Pressure vessel having substantially flat panels

Abstract

The present invention relates to a pressure vessel having a substantially flat panel. The pressure vessel comprises at least one pair of side bulkheads spaced apart from each other. In addition, the pressure vessel comprises at least one substantially flat panel having at least one panel span extending between the pair of side bulkheads and adjacent to the side bulkheads in a non-contact manner. The panel and the side bulkheads together form at least a portion of a structural assembly enclosing the pressure vessel. The pressure vessel further comprises a plurality of panel supports that connect the side bulkheads to the panels at a plurality of panel attachment nodes distributed along the panel spans. At least two of the panel supports have different axial stiffnesses that are configured to cause the panel attachment nodes to deflect outwardly by substantially equal amounts when the panels are subjected to out-of-plane pressure loads during internal pressurization of the pressure vessel.

Description

Technical Field

[0001] The present disclosure relates generally to pressure vessel constructions and, more particularly, to pressure vessels having substantially planar panels. Background Art

[0002] Pressure vessels typically have a round or circular cross-sectional shape due to the efficiency with which a circular cross section carries internal pressurization loads. For example, internal pressurization of a spherical pressure vessel results in pure hoop tensile stresses and zero bending stresses in the vessel wall. Internal pressurization of a cylindrical pressure vessel results primarily in hoop tensile stresses in the cylindrical portion of the pressure vessel. For passenger aircraft with a cabin pressurized to a certain fraction of standard atmosphere, the fuselage typically has a circular cross-section, an elliptical cross-section, or a cross-section with multiple circular arcs due to the efficiency with which a cylindrical pressure vessel carries internal pressurization loads. Due to the structural efficiency of cylindrical pressure vessels, many pressurized aircraft are constructed as tube-and-wing aircraft.

[0003] A hybrid wing-body aircraft may have certain advantages over tube-wing aircraft in terms of aerodynamics and cargo carrying capacity. For example, the tubular fuselage of a tube-wing aircraft creates aerodynamic drag that reduces the fuel efficiency of the aircraft. In contrast, the center body of a hybrid wing-body aircraft has an aerodynamically shaped cross-section that creates lift in addition to the lift created by the wings. Thus, for certain aircraft sizes and range capabilities, a hybrid wing-body aircraft has a relatively high aerodynamic efficiency. In addition, the center body of a hybrid wing-body aircraft has a generally flat cross-sectional shape that provides a wide area for carrying passengers and / or cargo compared to the relatively narrow fuselage of a tube-wing aircraft.

[0004] However, the generally flat cross-sectional shape of a blended wing body aircraft presents challenges in terms of pressurization. As described above, the cabin of a passenger aircraft must generally be pressurized to a certain fraction of standard atmosphere. In addition, the structural components of the pressurized cabin must be designed to have predetermined safety factors. Therefore, in one embodiment, the cabin of a passenger aircraft may be designed for internal pressurization loads of 16 to 20 pounds per square inch (psi). When such internal pressurization loads are applied to a generally flat cross-sectional shape such as the center body of a blended wing body aircraft, the out-of-plane pressure loads on the flat panels of the center body may cause the panels to deflect outwardly at a relatively high curvature, resulting in large bending moments and large bending stresses. Large bending stresses may require increased structural mass for load-bearing capacity, which increases the gross weight of the blended wing body aircraft and reduces flight performance.

[0005] For panels defining the outer skin (e.g., upper skin) of the center body, high curvatures induced in the panels by out-of-plane pressure loads may disrupt the aerodynamics of the center body and reduce the aerodynamic performance of the aircraft. In addition, flight loads (e.g., in-plane tensile loads, compressive loads, and / or shear loads) on the panels may couple with the out-of-plane pressure loads, resulting in relatively high bending loads on the panels and requiring further increased structural mass for load-bearing capacity and resulting in a reduction in the effective load carrying capacity, fuel efficiency, and / or range of the hybrid wing-body aircraft.

[0006] As can be seen, there is a need in the art for a pressure vessel at least partially enclosed by substantially planar panels and having relatively high load bearing efficiency and wherein in-plane loads on the panels can be decoupled from out-of-plane pressure loads. Summary of the invention

[0007] The present disclosure specifically addresses and alleviates the above-mentioned needs associated with pressure vessels, and the present disclosure provides a pressure vessel having at least one pair of side bulkheads spaced apart from each other, and each side bulkhead having a bulkhead top portion. The pressure vessel includes at least one substantially flat panel having at least one panel span extending between the pair of side bulkheads and non-contactingly adjacent to the bulkhead top portion. The panel and the side bulkheads together form at least a portion of a structural assembly that encloses the pressure vessel. The pressure vessel includes a plurality of panel supports that connect the side bulkheads to the panels at a plurality of panel attachment nodes distributed along the panel spans. At least two of the panel supports have different axial stiffnesses, and the different axial stiffnesses are configured to cause the panel attachment nodes to deflect outwardly by substantially equal amounts when the panels are subjected to out-of-plane pressure loads during internal pressurization of the pressure vessel.

[0008] Also disclosed is a method for loading a pressure vessel, the method comprising internally pressurizing a pressure vessel at least partially surrounded by panels, the panels having at least one panel span extending between a pair of side bulkheads, each side bulkhead having a bulkhead top portion adjacent to the panels in a non-contacting manner. The method for loading a pressure vessel also comprises generating an out-of-plane pressure load on the panels in response to internally pressurizing the pressure vessel. Additionally, the method comprises transferring the out-of-plane pressure load from the panels to the side bulkheads using a plurality of panel supports, the plurality of panel supports connecting the side bulkheads to the panels at a plurality of panel attachment nodes distributed along the panels. The loading method also comprises limiting the panel attachment nodes to deflect outwardly by substantially equal amounts when the pressure vessel is internally pressurized, using a plurality of panel supports based on different axial stiffnesses between at least two of the panel supports.

[0009] In addition, a method for manufacturing a pressure vessel is disclosed. The method includes positioning a pair of side bulkheads in a spaced relationship from each other. The side bulkheads each have a bulkhead top portion. The manufacturing method also includes positioning a substantially flat panel non-contactingly adjacent to the bulkhead top portion so that at least one panel span extends between the pair of side bulkheads. The panel and the side bulkheads together form at least a portion of a structural assembly that encloses the pressure vessel. The manufacturing method also includes using a plurality of panel brackets to connect each of the side bulkheads to the panel at a plurality of panel attachment nodes distributed along the panel. As described above, at least two of the panel brackets have different axial stiffnesses, and when the panel is subjected to an out-of-plane pressure load during internal pressurization of the pressure vessel, the different axial stiffnesses cause or limit the panel attachment nodes to deflect outward by substantially equal amounts.

[0010] The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] These and other features of the present disclosure will become more apparent with reference to the accompanying drawings, wherein like reference numerals refer to like parts throughout, and wherein:

[0012] Figure 1 is a perspective view of an embodiment of a hybrid wing-body aircraft;

[0013] Figure 2 yes Figure 1 A top view of a hybrid wing body aircraft showing a pressurized passenger cabin and / or a pressurized cargo compartment representing an embodiment of the presently disclosed pressure vessel;

[0014] Figure 3 is along Figure 2 a cross-sectional view of a hybrid wing body aircraft taken along line 3-3 of FIG. 1 and showing a pressurized passenger cabin and / or a pressurized cargo compartment (e.g., a pressure vessel) defined by a pair of side bulkheads and a substantially flat panel extending between the pair of side bulkheads;

[0015] Figure 4 Is Figure 3 an enlarged view of a portion of a hybrid wing-body aircraft identified by reference numeral 4 and showing a plurality of panel brackets coupling the panels to the side bulkheads and the container ribs;

[0016] Figure 5 Is Figure 4 An enlarged view of a portion of a hybrid wing body aircraft, identified by reference numeral 5, and illustrating an embodiment of a plurality of panel brackets coupling the panels to the side bulkhead;

[0017] Figure 6 Is Figure 4An enlarged view of a portion of a hybrid wing body aircraft, identified by reference numeral 6, and showing an embodiment of a plurality of panel brackets coupling the panels to the container ribs;

[0018] Figure 7 is a perspective view of an embodiment of a pressure vessel having panels coupled to side bulkheads and vessel ribs by a plurality of panel brackets;

[0019] Figure 8 is a cross-sectional view of an embodiment of a portion of a hybrid wing body aircraft showing an embodiment of a pin connection at a panel bracket end of each panel bracket;

[0020] Fig. 9 Is Figure 8 An enlarged view of a portion of a hybrid wing-body aircraft identified by reference numeral 9 and showing an embodiment of a pin connection;

[0021] Fig.10 is along Fig. 9 A cross-sectional view taken along line 10-10 of FIG. 1 and further illustrating an embodiment of a pin connector;

[0022] Fig.11 is a cross-sectional view of an embodiment of a portion of a hybrid wing body aircraft, showing an embodiment of a rigid connector;

[0023] Fig.12 Is Fig.11 an enlarged view of a portion of the hybrid wing body aircraft indicated by reference numeral 12 and showing the rigid connections between each panel bracket and the panel and the pin connections at the container ribs;

[0024] Fig.13 Is Fig.11 an enlarged view of a portion of the hybrid wing body aircraft indicated by reference numeral 13 and showing the rigid connections between each panel bracket and the panel and the pin connections at the side bulkheads;

[0025] Fig.14 An embodiment of a pressure suppression mechanism between a panel and a side bulkhead is shown, and wherein the pressure suppression mechanism is constructed as a block of elastomeric material;

[0026] Fig.15 An embodiment of a pressure suppression mechanism configured as a plate seal assembly having a sealing member configured as a sealing strip is shown;

[0027] Fig.16 Another embodiment of a sealing member configured as an O-ring seal is shown;

[0028] Fig.17A portion of an embodiment of a pressure vessel is shown wherein panel attachment nodes are evenly spaced and panel supports are shown having an axial stiffness that gradually increases in a direction from a side support to mid-span of a panel and panel supports are shown that are formed of a common material but have different cross-sectional areas;

[0029] Fig.18 A portion of an embodiment of a pressure vessel is shown wherein panel attachment nodes are evenly spaced and a panel support having an axial stiffness that gradually increases in a direction from a side support to mid-span of a panel and panel supports having the same cross-sectional area but formed of different materials are shown;

[0030] Fig.19 A portion of an embodiment of a pressure vessel is shown wherein panel attachment nodes are non-uniformly spaced and a panel support closest to a side bulkhead is also shown having increased axial stiffness relative to the remaining panel supports;

[0031] Fig. 20 An embodiment that is a portion of a pressure vessel having increased outward deflection of a panel at a panel attachment node of a failed support;

[0032] Fig.21 is a cross-sectional view of an embodiment of a panel support comprised of back-to-back channels providing a fail-safe configuration;

[0033] Fig. 22 is a cross-sectional view of an embodiment of a pressure vessel having slightly curved panels;

[0034] Fig.23 is a top view of an embodiment of a pressure vessel having vessel ribs arranged in an orthogonal pattern;

[0035] Fig.24 is a top view of an embodiment of a pressure vessel having vessel ribs that are oriented non-parallel to each other and / or to side bulkheads;

[0036] Fig.25 is a cross-sectional view of a 2-inch thick panel supported by 6 strength brackets sized for axial strength;

[0037] Fig.26 is a cross-sectional view of a 2-inch thick panel supported by 12 strength braces sized for axial strength;

[0038] Fig. 27 is a cross-sectional view of a 4-inch thick panel supported by 12 strength braces sized for axial strength;

[0039] Fig.28is a graph of skin thickness versus spanwise position for two (2) sandwich panels having two (2) different panel thicknesses and both supported by 10 strength braces and both subjected to out-of-plane pressure loading;

[0040] Fig.29 is a graph of skin thickness versus spanwise position for three (3) sandwich panels comprising Fig.28 The two (2) sandwich panels shown in and also include 6 inch thick panels without strength braces;

[0041] Fig.30 is a graph of total weight per unit area versus panel thickness for several panel configurations;

[0042] Fig.31 is a cross-sectional view of an embodiment of a panel supported by four panel supports adjusted for axial stiffness;

[0043] Fig.32 is a cross-sectional view of an embodiment of a panel supported by 12 panel supports adjusted for axial stiffness;

[0044] Fig.33 is a graph of total panel weight versus panel thickness for several panel configurations;

[0045] Fig.34 is a cross-sectional view of an embodiment of a panel supported by 12 panel supports and subjected to out-of-plane pressure loads and in-plane buckling loads;

[0046] Fig.35 is a flow chart of operations included in a method of loading a pressure vessel; and

[0047] Fig.36 is a flow chart of operations included in a method of manufacturing a pressure vessel. DETAILED DESCRIPTION

[0048] Referring now to the accompanying drawings which show preferred and various embodiments of the present disclosure, Figure 1 1 is a perspective view of an embodiment of a hybrid wing body aircraft 100. The aircraft includes a center body 110 and a pair of wings 102 extending outwardly from the center body 110. The aircraft 100 may also include a pair of vertical stabilizers 104 located on the rear portion of the center body 110. The aircraft additionally includes a propulsion unit 106, which in the embodiment shown is mounted on a pylon protruding upwardly from the rear end of the aircraft 100.

[0049] Figure 21 is a top view of the hybrid wing body aircraft 100, showing the payload bay 108 in the center body 110. In one embodiment, the payload bay 108 can be configured as a passenger cabin 112 and / or a cargo cabin 114, and can be internally pressurized, so that the payload bay 108 represents an embodiment of the pressure vessel 200 as currently disclosed. Advantageously, the relatively wide shape of the center body 110 allows the payload bay 108 to carry a large number of passengers and / or to carry cargo with a relatively large width. However, the payload bay 108 can be configured for any of a variety of applications.

[0050] Although the presently disclosed pressure vessel 200 is described in the context of the passenger cabin 112 and / or cargo hold 114 of the hybrid wing body aircraft 100, the pressure vessel 200 may be implemented for use in any of a variety of applications. For example, the pressure vessel 200 may be implemented for use in marine vessels, land-based structures and vehicles, air transport applications (e.g., any type of aircraft), and space applications. Furthermore, the pressure vessel 200 may be configured to contain any of a variety of fluids including liquids and / or gases, and is not limited to internal pressurization 470 via air pumped into the passenger cabin 112 or cargo hold 114 of the aircraft.

[0051] Reference Figures 2 to 3 The pressure vessel 200 includes at least one pair of side bulkheads 206 spaced apart from each other. Each side bulkhead 206 has a bulkhead top portion 210 ( Figures 4 to 5 ) and the bottom portion 212 of the partition wall ( Figure 4 ). In addition, the pressure vessel 200 includes at least one substantially planar panel 300 having at least one panel span 324 extending between the side bulkheads 206. Fig.18 In an alternative embodiment shown in FIG. 3 , the panel 300 may be slightly curved. Figure 3 As shown, the panel 300 may be a top panel 320 or an upper skin panel of the center body 110 and may define the aerodynamic surface 116 of the aircraft. In this regard, the panel 300 may be configured to withstand pressure other than that caused by the internal pressurization 470 ( Figure 4 ) on the panel 300. Such flight loads on the panel 300 may include in-plane loads, such as compressive loads, tensile loads, and / or shear loads acting on the panel 300 due to bending of the wing 102, aerodynamic forces on the center body 110, and / or other flight loads.

[0052] The top panel 320 is positioned non-contactingly adjacent to the bulkhead top portion 210 of each side bulkhead 206, which results in a panel bulkhead gap 214 between the panel 300 and each bulkhead top portion 210. The top panel 320 and the side bulkheads 206 together form at least a portion of the structural assembly 198 that encloses the pressure vessel 200. For example, as Figure 3 As shown, the structural assembly 198 may include at least a pair of side bulkheads 206 , a top panel 320 , and a bottom panel 322 that may extend between the side bulkheads 206 .

[0053] exist Figures 2 to 3 In the embodiment, the pressure vessel 200 may include one or more vessel ribs 230 located between the side bulkheads 206. Each vessel rib 230 has a rib top portion 232 and a rib bottom portion 234. The panel 300 is non-contactingly adjacent to the rib top portion 232 of each vessel rib 230, which results in a panel rib gap 236 ( Figure 3 ). The container ribs 230 may divide the top panel 320 into two or more panel spans 324, each of which has a width shorter than a width of a single panel span (not shown) extending between the side bulkheads 206. The container ribs 230 may also divide the bottom panel 322 into two or more panel spans 324. As described below, the container ribs 230 may improve the structural efficiency of the pressure vessel 200.

[0054] Reference Figures 4 to 6 , Figure 4 It is shown in Figures 1 to 3 , and showing a plurality of panel brackets 400 coupling the side bulkheads 206 and the vessel ribs 230 to the top panel 320 at a plurality of panel attachment nodes 342 distributed along the panel span 324. Importantly, the use of the panel brackets 400 to attach the side bulkheads 206 and the vessel ribs 230 to the top panel 320 greatly reduces the relatively large bending moments that the top panel 320 would otherwise be subjected to if the top panel 320 were directly attached to the side bulkheads 206 and / or the vessel ribs 230. In addition, the panel brackets 400 can decouple out-of-plane pressure loads (e.g., due to internal pressurization 470 of the pressure vessel 200) and in-plane loads (e.g., due to flight loads), which can improve the structural efficiency of the pressure vessel 200, as described below. Figure 4 As shown, each panel bracket 400 has opposing bracket ends 450. One of the bracket ends 450 of each panel bracket 400 is attached to the panel attachment node 342, and the remaining bracket ends 450 of each panel bracket 400 are attached to the side bulkhead 206 at the bulkhead attachment node 216, or to the container rib 230 at the rib attachment node 238. Figure 5In the embodiment shown, the bracket ends 450 of the panel brackets 400 are attached to the common bracket bulkhead attachment location 218 on the bulkhead top portion 210, which can simplify manufacturing. However, in embodiments not shown, the bracket ends 450 of two or more of the panel brackets 400 can be attached to different attachment locations that can be vertically spaced apart along the side bulkhead 206.

[0055] exist Figure 4 , the bottom panel 322 may be directly coupled to the side bulkheads 206. For example, the bulkhead bottom portion 212 of one or more of the side bulkheads 206 may be directly coupled to the bottom panel 322, so that bending loads in each side bulkhead 206 (e.g., due to the internal pressurization 470 of the pressure vessel 200) are transferred to the bottom panel 322. Similarly, the rib bottom portion 234 of one or more of the vessel ribs 230 may be directly coupled to the bottom panel 322. However, in embodiments not shown, the bottom panel 322 may be coupled to the side bulkheads 206 and / or the vessel ribs 230 using a plurality of panel brackets 400 that are constructed and arranged in a manner similar to the plurality of panel brackets 400 that couple the top panel 320 to the side bulkheads 206, and this may reduce or prevent bending loads in the side bulkheads 206 and the bottom panel 322 (e.g., due to the internal pressurization 470) from being transferred between each other. The top panel 320 (i.e., not supported by the panel support 400) can have a substantially uniform bending stiffness. For example, the bending stiffness at all locations of the top panel 320 can be within 20% of each other. However, in other embodiments, the bending stiffness can vary by more than 20% at different locations on the top panel 320.

[0056] like Figures 4 to 6 As shown and described in more detail below, in the presently disclosed pressure vessel 200, at least two of the panel supports 400 that couple the panels 300 (e.g., top panels) to the side bulkheads 206 have different axial stiffnesses that are configured to cause the panel attachment nodes 342 to deflect outwardly by substantially equal deflection amounts 346 when the panels 300 are subjected to out-of-plane pressure loads during internal pressurization 470 of the pressure vessel 200. As described below, the difference in axial stiffness between two or more of the panel supports 400 can be achieved by varying the cross-sectional area of ​​the two or more panel supports 400. Alternatively or additionally, the difference in axial stiffness between two or more of the panel supports 400 can be achieved by varying the elastic modulus (e.g., elastic modulus or Young's modulus), as described in more detail below.

[0057] Advantageously, when the pressure vessel 200 is unpressurized, the substantially equal outward deflection of the panel attachment nodes 342 can maintain or preserve the profile of the panel 300 (e.g., Figure 4 The plan shape of the top panel 320; Fig.18 320 in the slightly curved shape of the top panel 320). Maintaining or maintaining the profile of the panel 300 during the internal pressurization 470 of the pressure vessel 200 is useful for applications where the panel 300 (e.g., the top panel 320) is used, for example, in Figures 1 to 3 The aerodynamic surface 116 ( Figures 2 to 3 ) can be advantageous, as described in more detail below. As described above, the panel support 400 can decouple the out-of-plane pressure loads and the in-plane loads, which can improve the structural efficiency of the pressure vessel 200. The decoupling of the out-of-plane pressure loads and the in-plane loads greatly reduces the relatively large bending moments that the panel 300 would otherwise need to carry if the panel 300 was directly attached to the side bulkhead 206 and / or the vessel rib 230.

[0058] As described above, the pressure vessel 200 includes side bulkheads 206 arranged in spaced relationship with one another. Figure 2 The side bulkheads 206 are shown extending along the longitudinal direction 120 of the payload bay 108. Each of the side bulkheads 206 may be substantially straight and planar, such as Figures 2 to 4 However, the side bulkheads 206 may each have a non-straight and / or non-planar shape (not shown). Although shown as being vertically oriented and parallel to one another, the side bulkheads 206 may be non-vertically oriented and / or may not be parallel to one another. The pressure vessel 200 may include one or more additional bulkheads to enclose the pressure vessel 200. For example, Figure 2 An end bulkhead 208 is shown located on at least one of the opposing ends of the payload bay 108 and extending along the lateral direction 118 to close the end of the pressure vessel 200. The end bulkhead 208 on at least one end of the pressure vessel 200 can be directly coupled to the side bulkheads 206 and the bottom panel 322. Additionally, in any embodiments of the pressure vessel 200, the end bulkhead 208 can be coupled to the top panel 320 via a plurality of panel brackets 400 in an arrangement similar to the panel brackets 400 that couple the top panel 320 to the side bulkheads 206.

[0059] As described above, the pressure vessel 200 may include a Figure 4 At least one container rib 230 is shown between the pair of side partitions 206. For example, Figures 2 to 4The illustrated pressure vessel 200 has two (2) container ribs 230 that are positioned equidistantly between each other and the side bulkhead 206. However, the pressure vessel 200 may include any number of container ribs 230, and the container ribs 230 may be positioned equidistantly or non-equidistantly between each other and the side bulkhead 206. Each of the container ribs 230 may be substantially straight and planar, as shown in the accompanying drawings, although non-straight and / or non-planar shapes are contemplated for the container ribs 230. Each container rib ... Figure 2 206. However, in other embodiments described below ( Fig.24 ) in which the pressure vessel 200 may include one or more vessel ribs 230 oriented in a non-parallel relationship to one or more of the side bulkheads 206.

[0060] Reference Figure 4 As described above, the pressure vessel 200 includes at least one substantially flat panel 300 (eg, a top panel) having a plurality of substantially flat panels 300 disposed between the side bulkheads 206 in the transverse direction 118 ( Figure 2 ) at least one panel span 324 extending between the side bulkheads 206. A panel 300 for a pressure vessel 200 without a container rib 230 (not shown) may include a single panel span 324 extending between the side bulkheads 206 in the transverse direction 118. For a pressure vessel 200 (not shown) with a single container rib 230, the panel 300 may be divided into two panel spans 324, each panel span extending between the side bulkheads 206 and the container rib 230. Figures 2 to 4 In the pressure vessel 200 shown in FIG. 1 having two (2) container ribs 230, the panel 300 can be divided into three (3) panel spans 324, two (2) of which extend between the side bulkhead 206 and one of the container ribs 230, and the remaining panel span 324 extends between two (2) container ribs 230. Each panel span 324 has opposite panel side portions 326 and a panel center portion 330 located between the panel side portions 326.

[0061] like Figure 4 and Figure 6 As shown, each container rib 230 may be coupled to the panel 300 using a plurality of panel brackets 400. The plurality of panel brackets 400 may extend from the rib top portion 232 of each container rib 230 to a corresponding plurality of panel attachment nodes 342 distributed along the panel span 324 on opposite sides of the container rib 230. Figure 6The bracket ends 450 of the panel brackets 400 are shown attached to a common bracket rib attachment location 240 on the rib top portion 232. However, in other embodiments not shown, the bracket ends 450 of two or more of the panel brackets 400 may be attached to different attachment locations spaced vertically apart along the container rib 230.

[0062] As described above, for the plurality of panel supports 400 coupling the panels 300 to the side bulkheads 206 and for the plurality of panel supports 400 coupling the panels 300 to one or more vessel ribs 230 and / or one or more end bulkheads 208, at least two of the panel supports 400 have unique axial stiffnesses that cause the panel attachment nodes 342 to deflect outwardly by substantially equal amounts 346 when the panels 300 are subjected to uniform out-of-plane pressure during internal pressurization 470 of the pressure vessel 200. For example, Figure 5 The panel bracket 400 that couples the side bulkhead 206 to the top panel 320 may have a unique axial stiffness that causes the panel attachment node 342 to deflect outwardly with respect to the panel attachment node 342. Figure 6 400 is coupled to the vessel rib 230 via the panel support 400. In one embodiment, during internal pressurization 470 of the pressure vessel 200, the outward deflection of any panel attachment node 342 along the panel 300 can be within 20%, and more preferably within 10%, of the outward deflection of any other panel attachment node 342 of the panel 300. Advantageously, the panel attachment nodes 342 divide the panel 300 into a plurality of panel segments 332 as described above. Each panel support 400 has an axial stiffness that is configured to force or limit the outward deflection of the panel attachment node 342. Limiting the outward deflection of the panel attachment node 342 via the panel support 400 reduces the magnitude of the allowable buckling load on the panel 300 relative to the buckling load that would otherwise occur without the panel support 400. The buckling load can be described as the compressive load at which the panel 300 is at which it will buckle.

[0063] A technical effect of including the vessel ribs 230 may be an improvement in the structural efficiency of the pressure vessel 200. For example, as described above, including the vessel ribs 230 in the pressure vessel 200 divides the panel 300 into two or more panel spans 324, each of which has a width that is shorter than the width of a single panel span 324 that would extend between the side bulkheads 206 of the pressure vessel 200 without the vessel ribs 230. The reduction in the width of the panel spans 324 allows for a reduction in the length and therefore weight of the panel support 400 that would otherwise need to extend from each side bulkhead 206 to the panel center portion 330 of the single panel span 324 extending between the side bulkheads 206.

[0064] Refer again Figure 4 , on each side of the pressure vessel 200 (e.g., proximate the side bulkhead 206), the panel side portion 326 may overlap the side bulkhead 206 and extend toward the outside 202 of the pressure vessel 200. For example, the top panel 320 may overlap the side bulkhead 206 on each side of the pressure vessel 200 and may define at least a portion of an upper skin panel (not shown) of one of the wings 102. Alternatively, in an embodiment not shown, the panel side portion 326 on each side of the pressure vessel 200 may terminate at a location directly above the side bulkhead 206. In yet another embodiment not shown, each panel side portion 326 may terminate at a location on the inside 204 of the side bulkhead 206.

[0065] Figure 7 is a perspective view of an embodiment of a pressure vessel 200 having a pair of side bulkheads 206 and a pair of vessel ribs 230, each of which extends in the longitudinal direction 120, and each of which is coupled to the top panel 320 via a plurality of panel brackets 400. In the illustrated embodiment, the panel attachment nodes 342 may be uniformly spaced along the transverse direction 118 of the pressure vessel 200 and / or along the longitudinal direction of the pressure vessel 200. However, in other embodiments, the panel attachment nodes 342 may be non-uniformly spaced along the transverse direction 118 and / or the longitudinal direction 120 of the top panel 320. Regardless of the spacing, the panel attachment nodes 342 may define a two-dimensional pattern along the top panel 320. The panel brackets 400 may be arranged at a plurality of bracket-bulkhead attachment locations 218 ( Figure 4 ) is attached to each side bulkhead 206.

[0066] The panel bracket 400 may be disposed at a plurality of bracket rib attachment locations 240 ( Figure 4 ) is attached to each container rib 230. For example, Figure 7 The arrangement of the panel supports 400 shown in FIG. 1 may be repeated at spaced intervals along the longitudinal direction 120 of the pressure vessel 200. As described above, Figure 7 Two or more of the panel supports 400 that couple the panel 300 to the side bulkhead 206 and the vessel rib 230 may have unique axial stiffness, and the interior of the pressure vessel 200 is pressurized 470 ( Figure 4 ), when the panel 300 is subjected to an out-of-plane pressure load, the unique axial stiffness is configured to cause the two-dimensional pattern of panel attachment nodes 342 to deflect outwardly by substantially equal deflection amounts 346 (e.g., Figures 5 and 6 ).

[0067] Because the panel attachment nodes 342 deflect outwardly by substantially equal amounts, the panels 300 experience reduced bending stresses when under out-of-plane pressure loads relative to the bending stresses that would otherwise occur during internal pressurization 470 of the pressure vessel 200 without the panel brackets 400 and with the panels 300 coupled directly to the side bulkheads 206 and vessel ribs 230 (if included). Due to the reduced bending stresses in the panels 300, the in-plane and out-of-plane pressure loads on the panels 300 are effectively decoupled. In a hybrid wing body aircraft such as the 100 ( Figures 1 to 3 ), the flight loads (e.g., in-plane tensile loads, in-plane compressive loads, and / or in-plane shear loads) on the panel 300 of the center body 110 can be decoupled from the out-of-plane pressure loads on the panel 300. The decoupling of the out-of-plane pressure loads and the in-plane loads allows the panel 300 to be lighter in weight due to the reduction of the bending loads on the panel 300. The reduced weight of the panel 300 can result in improved operational performance, such as increased range, fuel efficiency, climb rate, payload capacity, and other performance improvements. In addition, the panel bracket 400 can reduce or prevent changes in the aerodynamic shape or profile of the panel 300 that would otherwise occur in the absence of the panel bracket 400. In this regard, the panel bracket 400 can cause the panel 300 to deflect outwardly by a uniform amount across the length and / or width of the panel 300, and can thereby maintain the aerodynamic shape of the center body 110 during internal pressurization 470, which can maintain the aerodynamic performance of the hybrid wing body aircraft 100.

[0068] Reference Figures 8 to 10 , Figure 8 An embodiment of a portion of a blended wing body aircraft 100 is shown in , which shows an embodiment of a pin connection 452 coupling each of the panel brackets 400 to the panel 300 as well as the side bulkhead 206 and the container rib 230 . Fig. 9 is an enlarged view of an embodiment of a pin connection 452 that attaches the bracket end 450 of each panel bracket 400 to the panel attachment node 342. The remaining bracket end 450 of each panel bracket 400 is coupled to a common bracket rib attachment location 240. For example, Fig.10 An embodiment of a pin connection 452 is shown coupling the bracket end 450 of each panel bracket 400 to the rib attachment node 238 at the rib top portion 232 of the container rib 230. The pin connection 452 at each panel attachment node 342 allows the panel 300 to rotate relative to the panel bracket 400. Similarly, the pin connection 452 at the rib attachment node 238 allows the panel bracket 400 to rotate relative to the container rib 230. Figures 9 and 10In the embodiment of the present invention, the pin connector 452 may include a bracket attached to the rib top portion 232. The bracket may include a common pin extending through the bracket end 450 of the panel bracket 400. Although in Fig.10 1, but one or more of the panel brackets 400 may include snap-fitting buckles at some point along the length of the panel bracket 400 to allow the panel attachment nodes 342 to align with each other in the lateral direction 118, such as Figure 7 shown. Fig. 9 The pin connection 452 shown in FIG. 4 represents the general concept of a joint that allows the panel bracket 400 to rotate relative to the panel attachment node 342 and / or allows the panel bracket 400 to rotate relative to the container rib 230 (or relative to the side bulkhead 206- Figure 8 ) rotation, and is not intended to limit alternative structural configurations of pin connectors 452 that may be included with the pressure vessel 200. In this regard, the pressure vessel 200 may include one or more pin connectors 452 having any of a variety of alternative structural configurations, such as different edge distances for pins (not shown) extending through the pin connectors, and / or the bracket end 450 of each of the panel brackets 400 may have any of a variety of different structural configurations.

[0069] Reference Figures 11 to 13 , Fig.11 , an embodiment of a portion of a blended wing body aircraft 100 is shown showing an embodiment of a rigid connection 454 coupling the panel bracket 400 to the panel 300. Pin connections 452 connecting the panel bracket 400 to the side bulkhead 206 and the container rib 230 are also shown. Fig.12 An embodiment of a rigid connector 454 is shown at each panel attachment node 342 for coupling the panel 300 to the bracket end 450 of each panel bracket 400. Also shown is a pin connector 452 coupling the bracket end 450 of each panel bracket 400 to a common bracket rib attachment location 240 on the rib top portion 232 of the container rib 230. Fig.13An embodiment of a rigid connector 454 at each panel attachment node 342 is shown for coupling the panel 300 to the panel bracket 400, and a pin connector 452 is also shown coupling the bracket end 450 of each panel bracket 400 to the common bracket bulkhead attachment location 218 on the bulkhead top portion 210 of the side bulkhead 206. The rigid connector 454 at the panel attachment node 342 may tend to prevent the panel 300 from rotating relative to the panel bracket 400 by providing a moment restraint to the panel 300 at the rigid connector 454. In one embodiment, the rigid connector 454 may include a mechanical fastener and / or an adhesive that couples the bracket end 450 to the panel 300. For example, the panel 300 may be configured as a monocoque panel 314 having a skin member 316 coupled to a plurality of stringers 318 that may be spaced apart from one another. The bracket end 450 of the panel bracket 400 may be mechanically fastened to the stringer 318.

[0070] Fig.13 Also shown are embodiments of pin connectors 452 that couple the bracket end 450 of each panel bracket 400 to a common bracket bulkhead attachment location 218 on the bulkhead top portion 210 of the side bulkhead 206. The selection of a pin connector 452 or a rigid connector 454 for attaching the panel bracket 400 to the panel 300 and / or the side bulkhead 206 or container rib 230 may depend, at least in part, on the magnitude and / or type of loads at the connector during outward deflection of the panel 300. For example, if it is determined that a rigid connector 454 will cause excessively high bending moments on the panel 300 or on the panel bracket 400 during outward deflection of the panel 300, a pin connector 452 may be selected to attach the panel bracket 400 to the panel attachment node 342. Alternatively, if relatively high axial loads must be transferred between the panel support 400 and the panel 300 or the side bulkhead 206 or the vessel rib 230 during outward deflection of the panel 300, a rigid connector 454 may be selected for attaching the panel support 400 to the panel attachment node 342 or the side bulkhead 206 or the vessel rib 230. In any of the embodiments of the pressure vessel 200 disclosed herein, the rigid connector 454 and / or the pin connector 452 may be used in any one or more locations to attach the panel support 400 to the side bulkhead 206 and / or the vessel rib 230. However, the connectors used to couple the panel support 400 to the panel 300, the side bulkhead 206, and the vessel rib 230 may be provided with any degree of rotatability, including a range from non-rotatable connectors (e.g., strictly rigid connectors) to fully rotatable connectors (e.g., pin connectors 452).

[0071] Still refer to Fig.13, the pressure vessel 200 may include a pressure suppression mechanism 472 along each of the side bulkheads 206 for sealing the side bulkheads 206 to the panel 300 to prevent internal pressure from escaping from the pressure vessel 200. The pressure suppression mechanism 472 may be configured to allow the panel 300 to deflect outward while the interior of the pressure vessel 200 is pressurized 470 ( Figure 4 ) without losing internal pressure during the process. In addition, the pressure suppression mechanism 472 can optionally be configured to allow the panel 300 to be moved along the lateral direction 118 ( Figure 7 ) movement, which may occur due to in-plane loads on the panel 300 and / or due to thermal expansion or contraction of the panel 300 along an in-plane direction. Fig.13 In the embodiment of the present invention, the pressure suppression mechanism 472 can be configured to extend along the longitudinal direction 120 ( Figure 7 ) extending from the panel 300. In some embodiments, the pressure diaphragm 474 can be a sheet of elastomeric or flexible material (e.g., rubber, silicone, plastic) that is configured to accommodate relative movement of the panel 300 at least in an out-of-plane direction during internal pressurization 470 of the pressure vessel 200. The pressure diaphragm 474 can be adhesively bonded and / or mechanically coupled or fastened to the panel 300 and the bulkhead top portion 210 of each side bulkhead 206. The length of the pressure diaphragm 474 is long enough to allow the panel 300 to move up and down (e.g., in an out-of-plane direction) due to out-of-plane pressure loads. Fig.13 ), but is small enough to adequately span the gap between the side bulkhead 206 and the panel 300.

[0072] Reference Fig.14 In another embodiment, the pressure suppression mechanism 472 may include a block 476 of elastomeric material installed between the bulkhead top portion 210 and the panel 300. The block 476 of elastomeric material may extend continuously along the longitudinal direction of the side bulkhead 206. For example, a block 476 of closed-cell foam may be compressed and installed between the bulkhead top portion 210 and the panel 300. The foam may accommodate the outward deflection of the panel 300 while maintaining the internal pressure within the pressure vessel 200. Although not shown, the block 476 of elastomeric material may also be installed between the panel 300 and the pressure vessel 200. Figure 2 )between.

[0073] Reference Figure 15 to Figure 16 In another embodiment, the pressure suppression mechanism 472 may be configured as a plate seal assembly 478 that extends continuously in the longitudinal direction of the side bulkhead 206. A similar arrangement of the plate seal assembly 478 may be provided along one or more end bulkheads 208 ( Figure 2 ) installation, the pressure vessel 200 may optionally include one or more end bulkheads. Figure 15 to Figure 16The plate sealing assembly 478 in the embodiment may include a first plate 480 extending downward from the panel 300, a second plate 482 extending upward from the bulkhead top portion 210, and a sealing member 484 installable between the first plate 480 and the second plate 482. The sealing member 484 may be retained with the first plate 480 or the second plate 482, and may be configured to sealingly engage the respective surfaces of the second plate 482 or the first plate 480.

[0074] For example, Fig.15 A sealing member 484 is shown that is configured as a sealing strip 486 formed of a material that abuts against a surface of the second plate 482. The sealing strip 486 may be formed of an elastomeric material, a polymeric material, a ceramic material, a metallic material, or any combination thereof. The plate sealing assembly 478 may include one or more spring mechanisms 488, such as a series of compression springs disposed within a series of holes (not shown) arranged at spaced intervals along the length of the first plate 480. The spring mechanism 488 may be configured to constantly push the sealing strip 486 against the surface of the second plate 482 to maintain the internal pressure within the pressure vessel 200. The sealing strip 486 is configured to slide along the surface of the second plate 482 to accommodate outward deflection of the panel 300 during internal pressurization 470 of the pressure vessel 200. In an alternative embodiment, Fig.16 A sealing member 484 is shown that is configured as a ball seal 490, such as an O-ring seal, that is retained within a groove formed along the longitudinal direction of the first plate 480. An exposed portion of the ball seal 490 can sealingly engage the surface of the second plate 482 in a manner that maintains the internal pressure within the pressure vessel 200 while accommodating outward deflection of the panel 300. Any of a variety of alternative arrangements can be implemented to provide a pressure seal between the side bulkhead 206 and the panel 300 while still allowing the panel 300 to move vertically relative to the side bulkhead 206.

[0075] Reference Figure 17 to Figure 18 , in each figure a portion of an embodiment of a pressure vessel 200 is shown having a plurality of panel supports 400 coupling the panels 300 to the side bulkheads 206. As is known in the art, the axial stiffness k of an element may be expressed as:

[0076] k=AE / L

[0077] Where A is the cross-sectional area of ​​the element, E is the elastic modulus of the element material (i.e., elastic modulus or Young's modulus), and L is the length of the element. Given the above stiffness equation, the axial stiffness k of the panel support 400 can be changed by changing the cross-sectional area A and / or by changing the elastic modulus E (e.g., a mechanical property of the material) of the panel support 400 and / or by changing the length L of the panel support 400. However, for a given geometric arrangement of the pressure vessel 200, the length L of each of the panel supports 400 is fixed, leaving the other two variables (i.e., cross-sectional area A and elastic modulus E) to be specified for configuring the axial stiffness of each panel support 400.

[0078] Fig.17 An embodiment is shown in which the panel attachment nodes 342 are evenly distributed or spaced apart along the panel 300. For example, Figure 4 In the arrangement shown, the panel attachment nodes 342 may be evenly distributed along each panel span 324. Fig.17 , the panel bracket 400 is formed of a common material (eg, aluminum, steel, etc.) and thus has the same elastic modulus E. Fig.17 The axial stiffness of the panel support 400 in the embodiment can be changed by configuring the panel support 400 to have different cross-sectional areas. For example, Fig.17 A first panel support 402 having a first cross-sectional area 412, a second panel support 404 having a second cross-sectional area 414, a third panel support 406 having a third cross-sectional area 416, a fourth panel support 408 having a fourth cross-sectional area 418, and a fifth panel support 410 having a fifth cross-sectional area 420 are shown. In one embodiment, the fifth panel support 410 may have an axial stiffness greater than the axial stiffness of the fourth panel support 408, which may have an axial stiffness greater than the axial stiffness of the third panel support 406, which may have an axial stiffness greater than the axial stiffness of the second panel support 404, which may have an axial stiffness greater than the axial stiffness of the first panel support 402. This arrangement may result in substantially uniform outward deflection of the panel attachment nodes 342 when the panels 300 are subjected to out-of-plane pressure loads due to internal pressurization 470 of the pressure vessel 200. Using finite element analysis or other analytical means, the cross-sectional areas of the panel supports 402 , 404 , 406 , 408 , and 410 may be repeated until the vertical deflection of the panel 300 at each of the panel attachment nodes 342 is substantially the same.

[0079] Fig.18 Another embodiment is shown, in which similar to Fig.17 , the panel attachment nodes 342 are located along each panel span 324 ( Figure 4 ) are evenly spaced. Fig.18 , the panel supports 400 have the same cross-sectional area, but are formed of different materials having correspondingly different elastic moduli, and the resulting panel supports 400 have different axial stiffnesses, thereby resulting in a substantially uniform outward deflection of the panel attachment nodes 342 when the panel 300 is subjected to an out-of-plane pressure load. For example, the first panel support 402 is formed of a first material having a first elastic modulus 422, the second panel support 404 is formed of a second material having a second elastic modulus 424, the third panel support 406 is formed of a third material having a third elastic modulus 426, the fourth panel support 408 is formed of a fourth material having a fourth elastic modulus 428, and the fifth panel support 410 is formed of a fifth material having a fifth elastic modulus 430. As a result, the axial stiffness of the fifth panel support 410 can be higher than the axial stiffness of the fourth panel support 408, the axial stiffness of the fourth panel support can be higher than the axial stiffness of the third panel support 406, and so on, similar to the above description of the embodiment of the present invention. Fig.17 In other embodiments not shown, the axial stiffness of at least two of the panel supports 400 can be varied by varying both the cross-sectional area A and the elastic modulus E (e.g., by varying the material of the panel support 400). A business study may be conducted to determine whether it is necessary to vary the cross-sectional area A, the elastic modulus E, or both to define a structurally effective configuration for the pressure vessel 200 that results in substantially uniform outward deflection of the panel attachment node 342 when the panel 300 is subjected to an out-of-plane pressure load. Variation of the axial stiffness of the panel support 400 can be more easily achieved by varying the cross-sectional area because the elastic modulus is a function of the material composition of a suitable material (e.g., a commonly available metallic material) that typically has a characteristic modulus that does not vary by several percent (e.g., aluminum has an elastic modulus that varies from approximately 10.0-10.5 million pounds per square inch). However, using panel supports 400 formed from different materials (eg, and therefore different elastic moduli) may provide the designer with additional flexibility in defining the cross-sectional area of ​​a set of panel supports 400 for a pressure vessel 200 .

[0080] In some embodiments, such as where the panel attachment nodes 342 are evenly spaced along the panel 300 (e.g., Figure 17 to Figure 18 ), the panel bracket 400 that couples the side bulkhead 206 to the panel 300 at the panel attachment node 342 located closest to the side bulkhead 206 may have a lower stiffness than the remaining panel brackets 400 that couple the side bulkhead 206 to the panel 300. For example, as described above with respect to Figure 17 to Figure 18As described for the arrangement of panel supports 400 with evenly spaced panel attachment nodes 342 in FIG. 1 , the axial stiffness of the first panel support 402 is lower than the axial stiffness of the second panel support 404, the third panel support 406, the fourth panel support 408, and the fifth panel support 410. The relatively low axial stiffness of the panel support 400 closest to each side bulkhead 206 may be a result of lower bending stresses at the panel side portions 326 and gradually higher bending stresses in the section of the panel span 324 between the panel side portions 326 and the panel center portion 330. However, for embodiments of the pressure vessel 200 in which the panel attachment nodes 342 are not evenly spaced, the axial stiffness of the panel support 400 may be different from the gradually increasing stiffness of the panel support 400 from the panel side portions 326 to the panel center portion 330 of each panel span 324.

[0081] Fig.19 An embodiment is shown in which the panel attachment nodes 342 are not evenly spaced. In the illustrated embodiment, the first panel support 402 and the third panel support 406 are omitted, and the pressure vessel 200 includes only the second panel support 404, the fourth panel support 408, and the fifth panel support 410. Fig.19 The first panel bracket 402 and the third panel bracket 406 are omitted and the spacing between the second panel bracket 404 and the fourth panel bracket 408 is increased, so the first panel bracket 402 and the third panel bracket 406 (for example, in Figure 17 to Figure 18 The out-of-plane pressure load carried by Fig.19 The increased axial load in the second panel support 404 determines the increased axial stiffness to achieve Fig.19 As described above, increased axial stiffness of the second panel bracket 404 may be achieved by increasing the cross-sectional area and / or by using a bracket material having a higher elastic modulus. Fig.19 The increased cross-sectional area of ​​the second panel support 404 relative to the cross-sectional areas of the fourth panel support 408 and the fifth panel support 410 is shown.

[0082] Reference Fig. 20 , shows a portion of an embodiment of a pressure vessel 200 having a plurality of panel brackets 400 coupling panels 300 to vessel ribs 230. Fig.21 yes Fig. 20 4. A cross-sectional view of one of the panel supports 400 of the panel supports 400. The panel 300 and / or at least one of the panel supports 400 may have a fail-safe configuration (i.e., configured to fail-safe) to prevent the panel 300 from being pressurized 470 ( Figure 4 ) during flight in the event of a failure of one of the panel supports 400. In the above-described embodiment of the center body 110 configured as a pressure vessel 200, the fail-safe construction of the panel support 400 can prevent panel failure during flight. In the present disclosure, failure of the panel 300 may be described as an overall buckling of the panel 300 due to excessive deflection. In this regard, if there is excessive deflection of the panel 300, the beam-column behavior of the panel 300 subjected to both in-plane and out-of-plane loads may be deteriorated. Fig. 20 If the fourth panel support 408 is ineffective in limiting outward deflection of its panel attachment node 342, the increased span between the third panel support 406 and the fifth panel support 410 may promote buckling under lower in-plane loads in the panel 300 rather than promoting buckling if the fourth panel support 408 is intact.

[0083] In one embodiment of a fail-safe configuration, at least one of the panel supports 400 may have an axial strength capability that prevents the panel 300 from failing if another of the panel supports 400 fails, e.g. Fig.19 Faulty bracket 456 is shown. The axial strength of panel bracket 400 can be described as the magnitude of the axial load at which the panel bracket 400 plastically yields or deforms and / or is no longer able to carry a certain amount of axial load when the panel bracket 400 is in its original state. Fig.19 As shown, the failed bracket 456 may crack or break to the extent that the failed bracket 456 cannot carry the axial load and may not be able to limit the outward deflection of the panel attachment node 342. In this regard, the failed bracket 456 may cause the panel attachment node 342 to locally deflect outward by an amount that causes the allowable bending stress of the panel 300 to be exceeded, and this may cause plastic deformation, yielding, or failure (e.g., buckling) of the panel 300.

[0084] Fig.21 Another embodiment of a fail-safe configuration is shown, wherein the panel support 400 has a residual axial strength capacity and a residual axial stiffness capacity configured to prevent the panel 300 from failing in the event of a failure of the same panel support 400. In this regard, the panel support 400 may be configured to continue to carry axial loads in the event of plastic deformation or rupture of a portion of the same panel support 400. For example, Fig.21The panel support 400 in the embodiment is constructed as a pair of C-shaped channels 458 arranged back-to-back and mechanically fastened to each other. Each of the C-shaped channels 458 can be configured so that if one of the C-shaped channels 458 fails (e.g., develops a fatigue crack), the remaining C-shaped channels 458 have axial strength and stiffness capabilities to prevent the panel 300 from failing (e.g., buckling), which would otherwise occur due to excessive localized outward deflection of the panel 300, similar to Fig.19 Although the above embodiments shown in Fig.21 The residual axial strength capacity and residual axial stiffness capacity of the panel support 400 may result in uneven outward deflection of the panel attachment node 342 , but the residual axial strength and stiffness capacity of the panel support 400 may prevent buckling of the panel 300 .

[0085] In another embodiment of a fail-safe configuration, the panel 300 may have a bending load capacity configured to prevent the panel 300 from bending in the event of a failed bracket 456 ( Fig.19 ) in the event of failure. In the present disclosure, the bending load capacity of the panel 300 may be described as the ability of the panel 300 to resist local bending to the extent that the panel 300 buckles. In one embodiment, the panel 300 may be constructed as a monocoque panel 314 ( Figure 12 to Figure 13 If one of the panel supports 400 fails (e.g., Fig.19 456 in the case of a failed bracket 456), the stringer 318 or the combination of the stringer 318 and the skin member 316 has a bending load capacity that allows the monocoque panel 314 to withstand the additional bending stress imposed on the monocoque panel 314 due to the failed bracket 456, thereby allowing the panel 300 to avoid buckling that would otherwise occur. The panel 300 can be provided in various alternative configurations (i.e., other than a monocoque panel) that have a bending load capacity that is configured to prevent the panel 300 from failing in the event of a failed bracket 456. For example, the panel 300 can be configured as a constant thickness plate 302 ( Figures 5 and 6 ), the panel 310 is constructed as an integral reinforcement ( Figure 7 ), is constructed as a sandwich panel 304 ( Fig. 9 ), or other structures.

[0086] Reference Fig. 22, shows a cross-sectional view of an embodiment of a pressure vessel 200 in which a substantially flat panel 300 is slightly curved. In the illustrated embodiment, the panel 300 can be described as a simply curved panel that is curved in one direction and has an arcuate shape. The panel 300 can have a degree of curvature such that the panel side portion 326 is not tangential to the corresponding bulkhead top portion 210. Fig. 22 In the embodiment shown in FIG. 1 , a side angle 329 between each side bulkhead 206 and a tangent line 328 to a panel side portion 326 may be between approximately 90 degrees and 120 degrees.

[0087] although Fig. 22 The panel 300 is shown as having a constant radius of curvature, but any of the panel configurations disclosed herein may have a variable radius of curvature along any of a number of directions. For example, in addition to the lateral direction 118 ( Figure 2 ), the panel (not shown) may also be curved along the longitudinal direction 120, and this may result in the panel 300 having curvature in two directions. In one embodiment, the panel 300 may be complexly curved along one direction or along two or more directions. Alternatively, the substantially flat panel 300 may be planar.

[0088] As described above, the panel 300 may have a variety of different structural configurations. For example, Figures 5 and 6 The panel 300 is shown as being constructed as a constant thickness plate 302. In this regard, such a constant thickness plate 302 may be a unitary body comprising any type of single material, including but not limited to a metallic material (e.g., aluminum), a fiber reinforced polymer matrix material (e.g., a carbon fiber reinforced epoxy composite), or any of a variety of other materials or combinations of materials. Figure 7 An embodiment of a panel 300 is shown that is configured as an integrally reinforced panel 310 having a plurality of integral plate ribs 312 (as shown by the dashed lines on one corner of the panel 300). The integral plate ribs 312 can be integrally formed in a desired geometric pattern, such as an integrally machined equal grid pattern, wherein the integral plate ribs 312 are oriented at 60 degrees to each other. However, the integral plate ribs 312 of the integrally reinforced panel 310 can be oriented at any angle (e.g., 90 degrees) relative to each other.

[0089] Briefly refer to Figure 12 to Figure 13 , shows an embodiment of a panel 300 configured as a monocoque panel 314 as described above, and having a skin member 316 and a plurality of stringers 318, which may be separately manufactured and coupled (e.g., mechanically fastened and / or adhesively bonded) to the skin member 316. The plurality of stringers 318 may be oriented along a common direction, such as along the transverse direction 118 ( Figure 7Alternatively, the plurality of longitudinal beams 318 may be oriented along two or more directions, such as along the transverse direction 118 and along the longitudinal direction 120 ( Figure 7 ).

[0090] Brief reference Fig. 9 , shows an embodiment of a panel 300 configured as a sandwich panel 304 having a pair of spaced apart skins 306 interconnected by a core 308. The skins 306 can be thin relative to the thickness of the core 308 and can be formed of composite and / or metallic materials. In the illustrated embodiment, the core 308 can have a constant thickness. However, in alternative configurations, the core 308 can have a non-constant thickness. The core 308 can be formed of a relatively lightweight material, such as foam, honeycomb, or any of a variety of other materials.

[0091] Reference Fig.23 , shows a top view of an embodiment of a pressure vessel 200 having container ribs 230 in different orientations. The pressure vessel 200 includes an opposing pair of side bulkheads 206 and an opposing pair of end bulkheads 208 interconnecting the side bulkheads 206. The side bulkheads 206 and the end bulkheads 208 define an outer perimeter of the pressure vessel 200. In the illustrated embodiment, the container ribs 230 include a first pair of container ribs 230 oriented parallel to each other and orthogonal to a second pair of container ribs 230. The side bulkheads 206, the end bulkheads 208, and the container ribs 230 divide the panel 300 into an orthogonal pattern of panel spans 324. However, in other embodiments of the pressure vessel 200, the container ribs 230 may not be parallel to each other and / or to the side bulkheads 206 and / or the end bulkheads 208.

[0092] Fig.24 An embodiment of a pressure vessel 200 is shown having side bulkheads 206 and end bulkheads 208 defining an outer perimeter of the pressure vessel 200, and having container ribs 230 oriented non-parallel to each other and / or non-parallel to the side bulkheads 206. The side bulkheads 206, end bulkheads 208, and container ribs 230 divide the panels 300 into a tessellated pattern of panel spans 324, which in the illustrated embodiment defines a hexagonal pattern. It will be appreciated that the side bulkheads 206, end bulkheads 208, and container ribs 230 may be arranged in any of a variety of orientations relative to each other to define any of a variety of shapes and patterns of panel spans 324. Fig.23 and Fig.24 The tessellation shown in FIG. 2 is uniform because the shapes defined by the side bulkheads 206, the end bulkheads 208, and the vessel ribs 230 have substantially the same size and / or shape. However, the pressure vessel 200 may have side bulkheads 206, the end bulkheads 208, and the vessel ribs 230 that result in any of a variety of tessellations of irregular size and / or irregular shape.

[0093] Figure 25 to Figure 27 is a cross-sectional view of an embodiment of a different panel configuration, the purpose of which is to illustrate the use of a panel bracket 400 ( Fig. 22 ) to support the substantially flat panel 300 of the pressure vessel 200 to achieve improved structural efficiency. Figure 25 to Figure 27 In each of the figures, the panel 300 is constructed as a sandwich panel 304 having opposing skins 306 separated by a core 308, as shown in FIG. Fig. 9 As shown and described above, the panel 300 is subjected to a uniform out-of-plane pressure load and is optimized such that the maximum skin stress (eg, in-plane tension) at any location in the panel 300 is 60 kilopounds per square inch (ksi).

[0094] Fig.25 is a cross-sectional view of a 2 inch thick panel supported by 6 strength brackets 348, which are sized for axial strength. In the present disclosure, the strength brackets 348 are sized for axial strength and are aligned with the panel brackets 400 ( Fig. 22 ), the panel supports are sized for axial stiffness such that outward deflection (e.g., vertical deflection) of the panel 300 is uniform. In this embodiment, sizing the strength supports 348 for axial strength can be described as sizing the supports to prevent the skin 306 from exceeding the maximum skin stress described above (i.e., 60 ksi), which may result in non-uniform outward deflection of the panel 300 under out-of-plane pressure loads. Fig.25 , the maximum deflection of the panel 300 at the center portion 330 of the panel is 2.606 inches.

[0095] Fig.26 is a cross-sectional view of a 2 inch thick panel supported by 12 strength braces 348. The maximum deflection at the center portion 330 of the panel is 2.585 inches, which is slightly less than Fig.26 The maximum deflection is 2.606 inches at the center portion 330 of the panel. Fig.25 The increase in the outward deflection of the panel attachment node 342 in Fig.26 The variation in the outward deflection of the panel attachment node 342 in FIG. 3 is reduced, showing that the deflected shape 344 of the panel 300 is strongly influenced by the size of the strength bracket 348 .

[0096] Fig. 27 is a cross-sectional view of a 4-inch thick panel supported by 12 strength braces 348. The maximum deflection at the center portion 330 of the panel is 2.376 inches, which is less than Fig.26 The maximum deflection is 3.017 inches at the center portion 330 of the panel. However, Fig. 27 The deflected shape 344 of the panel 300 in FIG. Fig.26 344 of the panel 300 in FIG. 3 , illustrating the relatively strong effect of the bracket size on the deflected shape 344 of the panel 300, and the relatively small effect of the panel thickness 340 on the deflected shape 344. In any of the embodiments of the pressure vessel 200 disclosed herein, the increase in structural efficiency provided by the panel bracket 400 can be greater for relatively long panel spans relative to the structural efficiency of a pressure vessel 200 having a shorter panel span.

[0097] Figures 28 to 30 There are different panel thicknesses 340( Fig. 9 ) of sandwich panel 304( Fig. 9 ) of the weight. These graphs are presented for the purpose of illustrating how the panel support 400 ( Fig. 22 ) to support the pressure vessel 200( Fig. 22 ) of a substantially flat panel 300 ( Fig. 22 Each sandwich panel 304 is subjected to a uniform out-of-plane pressure load and is optimized to have a maximum skin stress of 60 ksi.

[0098] Fig.28 34 is a graph of skin thickness 341 versus spanwise position 334 for two (2) sandwich panels 304 having different faceplate thicknesses 340. One of the sandwich panels 304 has a faceplate thickness 340 of 1 inch, while the other sandwich panel 304 has a faceplate thickness 340 of 6 inches. Each sandwich panel 304 is supported by 10 strength braces 348 ( Figure 25 to Figure 27 The variation in skin thickness 341 across the width (eg, span) of the sandwich panel 304 is a result of the above-described optimization, wherein the maximum skin stress (eg, in-plane tension) at any location in the sandwich panel 304 is 60 ksi. Fig.28 The graph shows that the skin thickness 341 of the 1 inch thick sandwich panel 304 is generally (i.e., at most spanwise locations) less than the skin thickness 341 of the 6 inch thick sandwich panel 304. This is because the 6 inch thick sandwich panel 304 carries a larger portion of the out-of-plane pressure load in the panel bending than the portion of the panel bending carried by the 1 inch thick sandwich panel 304.

[0099] Fig.29 is a graph of skin thickness 341 versus spanwise position 334 for three (3) sandwich panels 304 comprising Fig.25 The two (2) sandwich panels 304 shown in FIG. 1 and also include a 6 inch thick sandwich panel 304 without strength braces. Fig.29The graph of shows that the skin thickness 341 of the supported panel is significantly less than the skin thickness 341 of the unsupported panel, thereby illustrating the weight reduction achieved by supporting the sandwich panel 304 with the strength braces 348 . Fig.30 is a graph of total weight per unit area relative to panel thickness 340 for several panel configurations, including a sandwich panel 304 without strength supports 348, a sandwich panel 304 supported by two (2) strength supports 348, a sandwich panel 304 supported by four (4) strength supports 348, and a sandwich panel 304 supported by 10 strength supports 348. Fig.30 The total weight in is the sum of the weight of the panel 300 plus the weight of the panel support 400. As shown in the graph, an increase in the total number of strength supports 348 supporting the panel 300 generally results in a decrease in the weight per unit area of ​​the panel 300, thereby illustrating the weight reduction achieved by using the panel support 400 to support the panel 300.

[0100] Figure 31 to Figure 32 Different panel thickness 340( Fig. 9 ) and the sandwich panels 304 are supported by different numbers of panel supports 400. However, as indicated above, the presently disclosed pressure vessels 200 with panel supports 400 may be implemented with panels 300 having any of a variety of different panel configurations and are not limited to sandwich panels 304. As described above, the panel supports 400 are configured for axial stiffness such that each sandwich panel 304 experiences a substantially uniform outward deflection at the panel attachment node 342 when the sandwich panels 304 are subjected to out-of-plane pressure loads. Fig.31 The sandwich panel 304 is shown supported by four panel supports 400 adjusted for axial stiffness. Although the panel attachment nodes 342 deflect outwardly by a substantially uniform amount, the panel 300 exhibits panel bending in the panel segments 332 closest to the panel side portions 326 . Fig.32 A sandwich panel 304 is shown having a Fig.31 The same panel thickness 340 in the embodiment of the present invention and supported by 12 panel supports 400 adjusted for axial stiffness in such a manner as to result in substantially uniform outward deflection at the panel attachment nodes 342. Fig.32 Shows relative to Fig.31 The amount of outward deflection between the panel attachment nodes 342, the reduced amount of outward deflection between the panel attachment nodes 342, and the effect of changing the number of brackets on reducing the magnitude of the outward deflection of the panel 300 between the panel attachment nodes 342 are shown.

[0101] Fig.33is a graph of total panel weight versus panel thickness 340 for several panel configurations in which the sandwich panel 304 is subjected to a uniform out-of-plane pressure load as described above. The panel configurations include a 1 inch thick sandwich panel 304 supported by two (2) strength brackets 348 sized for axial strength, a sandwich panel 304 supported by two (2) panel brackets 400 sized for axial stiffness, a sandwich panel 304 supported by four (4) strength brackets 348, a sandwich panel 304 supported by four (4) panel brackets 400 sized for axial stiffness, a sandwich panel 304 supported by twelve panel brackets 400 sized for axial stiffness, and a sandwich panel 304 supported by twelve panel brackets 400 sized for axial stiffness. Fig.33 The graph of 400 shows that increasing the number of panel brackets 400 generally reduces the total panel weight, which can be described as the combined weight of the sandwich panel 304 and the panel brackets 400. Although the graph shows a small weight increase (i.e., adjusted for axial stiffness) for a sandwich panel 304 supported by a panel bracket 400 compared to the reduced weight of a corresponding sandwich panel 304 supported by a strength bracket 348, the small weight increase is due to the larger size (e.g., greater axial stiffness) and corresponding increased weight of the bracket (e.g., panel bracket 400 or strength bracket 348) connected to the panel attachment node 342 at the panel center portion 330.

[0102] In designing the pressure vessel 200, in addition to sizing the panel brackets 400 for axial stiffness to achieve substantially uniform outward deflection at the panel attachment nodes 342 when the panels 300 are under out-of-plane pressure loads, it is also necessary to analyze the buckling of the panels 300 under compressive loads. For example, a pressure vessel 200 configured as the payload bay 108 of the hybrid wing body aircraft 100 described above may be subjected to flight loads that place the panels 300 in in-plane tension, compression, and / or shear, and this may cause the panels 300 to fail or buckle. If the analysis indicates that the panels 300 will buckle when subjected to in-plane loads with or without out-of-plane pressure loads, the panels 300 must be sized to avoid such failure. The resized panels may have increased bending stiffness, and this may require resizing the panel brackets 400 for axial stiffness so that they are stiff enough to prevent buckling of the panels 300. In this regard, the panel mounts 400 must each be configured to have an axial stiffness that results in substantially uniform outward deflection of the panel attachment nodes 342 when the panel mounts 400 are resized.

[0103] As an example of the above resizing process, Fig.34342 . FIG. 344 is a cross-sectional view of an embodiment of a sandwich panel 304 supported by twelve panel supports 400 and subjected to an out-of-plane pressure load for which the panel supports 400 were initially configured to have an axial stiffness that results in uniform outward deflection of the panel attachment nodes 342. After the panel supports 400 are configured, the panel 300 is subjected to an in-plane buckling load (e.g., a compressive load) while being subjected to the out-of-plane pressure load. Due to the in-plane buckling load, the amount of outward deflection of the panel 300 at the panel attachment node 342 may exhibit very little variation. As described above, the panel supports 400 may be reconfigured to have an axial stiffness that results in uniform outward deflection of the panel attachment nodes 342 by changing the cross-sectional area and / or elastic modulus of one or more of the panel supports 400.

[0104] Fig.35 is a flow chart of operations included in a method 500 of loading a pressure vessel 200. The method 500 includes a step 502 of internally pressurizing a pressure vessel 200, which, as described above, is at least partially enclosed by a panel 300 having at least one panel span 324 extending between a pair of side bulkheads 206, each side bulkhead having a bulkhead top portion 210 non-contactingly adjacent to the panel 300. In an embodiment of an aircraft 100, the pressure vessel 200 includes a passenger cabin 112 and / or a cargo bay 114, and the panel 300 may serve as an aerodynamic surface 116 of the aircraft. In such an arrangement, the method may include subjecting the panel 300 to flight loads during pressurization of the passenger cabin 112 and / or the cargo bay 114.

[0105] Step 504 of method 500 includes generating an out-of-plane pressure load on panel 300 in response to internally pressurizing pressure vessel 200. The pressure load is evenly distributed on panel 300. In embodiments of a passenger cabin 112 and / or cargo bay 114 of an aircraft, the out-of-plane pressure load on panel 300 may be achieved by pumping conditioned air into passenger cabin 112 and / or cargo bay 114.

[0106] Step 506 of method 500 includes transferring out-of-plane pressure loads from the panels 300 to the side bulkheads 206 using a plurality of panel supports 400 that couple the side bulkheads 206 to the panels 300 at a plurality of panel attachment nodes 342 distributed along the panel spans 324. In some embodiments, the method may include transferring out-of-plane pressure loads from the panels 300 to at least one vessel rib 230 using a plurality of panel supports 400 that couple the rib top portion 232 to a plurality of panel attachment nodes 342 distributed along at least one panel span 324. As shown, one or more vessel ribs 230 are located between the side bulkheads 206 and adjacent to the panels 300 without contact. Method 500 may further include transferring out-of-plane pressure loads from the panels 300 to one or more end bulkheads 208 located on at least one of the opposing ends of the pressure vessel 200 using the plurality of panel supports 400.

[0107] In some embodiments (e.g., Figure 17 to Figure 18 ), the step 506 of transferring the out-of-plane pressure load from the panel 300 to the side bulkhead 206 may include transferring the out-of-plane pressure load using at least one panel bracket 400, the at least one panel bracket having a cross-sectional area and a corresponding axial stiffness different from the cross-sectional area and the corresponding axial stiffness of one or more of the remaining panel brackets 400 coupling the pair of side bulkheads 206 to the panel 300. Alternatively or additionally, the step 506 may include transferring the out-of-plane pressure load using at least one panel bracket 400, the at least one panel bracket having an elastic modulus and a corresponding axial stiffness different from the elastic modulus and the corresponding axial stiffness of one or more of the remaining panel brackets 400 coupling the pair of side bulkheads 206 to the panel 300.

[0108] The step 506 of transferring the out-of-plane pressure load from the panel 300 to the side bulkheads 206 may also include transferring the out-of-plane pressure load to at least one of the side bulkheads 206 using a panel bracket 400 connected to the panel attachment node 342 closest to the side bulkhead 206. As described above, due to the reduced magnitude of the bending moment on the panel 300 at the panel attachment node 342 closest to the side bulkhead 206, such a panel bracket 400 may be configured to have a lower axial stiffness than the remaining panel brackets 400. Step 506 may include using a pin connection 452 ( Fig. 9 ) allows the panel 300 to rotate relative to the panel support 400 at the panel attachment node 342. Alternatively, step 506 may include using a rigid connector 454 ( Figure 12 to Figure 13) prevents the panel 300 from rotating relative to the panel support 400 at the panel attachment node 342. Depending on the type of load and the amount of outward deflection of the panel 300, it may be desirable for some of the panel supports 400 to be coupled to the panel attachment nodes 342 using pin connections 452 while other panel supports 400 are coupled to other panel attachment nodes 342 using rigid connections 454.

[0109] Step 506 may also include transferring the out-of-plane pressure load from the panel 300 to the common bracket-bulkhead attachment location 218 on at least one of the side bulkheads 206 via one or more of the plurality of panel brackets 400. For example, Figures 8 to 9 The panel bracket 400 is shown attached to the bulkhead top portion 210 of the side bulkhead 206 at a common bracket-bulkhead attachment location 218. Similarly, the panel bracket 400 is attached to the rib top portion 232 of the container rib 230 at a common bracket-rib attachment location 240. However, in embodiments not shown, the panel bracket 400 may be attached to the side bulkhead 206 at vertically spaced locations along the side bulkhead 206. Likewise, the panel bracket 400 may be attached to the container rib 230 at vertically spaced locations along the container rib 230.

[0110] In some embodiments, the pressure vessel 200 may have a fail-safe configuration such that in the event of a failed support 456 during internal pressurization 470 of the pressure vessel 200, the method 500 includes carrying a higher axial load in one or more remaining panel supports 400 of the plurality of panel supports 400 than the axial load carried by any of the plurality of panel supports 400 if no panel supports failed. The fail-safe configuration may prevent failure of the panel 300 that would otherwise occur due to bending deflections that cause the panel to bend, wherein an allowable bending stress of the panel 300 is exceeded. For example, Fig.19 As shown, the panel 300 may be subjected to excessive bending loads at the panel attachment node 342 coupled to the failed bracket 456. In this case, the remaining panel brackets 400 may carry the axial loads that would otherwise be carried by the failed bracket 456, and failure of the panel 300 may thereby be prevented.

[0111] In another embodiment of a fail-safe configuration, method 500 may include using the residual strength capacity of failure bracket 456 to carry an axial load that can prevent failure of panel 300. For example, Fig.21As shown, the failure bracket 456 can be configured as a pair of back-to-back C-shaped channels 458, either of which has a residual axial strength capacity and a residual axial stiffness capacity that prevents failure of the panel 300 in the event that the remaining C-shaped channel 458 develops cracks (e.g., fatigue cracks) and cannot carry its designed axial load. In yet another embodiment of a fail-safe configuration, the method may include carrying a higher bending load in the panel 300 than the bending load carried by the panel 300 if none of the panel brackets 450 fails, to prevent failure of the panel 300 that would otherwise occur due to bending deflections of the panel 300 that result in exceeding allowable bending stresses of the panel 300. As described above, the bending load capacity of the panel 300 can be described as the resistance of the panel 300 to overall buckling of the panel 300.

[0112] Step 508 of method 500 includes limiting the outward deflection of panel attachment nodes 342 to substantially equal deflection amounts 346 (e.g., within 10% or less of each other) when the pressure vessel 200 is internally pressurized based on different axial stiffnesses among at least two of the panel supports 400 using a plurality of panel supports 400. Advantageously, limiting the outward deflection of the panels 300 to substantially equal amounts may reduce or prevent changes in the profile of the panels 300 during internal pressurization 470 of the pressure vessel 200. Additionally, using panel supports 400 to couple the panels 300 to the side bulkheads 206 rather than attaching the panels 300 directly to the side bulkheads 206 and vessel ribs 230 (if included) may result in a decoupling of out-of-plane pressure loads (e.g., due to internal pressurization 470) and in-plane loads (e.g., compressive, tensile, and / or shear loads) on the panels 300. In embodiments of blended wing body aircraft 100 , such in-plane loads may be flight loads due to wing bending, or aerodynamic loads on center body 110 , or other factors.

[0113] The method 500 may include sealing the bulkhead top portion 210 of at least one of the side bulkheads 206 to the panel 300. Sealing the panel 300 to the side bulkhead 206 may be performed using a pressure suppression mechanism 472 that is configured to prevent leakage between the bulkhead top portion 210 and the panel 300, thereby allowing the interior of the pressure vessel 200 to be pressurized 470. In one embodiment described above, the pressure suppression mechanism 472 may include a pressure diaphragm 474 of a material (e.g., a sheet of rubber, silicone, etc.) extending between the panel 300 and the side bulkhead 206, such as Fig.13 As shown. Fig.14In another embodiment shown, the pressure suppression mechanism 472 may include a block 476 of elastomeric material (e.g., closed cell foam) compressed and mounted between the bulkhead top portion 210 and the panel 300. Figure 15 to Figure 16 In yet another embodiment shown in FIG. 4 , the pressure suppression mechanism 472 may include a plate seal assembly 478 having a first plate 480, a second plate 482, and a sealing member 484, which may be a sealing strip 486 captured between the first plate 480 and the second plate 482. In another embodiment, the sealing member 484 may be a ball seal 490, such as an O-ring seal ( Fig.16 ).

[0114] Fig.36 is a flow chart of operations included in a method 600 of manufacturing a pressure vessel 200. The method includes Figure 4 The step 602 of positioning a pair of side bulkheads 206 in spaced relation to each other is shown. As described above, the side bulkheads 206 each have a bulkhead top portion 210.

[0115] The method 600 further includes step 604 of positioning the substantially planar panel 300 non-contactingly adjacent to the bulkhead top portion 210 such that a panel-bulkhead gap 214 exists between the panel 300 and each of the side bulkheads 206 and such that at least one panel span 324 extends between the pair of side bulkheads 206, as shown in FIG. Figure 4 As described above, the panels 300 and the side bulkheads 206 collectively form at least a portion of the structural assembly 198 that encloses the pressure vessel 200. In some embodiments, the step 604 of positioning a pair of side bulkheads 206 in a spaced relationship with each other may include orienting the side bulkheads 206 to be parallel to each other (e.g., Figure 2 ). However, in an embodiment not shown, the side partition walls 206 may not be parallel to each other.

[0116] In some embodiments, the pressure vessel 200 may be a hybrid wing body aircraft 100 as described above (e.g., Figures 1 to 3 ) of the center body 110 and may be associated with the cabin 112 and / or cargo bay 114. The panel 300 may be an upper skin panel of the center body 110 and may define an aerodynamic surface 116 of the center body 110. Additionally, the upper skin panel may be subject to flight loads during pressurization of the cabin 112 and / or cargo bay 114 (e.g., due to wing bending, aerodynamic loads on the center body 110, or other loads).

[0117] The method 600 also includes a step 606 of coupling each of the side bulkheads 206 to the panel 300 at a plurality of panel attachment nodes 342 distributed along the panel span 324 using a plurality of panel supports 400. As described above, at least two of the panel supports 400 have different axial stiffnesses that cause or limit the panel attachment nodes 342 to deflect outwardly by substantially equal amounts 346 when the panel 300 is subjected to an out-of-plane pressure load during internal pressurization 470 of the pressure vessel 200. The method may also include coupling at least one end bulkhead 208 ( Figure 2 ) is connected to panel 300 as described above.

[0118] The method 600 may also include positioning at least one container rib 230 between the pair of side bulkheads 206. For example, Figure 4 Two (2) container ribs 230 are shown positioned between the pair of side bulkheads 206, but the pressure vessel 200 may include any number of container ribs 230. The container ribs 230 are configured such that the panel 300 is adjacent to the rib top portion 232 of each container rib 230 without contact, and a panel-rib gap 236 is created between the panel 300 and each container rib 230. The method may further include coupling each container rib 230 to the panel 300 using a plurality of panel brackets 400. For example, the plurality of panel brackets 400 may extend from the rib top portion 232 to a corresponding plurality of panel attachment nodes 342 distributed along the panel 300, as shown in FIG. Figure 4 shown.

[0119] The step 606 of coupling each side bulkhead 206 to the panel 300 may include coupling the side bulkhead 206 to the panel 300 using a plurality of panel brackets 400, wherein the cross-sectional area and / or elastic modulus of at least two of the panel brackets are different from the cross-sectional area and / or elastic modulus of the remaining panel brackets 400, respectively. As described above, the axial stiffness of the panel bracket 400 may be changed by changing the cross-sectional area and / or elastic modulus of the panel bracket 400. The elastic modulus of the panel bracket 400 may be changed by changing the material forming the panel bracket 400. In some embodiments, the step 606 of coupling each of the side bulkheads 206 to the panel 300 at a plurality of panel attachment nodes 342 may include coupling a panel attachment node 342 that is closest to one of the side bulkheads 206 using a panel bracket 400 that has a lower axial stiffness than the remaining panel brackets 400 coupling the side bulkhead 206 to the panel 300. For example, at Figure 17 to Figure 18, the first panel bracket 402 may have a lower axial stiffness than the second panel bracket 404 to the fifth panel bracket 410. Due to the relatively low bending moment in the panel 300 at the panel attachment node 342 to which the first panel bracket 402 is coupled, the first panel bracket 402 may be configured to have a relatively low axial stiffness.

[0120] Step 606 of coupling the side bulkhead 206 to the panel 300 at the plurality of panel attachment nodes 342 may include using pin connections 452 (e.g., Fig. 9 ) or a rigid connector 454 (e.g., Figure 12 to Figure 13 ) connect each of the panel brackets 400 to the panel attachment node 342. As described above, the pin connector 452 allows the panel 300 to rotate relative to the panel bracket 400 at the panel attachment node 342, while the rigid connector 454 prevents the panel 300 from rotating relative to the panel bracket 400 at the panel attachment node 342. The pin connector 452 or the rigid connector 454 can also be used to attach the panel bracket 400 to the side bulkhead 206 at the bracket-bulkhead attachment location 218, or to attach the panel bracket to the container rib 230 at the bracket-rib attachment location 240, as described above. Figures 8 to 11 shown.

[0121] Step 606 of coupling the side bulkhead 206 to the panel 300 at the panel attachment node 342 may include attaching at least two of the panel brackets 400 to the common bracket-bulkhead attachment location 218 ( Fig.13 ) or a common bracket-rib attachment location 240 (e.g. Fig. 9 ). Additionally, one or more of the panel brackets 400 may be attached to the side bulkhead 206 or container rib 230 using pin connectors 452 or rigid connectors 454.

[0122] In some embodiments, step 606 of coupling side bulkhead 206 to panel 300 may include coupling side bulkhead 206 to panel 300 using at least one panel bracket 400 having an axial strength capability to prevent failure (e.g., buckling) of panel 300 in the event of failure of another of panel brackets 400. Failure bracket 456 ( Fig.19) may be described as being unable to carry an axial load. As described above, a panel failure may include buckling of the panel 300 due to excessive deflection of the panel attachment node 342 of the panel 300 proximate the failed bracket 456. In another embodiment, step 606 may include coupling the side bulkhead 206 to the panel 300 using at least one panel bracket 400 having a residual axial strength capacity and a residual axial stiffness capacity that prevents failure of the panel 300 in the event of a failure of the same panel bracket 400. For example, the panel bracket 400 may be constructed as a pair of back-to-back bracket members, such as back-to-back C-shaped channels 458. If a fatigue crack develops in one of the C-shaped channels 458, the remaining C-shaped channels 458 may have a residual axial strength capacity and a residual axial stiffness capacity that prevents failure of the panel 300. Although Fig.21 The panel support 400 is shown as a back-to-back C-shaped channel 458, but the panel support 400 can be configured as any of a variety of configurations having residual axial strength capacity and residual axial stiffness capacity that prevent failure of the panel 300 in the event of failure of the same panel support 400.

[0123] In yet another embodiment of a fail-safe configuration of the pressure vessel 200, step 606 may include coupling the side bulkhead 206 to a panel 300 having a bending load capacity value that is higher than the bending load carried by the panel 300 when none of the panel supports 400 fails. In this regard, if one of the panel supports 400 fails, the panel 300 may have a bending load carrying capacity that allows the panel 300 to withstand the additional bending loads imposed on the panel 300 due to the failed support 456. For any of the above-described fail-safe configurations, the pressure vessel 200 may include a structural health monitoring system (not shown) configured to monitor and detect failure of any of the panel supports 400. In the event that a failure of one of the panel supports 400 is detected, the structural health monitoring system may allow operation of the pressure vessel 200 to be limited in a manner that reduces the magnitude of the external loads on the pressure vessel 200 to prevent failure of the panel 300. In an aircraft 100 (e.g., a pressure vessel 200) having a pressurized cabin 112 (e.g., Figures 1 to 3), the structural health monitoring system may include a system of sensors (e.g., strain gauges, accelerometers, electrical continuity sensors) mounted on each of the panel supports 400 for detecting failure of the panel supports 400. Upon identification of a failure of one or more of the panel supports 400, the structural health monitoring system may cause the aircraft 100 to be operated in a manner that reduces external loads (e.g., in-flight loads) on the aircraft 100 until the aircraft 100 is landed and the panel supports 400 are repaired or replaced.

[0124] The method 600 may also include sealing the panel 300 to at least one of the side bulkheads 206 using a pressure suppression mechanism 472. For example, the pressure suppression mechanism 472 may extend between the panel 300 and the bulkhead top portion 210 of the side bulkhead 206. The pressure suppression mechanism 472 may prevent leakage between the side bulkhead 206 and the panel 300, thereby allowing the interior of the pressure vessel 200 to be pressurized 470. The pressure suppression mechanism 472 may be provided in a variety of configurations, including one or more of the configurations described above.

[0125] Furthermore, the present disclosure includes embodiments according to the following clauses:

[0126] 1. A pressure vessel, comprising:

[0127] at least one pair of side bulkheads, the at least one pair of side bulkheads being spaced apart from each other and each having a bulkhead top portion;

[0128] at least one substantially planar panel having at least one panel span extending between the pair of side bulkheads and non-contactingly adjacent top portions of the bulkheads, the panel and the side bulkheads collectively forming at least a portion of a structural assembly enclosing the pressure vessel; and

[0129] and a first plurality of panel supports coupling each of the side bulkheads to the panel at a corresponding first plurality of panel attachment nodes distributed along the span of the panel, wherein at least two of the panel supports in the first plurality of panel supports have different axial stiffnesses, the different axial stiffnesses being configured to cause the first plurality of panel attachment nodes to deflect outwardly by substantially equal amounts when the panel is subjected to out-of-plane pressure loads during internal pressurization of the pressure vessel.

[0130] 2. The pressure vessel according to clause 1, further comprising:

[0131] at least one container rib located between the pair of side bulkheads and having a rib top portion non-contactingly adjacent the panel; and

[0132] The at least one container rib is coupled to the panel using a second plurality of panel standoffs extending from the rib top portion to a second plurality of panel attachment nodes distributed along the panel.

[0133] 3. The pressure vessel of clause 1, wherein at least one of the first plurality of panel supports coupling one of the side bulkheads to the panel has at least one of the following configurations:

[0134] a cross-sectional area and corresponding axial stiffness that is different from the cross-sectional area and corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets coupling the pair of side bulkheads to the panel; and

[0135] An elastic modulus and a corresponding axial stiffness, wherein the elastic modulus and the corresponding axial stiffness are different from the elastic modulus and the corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets connecting the pair of side bulkheads to the panel.

[0136] 4. A pressure vessel according to clause 1, wherein:

[0137] A panel bracket of the first plurality of panel brackets coupling one of the side bulkheads to the panel at a panel attachment node of the first plurality of panel attachment nodes that is closest to one of the side bulkheads has a lower stiffness than the remaining first plurality of panel brackets coupling one of the side bulkheads to the panel.

[0138] 5. A pressure vessel according to clause 1, wherein:

[0139] The first plurality of panel attachment nodes are non-uniformly spaced along the at least one panel span.

[0140] 6. A pressure vessel according to any one of clauses 1 to 5, wherein:

[0141] At least two panel brackets of the first plurality of panel brackets extending from one of the at least one pair of side bulkheads are attached to the bulkhead top portion at a single bracket-bulkhead attachment location.

[0142] 7. The pressure vessel according to any one of clauses 1 to 5, further comprising:

[0143] At least one pressure suppression mechanism is configured to seal the panel to at least one of the pair of side bulkheads for pressurizing the interior of the pressure vessel.

[0144] 8. A pressure vessel according to any one of clauses 1 to 5, wherein:

[0145] At least one of the panel and the first plurality of panel supports is configured for fail-safe to prevent failure of the panel in the event of failure of one of the first plurality of panel supports.

[0146] 9. The pressure vessel of clause 8, wherein the fail-safe configuration comprises at least one of:

[0147] at least one of the first plurality of panel supports having an axial strength capability to prevent failure of the panel in the event of failure of another of the first plurality of panel supports;

[0148] at least one of the first plurality of panel supports has a residual axial strength capacity and a residual axial stiffness capacity to prevent failure of the panel in the event of failure of the at least one of the first plurality of panel supports; and

[0149] The panel has a bending load capacity to prevent failure of the panel if one of the first plurality of panel supports fails.

[0150] 10. A pressure vessel according to any one of clauses 1 to 5, wherein:

[0151] The pressure vessel comprises at least one of a passenger cabin and a cargo cabin of an aircraft; and

[0152] The panels include skin panels defining an aerodynamic surface of the aircraft and configured to withstand flight loads during pressurization of at least one of the passenger cabin and the cargo bay.

[0153] 11. A method of loading a pressure vessel, the method comprising:

[0154] internally pressurizing the pressure vessel at least partially surrounded by panels having at least one panel span extending between a pair of side bulkheads, each side bulkhead having a bulkhead top portion non-contactingly adjacent the panels;

[0155] generating an out-of-plane pressure load on the panel in response to internally pressurizing the pressure vessel;

[0156] transferring the out-of-plane pressure load from the panel to the pair of side bulkheads using a first plurality of panel brackets coupling respective ones of the side bulkheads to the panel at a first plurality of panel attachment nodes distributed along the at least one panel span; and

[0157] When the pressure vessel is internally pressurized, outward deflection of the first plurality of panel attachment nodes is limited to substantially equal deflection amounts, the outward deflection being limited by the first plurality of panel supports, the first plurality of panel supports having different axial stiffnesses among at least two of the panel supports in the first plurality of panel supports.

[0158] 12. The method according to clause 11, further comprising:

[0159] The out-of-plane pressure load is transferred from the panel to at least one container rib using a second plurality of panel supports coupling a rib top portion to a second plurality of panel attachment nodes distributed along the span of the at least one panel, the at least one container rib being located between the pair of side bulkheads and non-contactingly adjacent the panel.

[0160] 13. The method of clause 11, wherein transferring the out-of-plane pressure load from the face sheet to the pair of side bulkheads comprises:

[0161] The out-of-plane pressure load is transferred using at least one panel support of the first plurality of panel supports, the at least one panel support having at least one of the following configurations:

[0162] a cross-sectional area and corresponding axial stiffness that is different from the cross-sectional area and corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets coupling the pair of side bulkheads to the panel; and

[0163] An elastic modulus and a corresponding axial stiffness, wherein the elastic modulus and the corresponding axial stiffness are different from the elastic modulus and the corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets connecting the pair of side bulkheads to the panel.

[0164] 14. The method according to any one of clauses 11 to 13, wherein, in case of a faulty bracket among the first plurality of panel brackets, the method further comprises at least one of the following steps:

[0165] carrying in one or more remaining panel supports of the first plurality of panel supports a higher axial load than would be carried by any panel support of the first plurality of panel supports in the absence of failure to prevent failure of the panel due to buckling;

[0166] carrying an axial load in the failure bracket capable of preventing failure of the panel; and

[0167] A bending load higher than a bending load carried by the panel when none of the first plurality of panel supports fails is carried in the panel to prevent failure of the panel due to buckling.

[0168] 15. The method of any one of clauses 11 to 13, wherein the pressure vessel comprises at least one of a passenger cabin and a cargo hold of an aircraft, the panel comprises an aerodynamic surface, the method further comprising:

[0169] The panel is used to withstand flight loads imposed on the panel during pressurization of at least one of the passenger cabin and the cargo cabin.

[0170] 16. A method of manufacturing a pressure vessel, the method comprising:

[0171] positioning a pair of side bulkheads in spaced relationship with one another, the pair of side bulkheads each having a bulkhead top portion;

[0172] positioning a substantially planar panel non-contactingly adjacent to the bulkhead top portion of each of the pair of side bulkheads such that at least one panel span extends between the pair of side bulkheads, the panel and the pair of side bulkheads collectively forming at least a portion of a structural assembly enclosing the pressure vessel; and

[0173] Each of the side bulkheads is coupled to the panel at a corresponding first plurality of panel attachment nodes distributed along the span of the panel using a first plurality of panel supports, at least two of the panel supports in the first plurality of panel supports having different axial stiffnesses, the different axial stiffnesses causing the first plurality of panel attachment nodes to deflect outwardly by substantially equal amounts when the panel is subjected to out-of-plane pressure loads during internal pressurization of the pressure vessel.

[0174] 17. The method according to clause 16, further comprising:

[0175] positioning at least one container rib between the pair of side bulkheads such that the panel is non-contactingly adjacent a top portion of the rib; and

[0176] The at least one container rib is coupled to the panel using a second plurality of panel brackets extending from a top portion of the rib to a second plurality of panel attachment nodes distributed along the panel.

[0177] 18. The method of clause 16, wherein coupling each of the side bulkheads to the panel at the first plurality of panel attachment nodes comprises:

[0178] Each of the side bulkheads is coupled to the first plurality of panel attachment nodes, wherein the first plurality of panel attachment nodes are non-uniformly spaced along the panel span.

[0179] 19. The method of any of clauses 16 to 18, wherein coupling each of the side bulkheads to the panel at the first plurality of panel attachment nodes comprises:

[0180] The side bulkhead is coupled to the panel using the first plurality of panel brackets, the first plurality of panel brackets having at least one of the following configurations:

[0181] a cross-sectional area and corresponding axial stiffness that is different from the cross-sectional area and corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets coupling the panel to the pair of side bulkheads; and

[0182] An elastic modulus and corresponding axial stiffness, wherein the elastic modulus and the corresponding axial stiffness are different from the elastic modulus and the corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets connecting the panel to the pair of side bulkheads.

[0183] 20. The method of any of clauses 16 to 18, wherein coupling each of the side bulkheads to the panel at the first plurality of panel attachment nodes comprises at least one of the following steps:

[0184] coupling the pair of side bulkheads to the panel using one or more panel brackets of the first plurality of panel brackets, the one or more panel brackets having an axial strength capable of preventing failure of the panel in the event of a failed panel bracket of the first plurality of panel brackets;

[0185] coupling the pair of side bulkheads to the panel using at least one panel support of the first plurality of panel supports, the at least one panel support having a residual axial strength capacity and a residual axial stiffness capacity to prevent failure of the panel in the event of a failure of the same panel support; and

[0186] The pair of side bulkheads are coupled to the panel, the panel having a bending load capacity value higher than a bending load carried by the panel when none of the panel supports of the first plurality of panel supports fails.

[0187] Additional modifications and improvements of the present disclosure are obvious to those skilled in the art. Therefore, the particular combination of components described and shown herein is intended to represent only certain embodiments of the present disclosure and is not intended to be used as a limitation of alternative embodiments or devices within the spirit and scope of the present disclosure.

Claims

1. A pressure vessel (200), comprising: at least one pair of side bulkheads (206) spaced apart from each other and each having a bulkhead top portion (210); at least one substantially planar panel (300) having at least one panel span (324) extending between the pair of side bulkheads and non-contactingly adjacent top portions of the bulkheads, the panel and the side bulkheads collectively forming at least a portion of a structural assembly (198) enclosing the pressure vessel; as well as a first plurality of panel supports (400) coupling each of the side bulkheads to the panel at a corresponding first plurality of panel attachment nodes (342) distributed along the span of the panel, at least two of the panel supports in the first plurality of panel supports having different axial stiffnesses, the different axial stiffnesses being configured to cause the first plurality of panel attachment nodes to deflect outwardly by substantially equal amounts (346) when the panel is subjected to an out-of-plane pressure load during internal pressurization (470) of the pressure vessel.

2. The pressure vessel (200) according to claim 1, further comprising: at least one container rib (230) located between the pair of side bulkheads (206) and having a rib top portion (232) non-contactingly adjacent the panel (300); and The at least one container rib is coupled to the panel using a second plurality of panel brackets (400) extending from the rib top portion to a second plurality of panel attachment nodes (342) distributed along the panel.

3. The pressure vessel (200) according to claim 1, wherein: At least one panel bracket (400) of the first plurality of panel brackets coupling one of the side bulkheads (206) to the panel (300) has at least one of the following configurations: a cross-sectional area and corresponding axial stiffness that differs from the cross-sectional area and corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets coupling the pair of side bulkheads to the panel; as well as An elastic modulus and corresponding axial stiffness that are different from the elastic modulus and corresponding axial stiffness of one or more panel brackets in the first plurality of panel brackets that couple the pair of side bulkheads to the panel.

4. The pressure vessel (200) according to claim 1, wherein: A panel bracket of the first plurality of panel brackets (400) that couples the one of the side bulkheads (206) to the panel (300) at a panel attachment node that is closest to one of the side bulkheads in the first plurality of panel attachment nodes (342) has a lower stiffness than the remaining first plurality of panel brackets that couple the one of the side bulkheads to the panel.

5. The pressure vessel (200) according to claim 1, wherein: The first plurality of panel attachment nodes (342) are non-uniformly spaced along the at least one panel span (324).

6. The pressure vessel (200) according to any one of claims 1 to 5, wherein: At least two panel brackets of the first plurality of panel brackets (400) extending from one of the at least one pair of side bulkheads (206) are attached to the bulkhead top portion (210) at a single bracket bulkhead attachment location (218).

7. The pressure vessel (200) according to any one of claims 1 to 5, further comprising: At least one pressure suppression mechanism (472) is configured to pressurize (470) the interior of the pressure vessel to seal the panel (300) to at least one of the pair of side bulkheads (206).

8. The pressure vessel (200) according to any one of claims 1 to 5, wherein: At least one of the panel (300) and the first plurality of panel supports (400) is configured for fail-safe purposes to prevent failure of the panel if one of the first plurality of panel supports fails.

9. The pressure vessel (200) according to claim 8, wherein: The fail-safe configuration includes at least one of the following: at least one of the first plurality of panel supports (400) having an axial strength capability to prevent failure of the panel (300) in the event of failure of another panel support of the first plurality of panel supports; at least one panel support of the first plurality of panel supports having a residual axial strength capacity and a residual axial stiffness capacity to prevent failure of the panel in the event of failure of the at least one panel support of the first plurality of panel supports; and The panel has a bending load capacity to prevent failure of the panel if one of the first plurality of panel supports fails.

10. The pressure vessel (200) according to any one of claims 1 to 5, wherein: The pressure vessel comprises at least one of a passenger cabin (112) and a cargo cabin (114) of an aircraft (100); and The panels (300) include skin panels defining an aerodynamic surface (116) of the aircraft and configured to withstand flight loads during pressurization of at least one of the passenger cabin and the cargo bay.

11. A method of loading a pressure vessel (200), the method comprising: internally pressurizing the pressure vessel at least partially enclosed by panels (300) having at least one panel span (324) extending between a pair of side bulkheads (206), each side bulkhead having a bulkhead top portion (210) non-contactingly adjacent the panels; generating an out-of-plane pressure load on the panel in response to internally pressurizing the pressure vessel; transferring the out-of-plane pressure load from the panel to the pair of side bulkheads using a first plurality of panel supports (400) coupling each of the side bulkheads to the panel at a first plurality of panel attachment nodes (342) distributed along the at least one panel span; as well as When the pressure vessel is internally pressurized, outward deflection of the first plurality of panel attachment nodes is limited to substantially equal deflection amounts (346), the outward deflection being limited by the first plurality of panel supports, the axial stiffness of the first plurality of panel supports being different between at least two of the panel supports in the first plurality of panel supports.

12. The method according to claim 11, further comprising: The out-of-plane pressure load is transferred from the panel (300) to at least one container rib (230) using a second plurality of panel supports (400), the second plurality of panel supports coupling a rib top portion (232) to a second plurality of panel attachment nodes (342) distributed along the at least one panel span (324), the at least one container rib being located between the pair of side bulkheads (206) and non-contactingly adjacent the panel.

13. The method according to claim 11, wherein Transferring the out-of-plane pressure load from the panel (300) to the pair of side bulkheads (206) includes: The out-of-plane pressure load is transferred using at least one panel support of the first plurality of panel supports (400), the at least one panel support having at least one of the following configurations: a cross-sectional area and corresponding axial stiffness that differs from the cross-sectional area and corresponding axial stiffness of one or more panel brackets of the remaining panel brackets of the first plurality of panel brackets coupling the pair of side bulkheads to the panel; and An elastic modulus and corresponding axial stiffness that are different from the elastic modulus and corresponding axial stiffness of one or more panel brackets in the first plurality of panel brackets that couple the pair of side bulkheads to the panel.

14. The method according to any one of claims 11 to 13, wherein In the event of a faulty bracket (456) occurring among the first plurality of panel brackets (400), the method further comprises at least one of the following steps: carrying an axial load in one or more remaining panel supports of the first plurality of panel supports that is higher than the axial load carried by any panel support of the first plurality of panel supports in the absence of failure to prevent failure of the panel (300) due to buckling; carrying an axial load in said failure bracket capable of preventing failure of said panel; as well as A bending load is carried in the panel that is higher than a bending load carried by the panel when none of the first plurality of panel supports fails to prevent failure of the panel due to buckling.

15. The method according to any one of claims 11 to 13, wherein The pressure vessel (200) comprises at least one of a passenger cabin (112) and a cargo compartment (114) of an aircraft (100), the panel (300) comprises an aerodynamic surface (116), and the method further comprises: The panels are used to withstand flight loads imposed on the panels during pressurization of at least one of the passenger cabin and the cargo compartment.

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