforcement member 108 to create a hollow portion 124 in the reinforcement member 108 prior to attaching the at least one reinforcement member 108 to the base panel 102 (step 1109 ).

[0093] Fig.13 1 is a flow chart of an exemplary method 1200 for forming an anti-resonance panel 100 according to some exemplary embodiments described herein. Specifically, the method 1200 includes: forming a stiffener member 108 configured to provide anti-resonance performance to a base panel 102 by arranging at least one stiffener member face sheet 116 and / or 117 on a stiffener member core 114 (step 1210); and attaching the stiffener member 108 to a defined area 110 of the base panel 102 (step 1220). Various embodiments disclosed herein can be incorporated into a method of providing sound insulation.

[0094] Reference Fig.9A and Fig. 9B , Fig. 10A and Fig. 10B as well as Fig.11A and Fig. 11B In some embodiments, the system 200 may be configured to include a structure 136 (e.g., a fuselage skin 137) and at least one anti-resonance panel 100 adjacent to the structure (e.g., a fuselage skin 137). The structure 136 (e.g., a fuselage skin 137) defines an inner section 138a and an outer section 138b and may form an enclosed cabin 155. The structure 136 (e.g., a fuselage skin 137) is adjacent to the anti-resonance panel 100 and may function in conjunction with the anti-resonance panel 100 to provide improved sound insulation (e.g., see the description of the embodiment of the present invention). Fig. 10A and Fig. 10B The grounding member 134 and / or the Fig.11A and Fig. 11B In some embodiments, the anti-resonance panel 100 is used in an aircraft (eg, the aircraft 145 ), where the aircraft is a system 200 having the anti-resonance panel 100 .

[0095] Fig.14 Exemplary areas where the anti-resonance panel 100 may be used on an aircraft 145 are provided, and embodiments of the anti-resonance panel 100 are provided that are combined with the fuselage skin 137 of the aircraft 145 to form an enclosed cabin 155. The anti-resonance panel 100 may be added to the aircraft 145 in addition or as an alternative with the positioning of a trim panel 154. For example, a stiffener member 108 may be incorporated into the base panel 102, which may enable broadband sound damping performance of the anti-resonance panel 100. Fig.14One embodiment of the reinforcement member 108 is provided; however, the reinforcement member 108 may be added to various locations throughout the enclosure 155. Fig.14 As shown, bonding the stiffener members 108 to the base panel 102 provides improved sound damping compared to the base panel 102 alone. Sound waves 109 are reflected from the anti-resonance panel 100. The anti-resonance panel 100 thus provides improved sound damping for the enclosure 155, particularly at low frequencies.

[0096] In some embodiments, sound insulation can be provided to the enclosure 155. Sound insulation can be provided to the enclosure 155 by positioning at least one anti-resonance panel 100 adjacent to the enclosure 155, the anti-resonance panel 100 comprising a base panel 102 and at least one stiffener member 108 attached to the base panel 102, wherein the at least one stiffener member 108 provides anti-resonance properties to the base panel 102 to reduce noise transmitted into the enclosure 155. In some embodiments, positioning at least one anti-resonance panel 100 adjacent to the enclosure 155 comprises positioning an anti-resonance panel 100 as previously described adjacent to the enclosure 155. In some embodiments, the at least one anti-resonance panel 100 can be coupled to the enclosure 155. In some embodiments, the at least one anti-resonance panel 100 can be coupled to the enclosure 155 using a grounding member 134.

[0097] exist Fig.15 An embodiment of effective anti-resonance performance is shown in FIG. Specifically, Fig.15 Exemplary predictions using finite element analysis (FEA) methods and experimental measurement results are shown. Fig.15 The performance shown in is representative only and is relative to the noise that can be blocked. Fig.15 The properties shown in are not intended to limit the present disclosure. Fig.15 The insertion loss performance of the anti-resonance panel 100 is shown (solid line) along with the matching FEA predictions (shown as diamonds). The dashed curve is the equivalent mass law prediction using equal mass density of an isotropic panel. Fig.15 As shown, the anti-resonance panel 100 can provide improved sound resistance, especially at relatively low frequencies, with equivalent mass density, and provide higher sound resistance than is seen. Fig.15 As shown, in this embodiment, the equivalent mass to achieve the shown noise loss is approximately sixteen (16) times that used in the anti-resonance panel 100. Other degrees of improvement are possible.

[0098] Fig.16 The effect of adding an exemplary inertial member 126 to the anti-resonance panel 100 to achieve wider bandwidth anti-resonance performance in an exemplary embodiment is shown. Fig.16 As shown, in some embodiments, the addition of the inertial member 126 (represented by a square) can provide a wider bandwidth of anti-resonance performance compared to embodiments without the inertial member 126 (represented by a triangle). In some embodiments, the addition of the inertial member 126 can reduce the reduction in anti-resonance performance seen in embodiments without the inertial member 126. The inertial member 126 generally helps to adjust the acoustic properties of the anti-resonance panel 100 to provide a wider bandwidth of anti-resonance performance. The inertial member 126 can define a new acoustic boundary 132 point, line or surface, and can enable the generation of a better defined anti-resonance panel 100. The inertial member 126 can help to shift the resonant frequency away from the target frequency range.

[0099] Fig.17 It is shown how the anti-resonance and double pane effects can be added together to attenuate very large acoustic frequency bandgaps. Specifically, Fig.17 An exemplary predicted transmission loss performance comparison using the dual pane effect between an untreated trim panel (dashed curve) (including base panel 102 and grounding member 134) and an anti-resonance trim panel (triangular markers) (including base panel 102, grounding member 134, and reinforcement member 108) is shown. For example, as shown in this embodiment, low frequency transmission loss performance can be increased, and any reduction in transmission loss can be transferred to higher frequencies, thereby providing improved sound insulation for lower frequencies.

[0100] Additionally, the present disclosure includes implementations according to the following clauses:

[0101] Item A1. An anti-resonance panel, comprising: a base panel, the base panel comprising a base panel core material and two base panel face sheets, each of the two base panel face sheets being adjacent to opposite sides of the base panel core material; and at least one reinforcement member positioned along the base panel in a defined area of ​​the base panel, the defined area being smaller than the entire area of ​​the base panel; wherein the at least one reinforcement member comprises a reinforcement member core material and two reinforcement member face sheets, the reinforcement member face sheets being adjacent to opposite sides of the reinforcement member core material.

[0102] Clause A2. The anti-resonance panel of Clause A1, wherein the at least one stiffener member is configured to provide anti-resonance performance to the base panel by adding stiffness to the defined area of ​​the base panel at a low mass density.

[0103] Clause A3. The anti-resonance panel of Clause A1 or A2, wherein the at least one stiffener member is disposed on one of the two base panel deck sheets.

[0104] Clause A4. The anti-resonance panel of Clause A1 or A2, wherein the at least one stiffener member is disposed between the two base panel face sheets and adjacent to the base panel core.

[0105] Clause A5. An anti-resonance panel according to any of clauses A1 to A4, wherein the at least one stiffener member is arranged along less than 25% of the total surface area of ​​the base panel and the mass of the at least one stiffener member is about 20% or less of the total mass of the anti-resonance panel.

[0106] Clause A6. The anti-resonance panel of any of Clauses A1 to A5, wherein the at least one stiffener member comprises two or more stiffener members, each stiffener member being positioned along the base panel in a respective defined area of ​​the base panel.

[0107] Clause A7. The anti-resonance panel of any of Clauses A1 to A6, wherein the stiffener member core material comprises polyethylene terephthalate (PET) foam, aramid honeycomb construction, or a combination thereof.

[0108] Clause A8. The anti-resonance panel of any of Clauses A1 to A7, wherein the stiffener member face sheet comprises carbon fiber, glass fiber, fiber composite, or a combination thereof.

[0109] Clause A9. The anti-resonance panel of any of clauses A1 to A8, wherein the anti-resonance panel is configured to reduce noise propagating through the anti-resonance panel at frequencies between about 300 Hz and about 1000 Hz.

[0110] Clause A10. The anti-resonance panel of any of Clauses A1 to A9, further comprising a perimeter stiffener member disposed along one or more edges of the at least one stiffener member.

[0111] Clause A11. The anti-resonance panel of any of Clauses A1 to A10, wherein the at least one stiffener member includes an inner wall defining a hollow portion therein.

[0112] Clause A12. The anti-resonance panel of any of clauses A1 to A11, further comprising at least one inertial member configured to provide an increase in mass over the defined area of ​​the anti-resonance panel.

[0113] Clause A13. The anti-resonance panel of clause A12, wherein the at least one inertial member has a mass density that is approximately 10 times greater than a mass density of the at least one stiffener member.

[0114] Clause A14. An anti-resonance panel according to clause A12 or A13, wherein the at least one inertial member comprises solid aluminum, rubber, tungsten, ceramic, or a combination thereof.

[0115] Clause A15. The anti-resonance panel of any of clauses A1 to A14, further comprising a reinforcing member disposed along a perimeter of the defined area of ​​the base panel and defining an acoustic boundary for the defined area of ​​the base panel.

[0116] Clause A16. The anti-resonance panel of any of clauses A1 to A15, further comprising a grounding member configured to anchor the anti-resonance panel to a structure and define an acoustic boundary for the defined area of ​​the base panel.

[0117] Clause A17. A system comprising: a structure; and an anti-resonance panel according to any of clauses A1 to A16 positioned adjacent to the structure.

[0118] Clause A18. The system of clause A17, wherein the structure comprises a fuselage skin of an aircraft.

[0119] Clause A19. An aircraft comprising an anti-resonance panel according to any of clauses A1 to A16.

[0120] Clause A20. The aircraft of clause A19, wherein the anti-resonance panel includes a ground contact member, wherein locations along a fuselage skin of the aircraft are anchor points for the ground contact member.

[0121] Clause A21. An aircraft according to clause A20, wherein the location is located at a window, a stringer and / or a peripheral frame portion.

[0122] Clause A22. The aircraft of clause A20 or A21, wherein the ground contact member couples the anti-resonance panel to the fuselage skin.

[0123] Clause A23. An aircraft according to any of clauses A19 to A22, wherein the anti-resonance panel is an inner side wall of the aircraft that at least partially defines an enclosed cabin.

[0124] Item B1. A system comprising: a structure; and at least one anti-resonance panel positioned adjacent to the structure to provide noise control for the structure, the at least one anti-resonance panel comprising: a base panel, the base panel comprising a base panel core and two base panel face sheets, each of the two base panel face sheets being adjacent to opposite sides of the base panel core, respectively; and at least one reinforcement member positioned along the base panel in a defined area of ​​the base panel, the defined area being smaller than the entire area of ​​the base panel; wherein the at least one reinforcement member comprises a reinforcement member core and two reinforcement member face sheets, the reinforcement member face sheets being adjacent to opposite sides of the reinforcement member core.

[0125] Clause B2. The system of clause B1, wherein the at least one anti-resonance panel further comprises a grounding member that anchors the at least one anti-resonance panel to the structure.

[0126] Clause B3. The system of clause B2, wherein the grounding member defines an acoustic boundary for the defined area of ​​the base panel.

[0127] Item C1. A method for manufacturing an anti-resonance panel having a base panel, the base panel having a base panel core and two base panel face sheets, each of the two base panel face sheets being respectively adjacent to opposite sides of the base panel core, the method comprising: attaching at least one reinforcement member along the base panel in a defined area of ​​the base panel, the at least one reinforcement member comprising a reinforcement member core and two reinforcement member face sheets, each of the two reinforcement member face sheets being respectively adjacent to opposite sides of the reinforcement member core, wherein the at least one reinforcement member is configured to provide anti-resonance performance to the base panel.

[0128] Clause C2. The method of clause C1, wherein attaching the at least one reinforcement member to the base panel comprises: composite layup, heat pressing, vacuum forming, vacuum bagging, vacuum assisted resin transfer molding (VARTM), or a combination thereof.

[0129] Clause C3. A method according to clause C1 or C2, wherein attaching the at least one reinforcement member to the base panel includes: incorporating at least one attachment mechanism for attaching the at least one reinforcement member to the base panel, the attachment mechanism comprising a screw, an adhesive, an adhesive film, a rivet or a combination thereof.

[0130] Clause C4. The method of any of clauses C1 to C3, further comprising: before attaching the at least one reinforcement member to the base panel, removing an inner portion of the at least one reinforcement member to create a hollow portion in the at least one reinforcement member.

[0131] Item D1. A method of providing sound insulation to an enclosed cabin, the method comprising: positioning at least one anti-resonance panel adjacent to the enclosed cabin, the at least one anti-resonance panel comprising a base panel and at least one reinforcement member attached to the base panel, wherein the at least one reinforcement member provides anti-resonance properties to the base panel to reduce noise transmitted into the enclosed cabin.

[0132] Clause D2. The method of clause D1, wherein positioning at least one anti-resonance panel adjacent to the structure comprises positioning an anti-resonance panel according to any of clauses A1 to A16 adjacent to the enclosure.

[0133] Clause D3. The method of clause D1 or D2, further comprising: coupling the at least one anti-resonance panel to the enclosure.

[0134] Clause D4. The method of clause D3, wherein coupling the at least one anti-resonance panel to the enclosure comprises coupling the at least one anti-resonance panel to the enclosure using a grounding member.

[0135] The word “exemplary,” when used herein, is intended to mean “serving as an example, example, or illustration.” Any implementation described herein as “exemplary” is not necessarily preferred or advantageous over other implementations.

[0136] As used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a reinforcement member" includes a plurality of such reinforcement members unless the context clearly dictates otherwise.

[0137] As used in the specification and the appended claims, reference to "on" encompasses both embodiments in which a component is disposed directly on another component and embodiments in which one or more intervening layers or elements are disposed between components.

[0138] With the benefit of the teachings presented in the foregoing description and the associated drawings, those skilled in the art to which these disclosures relate will appreciate the many modifications and other embodiments of the disclosures set forth herein. Although the drawings show only certain components of the devices and systems described herein, it should be understood that various other components may be used in conjunction with the supply management system. Therefore, it should be understood that the present disclosure is not limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. In addition, the steps in the method described above do not necessarily have to appear in the order shown in the drawings, and in some cases one or more of the steps shown may appear substantially simultaneously, or may involve additional steps. Although specific terms are employed herein, they are used only in a general descriptive sense and not for limiting purposes.

Claims

1. A method (1100) of manufacturing an anti-resonance panel (100) having a base panel (102), the base panel having a base panel core (104) and two base panel face sheets (106, 107), each of the two base panel face sheets being adjacent to opposite sides of the base panel core, the method comprising: At least one stiffener member (108) is attached (1110) along the base panel in a defined area (110) of the base panel, the at least one stiffener member comprising a stiffener member core (114) and two stiffener member face sheets (116, 117), each of the two stiffener member face sheets being adjacent to opposite sides of the stiffener member core, wherein the at least one stiffener member is configured to provide anti-resonance performance to the base panel by adding stiffness to the defined area of ​​the base panel at a low mass density.

2. The method (1100) of claim 1, wherein attaching (1110) the at least one reinforcement member (108) to the base panel (102) comprises: At least one of composite layup, heat pressing, vacuum forming, vacuum bagging, vacuum assisted resin transfer molding (1112), or a combination thereof.

3. The method of claim 1 , wherein attaching the at least one reinforcement member to the base panel comprises: At least one attachment mechanism is incorporated (1114) for attaching the at least one reinforcement member to the base panel, the attachment mechanism comprising screws, adhesive, adhesive film, rivets, or a combination thereof.

4. The method (1100) according to any one of claims 1 to 3, further comprising: Prior to attaching (1110) the at least one reinforcement member to the base panel (102), an inner portion (148) of the at least one reinforcement member (108) is removed (1109) to create a hollow portion (124) in the at least one reinforcement member.

5. A method of providing sound insulation to an enclosed cabin (155), the method comprising: at least one anti-resonance panel (100) is positioned adjacent to the enclosure, the at least one anti-resonance panel comprising a base panel (102) and at least one stiffener member (108) attached to the base panel, wherein the at least one stiffener member provides anti-resonance properties to the base panel by adding stiffness to a defined area of ​​the base panel at a low mass density to reduce noise transmitted into the enclosure, wherein positioning at least one anti-resonance panel adjacent to the enclosure (155) comprises positioning the anti-resonance panel (100) comprising: The base panel (102) includes a base panel core material (104) and two base panel face sheets (106, 107), each of the two base panel face sheets being adjacent to opposite sides of the base panel core material; and the at least one reinforcement member (108) being positioned along the base panel in a defined area (110) of the base panel, the defined area being less than the entire area (112) of the base panel, The at least one reinforcement member comprises a reinforcement member core material (114) and two reinforcement member face sheets (116, 117), wherein the reinforcement member face sheets are respectively adjacent to opposite sides of the reinforcement member core material.

6. The method according to claim 5, further comprising: The at least one anti-resonance panel (100) is coupled to the enclosure (155).

7. The method of claim 6, wherein coupling the at least one anti-resonance panel (100) to the enclosure (155) comprises: The at least one anti-resonance panel is coupled to the enclosure using a grounding member (134).

8. A system (200) comprising a structure (136) and at least one anti-resonance panel (100) positioned adjacent to the structure to provide noise control for the structure, the at least one anti-resonance panel comprising: a base panel (102) comprising a base panel core material (104) and two base panel face sheets (106, 107), each of the two base panel face sheets being adjacent to opposite sides of the base panel core material; and at least one reinforcement member (108) positioned along the base panel in a defined area (110) of the base panel, the defined area being less than the entire area (112) of the base panel, The at least one stiffener member comprises a stiffener member core (114) and two stiffener member face sheets (116, 117), the stiffener member face sheets being respectively adjacent to opposite sides of the stiffener member core, wherein the at least one stiffener member is configured to provide anti-resonance performance to the base panel by adding stiffness to the defined area of ​​the base panel at a low mass density.

9. The system (200) of claim 8, wherein the at least one anti-resonance panel (100) further comprises a grounding member (134) anchoring the at least one anti-resonance panel to the structure (136).

10. The system (200) of claim 9, wherein the grounding member (134) defines an acoustic boundary (132) for the defined area (110) of the base panel (102).

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