Composite door and method of forming same

Abstract

To provide a composite door of an air craft, and to provide a method of forming the composite door.SOLUTION: A composite door 100 comprises a composite frame 110, which comprises a first rail 111, a second rail 112, and crossbeams 113. The composite door 100 also comprises a first composite side beam 130, a second composite side beam 140, and a composite skin 150, connected to each of the crossbeams 113 of the composite frame 110, to the first composite side beam 130, and to the second composite side beam 140. The composite door 100 further comprises first composite edge fittings 120 and second composite edge fittings 122. Each first composite edge fitting is connected to a corresponding one of the crossbeams 113 of the composite frame 110, to the first composite side beam 130, and to the composite skin 150. Each second composite edge fitting is connected to a corresponding one of the crossbeams 113 of the composite frame 110, to the second composite side beam 140, and to the composite skin 150.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The presently disclosed subject matter relates to composite doors and methods of forming same. [Background technology]

[0002] Conventional doors used on vehicles such as aircraft are typically made of metal. Such doors are typically heavy, which is highly undesirable in many applications, such as aircraft. Furthermore, the metal components of such doors can be prone to corrosion and require special protection and periodic inspection, which can be resource-intensive. Furthermore, conventional doors typically include many different components connected by various types of fasteners. These components are manufactured separately, which makes the overall process associated with conventional doors more cumbersome and costly. Summary of the Invention

[0003] Therefore, an apparatus and method designed to address at least the above-mentioned concerns would be useful.

[0004] The following is a non-exhaustive list of examples of the subject matter of the present disclosure.

[0005] The composite door of the present disclosure includes a composite frame including a first rail, a second rail, and a cross beam connecting the first rail and the second rail. The composite door further includes a first composite stringer, a second composite stringer, and a composite skin panel connected to each of the cross beams of the composite frame and the first composite stringer and the second composite stringer. The composite door further includes first composite edge connection members. Each of the first composite edge connection members is connected to a corresponding one of the cross beams of the composite frame, the first composite stringer, and the composite skin panel. The composite door further includes second composite edge connection members. Each of the second composite edge connection members is connected to a corresponding one of the cross beams of the composite frame, the second composite stringer, and the composite skin panel.

[0006] The composite door 100 is lighter than conventional doors, such as metal doors, and more specifically, aluminum doors. The composite door 100 is less susceptible to environmental degradation (e.g., corrosion) than conventional metal doors. Furthermore, the composite door 100 is comprised of fewer components than conventional doors, such as the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150. The composite skin 150 insulates and protects the interior from the external environment. In turn, the composite frame 110, the first composite stringer 130, and the second composite stringer 140 provide support for the composite skin 150, such that the composite skin 150 can withstand pressure differentials on both sides of the composite door 100. The first composite edge connection member 120 and the second composite edge connection member 122 connect the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150 and function to provide increased mechanical support for these components.

[0007] The present disclosure further discloses a method for forming a composite door. The method includes forming a frame precursor sheet having flaps by cutting a prepreg sheet. The method further includes placing the frame precursor sheet along a door forming tool. The door forming tool includes a frame surface and flap support portions non-parallel to the frame surface. By placing the frame precursor sheet along the door forming tool, each of the flaps of the frame precursor sheet is formed into a shape complementary to a corresponding one of the flap support portions. The method further includes forming a composite frame by curing the frame precursor sheet placed along the door forming tool. The method further includes removing the composite frame from the door forming tool and interconnecting the composite frame, a first composite edge connecting member, a second composite edge connecting member, a first composite stringer, a second composite stringer, and a composite skin.

[0008] The various components of the composite door 100 are formed from prepreg sheets. Prepreg sheets allow for more precise control of material consistency than, for example, composite layup. For example, the composite frame 110 is formed from prepreg sheets 400 by cutting and molding the prepreg sheets into the shape of the composite frame 110. Furthermore, such prepreg sheets allow for the integral formation of distinct features, such as the various components of the composite frame 110. The composite door 100 is lighter than conventional doors, such as metal doors, and more specifically, aluminum doors. The composite door 100 is less susceptible to environmental degradation (e.g., corrosion) than conventional metal doors. Furthermore, the composite door 100 is comprised of fewer components than conventional doors, such as, for example, the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150. [Brief explanation of the drawings]

[0009] In the following description, reference will be made to the accompanying drawings, which are not necessarily drawn to scale and in which like reference numerals are used throughout the several drawings to refer to the same or similar parts.

[0010] [Figure 1] 1 is a block diagram illustrating a composite door according to one or more embodiments of the present disclosed subject matter. [Figure 2A] 2 is a schematic perspective view of the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 2B] 2 is a schematic exploded view illustrating the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 2C] 2 is a schematic top view of the composite door of FIG. 1 in accordance with one or more embodiments of the present disclosed subject matter. [Figure 2D-2E] 2A-2C are two schematic cross-sectional views illustrating the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 2F-2G] 2 is a schematic cross-sectional view illustrating two portions of the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 2H] FIG. 2 is a schematic perspective view of a portion of the composite door of FIG. 1 showing one of the first composite edge connection members attached to the composite skin, cross beam, and first composite stringer in accordance with one or more embodiments of the present subject matter. [Figures 2I-2J] FIG. 2 is a schematic perspective view of a portion of the composite door of FIG. 1 , showing a composite skin attached to a cross beam, a first composite stringer, and a second composite stringer, in accordance with one or more embodiments of the present disclosure. [Figure 2K] FIG. 2 is a schematic cross-sectional view of a portion of the composite door of FIG. 1 , showing a composite skin adhesively connected to a cross beam, a first composite stringer, and a second composite stringer, in accordance with one or more embodiments of the present disclosure. [Figure 2L] 2 is a schematic cross-sectional view of a portion of the composite door of FIG. 1 , illustrating a first composite edge connection member connected to the cross beam, the first composite stringer, and the composite skin using a first amount of adhesive, in accordance with one or more embodiments of the present subject matter. [Figure 2M] FIG. 2 is a schematic cross-sectional view of a portion of the composite door of FIG. 1 , illustrating a second composite edge connection member connected to the cross beam, the second composite stringer, and the composite skin using a second amount of adhesive, in accordance with one or more embodiments of the present subject matter. [Figure 3A] 2 is a schematic cross-sectional view of a portion of the composite door of FIG. 1, illustrating various features of the composite frame, in accordance with one or more embodiments of the present disclosed subject matter. [Figure 3B] 2 is a schematic cross-sectional view of the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 3C-3D] 2 is a schematic cross-sectional view of two sections of the composite door of FIG. 1 showing different orientations of the crossbeam supports in accordance with one or more embodiments of the present disclosed subject matter. [Figure 3E] 2 is a schematic cross-sectional view of the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 3F-3G] 2 is a schematic cross-sectional view of two sections of the composite door of FIG. 1 showing the crossbeam supports in the same orientation, according to one or more embodiments of the present disclosed subject matter. [Figure 3H]2 is a schematic cross-sectional view of a portion of the composite door of FIG. 1, illustrating various dimensional features of the composite frame, in accordance with one or more embodiments of the present disclosed subject matter. [Figure 4A] 2 is a schematic top view of the composite door of FIG. 1 showing abutment connection members in accordance with one or more embodiments of the present disclosed subject matter; [Figure 4B] 2 is a schematic cross-sectional view of the composite door of FIG. 1 showing abutment connection members in accordance with one or more embodiments of the present disclosed subject matter. [Figure 4C] 2 is a schematic cross-sectional view of a portion of the composite door of FIG. 1 showing abutting connecting members positioned opposite other members in the composite door in accordance with one or more embodiments of the present disclosure. [Figure 4D-4E] 2A-2C are two schematic diagrams illustrating the abutment connection member of the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 5] 2 is a block diagram illustrating a method according to one or more embodiments of the present disclosed subject matter for forming the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 6A] 2 is a schematic top view illustrating a prepreg sheet used to form the composite door of FIG. 1 in accordance with one or more embodiments of the present disclosed subject matter. [Figure 6B] 6B is a schematic top view illustrating a frame precursor sheet formed from the prepreg sheet of FIG. 6A used to form the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 6C] 6B is a schematic top view illustrating a frame precursor sheet formed from the prepreg sheet of FIG. 6A used to form the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 7A] 2 is a schematic perspective view of a door forming tool used to form the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 7B] 2 is a schematic cross-sectional view illustrating a door forming tool used to form the composite door of FIG. 1 according to one or more embodiments of the present disclosed subject matter. [Figure 7C-7D] 7B is a schematic cross-sectional view of the door forming tool of FIG. 7A showing a frame precursor sheet and a skin prepreg sheet processed using the door forming tool for use in making the composite door of FIG. 1 according to one or more embodiments of the present subject matter. [Figures 7E-7F] 7B is a schematic perspective view of the door forming tool of FIG. 7A showing a first stringer prepreg sheet, a second stringer prepreg sheet, and a skin prepreg sheet processed using the door forming tool for use in making the composite door of FIG. 1 according to one or more embodiments of the present subject matter. [Figure 8] FIG. 1 is a block diagram illustrating how an aircraft can be made and used. [Figure 9] 1 is a schematic diagram showing an aircraft; DETAILED DESCRIPTION OF THE INVENTION

[0011] In FIG. 1 , solid lines connecting various elements and / or components may represent mechanical, electrical, fluid, optical, electromagnetic, and other connections and / or combinations thereof. As used herein, "connected" includes both direct and indirect connections. For example, component A may be directly connected to component B or indirectly connected, for example, via another component C. It should be noted that not all relationships between the various disclosed elements are necessarily shown. Thus, connections other than those shown in the block diagram may exist. Dashed lines connecting various elements and / or components may represent connections similar in function and purpose to those represented by solid lines. However, dashed connections may be optional or may represent alternative embodiments of the subject matter of the present disclosure. Similarly, dashed elements and / or components may represent alternative embodiments of the subject matter of the present disclosure. One or more elements shown with solid and / or dashed lines may be omitted from a particular embodiment without departing from the scope of the present disclosure. Extraneous elements, if any, are represented by dotted lines. Hypothetical (imaginary) elements may be depicted for clarity. As will be appreciated by those skilled in the art, some of the features shown in FIG. 1 may be combined in various ways without including other features described in FIG. 1, other figures, and / or the accompanying disclosure, without such combinations necessarily being explicitly set forth in this disclosure. Similarly, additional features not limited to the examples shown may be combined with some or all of the features shown and described herein.

[0012] In the above-described Figures 8 and 9, blocks may represent steps and / or portions thereof, and lines connecting various blocks do not imply a particular order or dependency relationship between those steps or portions thereof. Blocks shown with dashed lines represent alternative steps and / or portions thereof. Dashed lines connecting various blocks, if any, indicate alternative dependencies between steps or portions thereof. It should be noted that not all dependencies between the various steps disclosed are necessarily shown. The descriptions of steps in Figures 8 and 9 and the method described herein should not be construed as determining the absolute order in which those steps should be performed. Rather, while one exemplary order is shown, it should be understood that the order of steps can be changed as appropriate. Thus, some steps may be performed in a different order or simultaneously. Furthermore, one skilled in the art will recognize that not all of the steps described need to be performed.

[0013] In the following description, numerous specific details are presented to provide a thorough understanding of the concepts of the disclosure. However, the disclosure may be practiced without some or all of these details. In other instances, details of well-known devices and / or processes are omitted to avoid unnecessarily obscuring the disclosure. While some concepts are described in connection with specific examples, it will be understood that these examples are not intended to limit the disclosure.

[0014] Unless otherwise specified, the terms "first," "second," etc., as used herein are used merely as labels and do not impose any ordering, positional, or hierarchical requirements on the items referred to by these terms. Furthermore, a reference to, for example, a "second" item does not require or exclude the presence of, for example, a "first" item or lower ordinal item, and / or a "third" or higher ordinal item.

[0015] As used herein, the term "one or more embodiments" means that one or more features, structures, or characteristics described in connection with the embodiment are included in at least one embodiment. The phrase "one or more embodiments" used in various places in this specification may or may not refer to the same embodiment.

[0016] As used herein, a system, device, structure, article, element, component, or hardware that is "configured to" perform a particular function refers to one that can perform that particular function without any modification, and not one that requires any modification in order to perform that particular function. In other words, a system, device, structure, article, element, component, or hardware that is "configured" to perform a particular function refers to one that is specifically selected, made, implemented, utilized, programmed, and / or designed to perform that particular function. As used herein, "configured" refers to a characteristic that the system, device, structure, article, element, component, or hardware already possesses, which characteristic enables the system, device, structure, article, element, component, or hardware to perform that particular function without any modification. In this disclosure, a system, device, structure, article, element, component, or hardware that is "configured" to perform a particular function may additionally or alternatively be described as being "adapted to" and / or "operative to" perform that function.

[0017] The following provides illustrative, non-limiting examples of the subject matter of the present disclosure.

[0018] 1 generally, and specifically, for example, with reference to Figures 2A-3H, a composite door 100 is shown by way of example and not limitation. The composite door 100 includes a composite frame 110, which includes a first rail 111, a second rail 112, and a plurality of crossbeams 113 connecting the first rail 111 and the second rail 112. The composite door 100 further includes a first composite side beam 130, a second composite side beam 140, and a composite skin 150. The composite skin is connected to each crossbeam 113 of the composite frame 110 and to the first composite side beam 130 and the second composite side beam 140. The composite door 100 further includes a plurality of first composite edge fittings 120, each connected to a corresponding one of the cross beams 113 of the composite frame 110, a first composite stringer 130, and a composite skin 150. The composite door 100 further includes a plurality of second composite edge fittings 122, each connected to a corresponding one of the cross beams 113 of the composite frame 110, a second composite stringer 140, and a composite skin 150. The above description in this paragraph characterizes Example 1 of the subject matter of the present disclosure.

[0019] The composite door 100 is lighter than conventional doors, such as metal doors, and more specifically, aluminum doors. The composite door 100 is less susceptible to environmental degradation (e.g., corrosion) than conventional metal doors. Furthermore, the composite door 100 is comprised of fewer components than conventional doors, such as the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150. The composite skin 150 insulates and protects the interior from the external environment. In turn, the composite frame 110, the first composite stringer 130, and the second composite stringer 140 provide support for the composite skin 150, such that the composite skin 150 can withstand pressure differentials on both sides of the composite door 100. The first composite edge connection member 120 and the second composite edge connection member 122 connect the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150 and function to provide increased mechanical support for these components.

[0020] The first rail 111 and the second rail 112 of the composite frame 110 extend along the height of the composite door 100, for example, from the first skin edge 151 to the second skin edge 152 of the composite panel 150. In some embodiments, the first rail 111 and the second rail 112 extend parallel to one another. More specifically, the first rail 111 extends along and is connected to the first composite stringer 130. The second rail 112 extends along and is connected to the second composite stringer 140. The first rail 111 is interconnected to the composite panel 150 by the first composite stringer 130. The second rail 112 is interconnected to the composite panel 150 by the second composite stringer 140.

[0021] A plurality of cross beams 113 extending between the first rail 111 and the second rail 112 are connected together by the first rail 111 and the second rail 112. In some embodiments, the first rail 111, the second rail 112, and the cross beams 113 are all formed from the same material, for example, a prepreg sheet, as described below. Therefore, the first rail 111, the second rail 112, and the cross beams 113 do not need to be connected again.

[0022] The multiple crossbeams 113 are distributed throughout the height of the composite door 100. In some embodiments, the crossbeams 113 are evenly spaced to provide uniform support for the composite skin 150. The crossbeams 113 are directly connected to the composite skin 150 at portions thereof. While Figures 2A and 2B show the composite door 100 including eight crossbeams 113, any number of crossbeams 113 is within the contemplated range of implementation. The number of crossbeams 113 depends on the thickness of the composite door 100 (defined in part by the crossbeams 113) and the height of the composite door 100.

[0023] The first composite stringer 130 and the second composite stringer 140 extend along the height of the composite door 100, for example, from the first skin edge 151 to the second skin edge 152 of the composite skin 150. In some embodiments, the first composite stringer 130 and the second composite stringer 140 extend parallel to one another. The first composite stringer 130 and the second composite stringer 140 support the composite skin 150 along its edges. In some embodiments, the first composite stringer 130 and the second composite stringer 140 have the same shape and are interchangeable. For example, the radii of curvature of the first composite stringer 130 and the second composite stringer 140 are continuous.

[0024] Each first composite edge connection member 120 interconnects a corresponding one of the cross beams 113 of the composite frame 110, a first composite stringer 130, and a composite skin panel 150. Similarly, each second composite edge connection member 122 interconnects a corresponding one of the cross beams 113, a second composite stringer 140, and a composite skin panel 150. The provision of the first composite edge connection members 120 and the second composite edge connection members 122 simplifies the design of the composite frame 110 while still providing a strong connection between the composite frame 110, the first composite stringer 130, and the composite skin panel 150. For example, each of the first composite edge connection members 120 and the second composite edge connection members 122 has multiple sides, as described below, making them well-designed to connect various components of the composite door 100.

[0025] 1 generally, and specifically, for example, with reference to FIGS. 2D, 2F, and 2G, by way of example and not limitation, a first composite stringer 130 is connected to a first rail 111 of a composite frame 110, and a second composite stringer 140 is connected to a second rail 112 of the composite frame 110. The foregoing description in this paragraph characterizes Example 2 of the present disclosure, which also encompasses Example 1 described above.

[0026] Connecting the first composite stringer 130 and the second composite stringer 140 to the composite frame 110 improves the rigidity of the composite frame 110, particularly around the first rail 111 and the second rail 112. This connection makes it possible to construct the composite frame 110, the first composite stringer 130, and the second composite stringer 140 using lighter structural materials.

[0027] In some embodiments, the first rail 111 of the composite frame 110 directly interfaces with and overlaps the first composite stringer 130, as shown in FIG. 2G. For example, the first rail 111 is disposed between one of the first composite edge connection members 120 (e.g., one of the two first side walls 124 of the corresponding first composite edge connection member) and the first composite stringer 130. In some embodiments, the connection between the first rail 111 and the first composite stringer 130 is also connected to one of the first composite edge connection members 120.

[0028] Furthermore, in some embodiments, the second rail 112 of the composite frame 110 directly interfaces with and overlaps the second composite stringer 140, as shown in FIG. 2F . For example, the second rail 112 is disposed between one of the second composite edge connection members 122 (e.g., one of the two second side walls 127 of the corresponding second composite edge connection member) and the second composite stringer 140. In some embodiments, the connection between the second rail 112 and the second composite stringer 140 is also connected to one of the second composite edge connection members 122.

[0029] 1 generally, and, for example, with reference to FIG. 2G specifically, by way of example and not limitation, a first composite stringer 130 includes a first-beam base 131 and two first-beam sides 132 non-parallel to the first stringer base 131. The first stringer base 131 is connected to each of the first composite edge connection members 120. One of the two first stringer sides 132 is connected to the first rail 111 of the composite frame 110. The other of the two first stringer sides 132 is connected to the composite skin 150. The preceding description in this paragraph characterizes Example 3 of the present disclosure, which encompasses either Example 1 or Example 2 described above.

[0030] The connection of the first composite stringer 130 to the composite frame 110 improves the stiffness of the composite frame 110, particularly around the first rail 111 and around the composite skin panel 150 and first composite edge connection member 120. Furthermore, the first stringer base portion 131 provides spacing between the two first stringer side portions 132, thereby providing spacing between the first rail 111 and the composite skin panel 150, improving the mechanical strength of the composite door 100 as a whole. This connection allows the composite frame 110, first composite stringer 130, and composite skin panel 150 to be constructed using lighter structural materials.

[0031] 2G, the first stringer base portion 131 is a connecting portion between the two first stringer side portions 132. The two first stringer side portions 132 are non-parallel to the first stringer base portion 131. In some embodiments, for example, when the first rail 111 and the composite skin 150 of the portion opposite it are parallel, the two first stringer side portions 132 are parallel to each other.

[0032] 1 generally, and, for example, with reference to FIG. 2F specifically, by way of example and not limitation, a second composite stringer 140 includes a second stringer base portion 141 and two second stringer side portions 142 non-parallel to the second stringer base portion 141. The second stringer base portion 141 is connected to each of the second composite edge connection members 122. One of the two second stringer side portions 142 is connected to the second rail 112 of the composite frame 110. The other of the two second stringer side portions 142 is connected to the composite skin 150. The above description in this paragraph characterizes Example 4 of the present disclosure, which encompasses any of Examples 1 to 3 described above.

[0033] The connection of the second composite stringer 140 to the composite frame 110 improves the stiffness of the composite frame 110, particularly around the second rail 112 and around the composite skin panel 150 and the second composite edge connecting member 122. Furthermore, the second stringer base portion 141 provides spacing between the two second stringer side portions 142, thereby providing spacing between the second rail 112 and the composite skin panel 150, improving the mechanical strength of the composite door 100 as a whole. This connection allows the composite frame 110, second composite stringer 140, second composite edge connecting member 122, and composite skin panel 150 to be constructed using lighter structural materials.

[0034] 2F, the second stringer base portion 141 is a connecting portion between the two second stringer side portions 142. The two second stringer side portions 142 are non-parallel to the second stringer base portion 141. In some embodiments, for example, when the second rail 112 and the composite skin 150 of the opposing portion are parallel, the two second stringer side portions 142 are parallel to each other.

[0035] 1 generally, and, for example, with reference to FIG. 3A specifically, by way of example and not limitation, each cross beam 113 of composite frame 110 has a major portion 114 that extends to composite skin 150 in a non-parallel orientation relative to first rail 111 and second rail 112. The preceding description in this paragraph characterizes Example 5 of the present disclosure, which encompasses any of Examples 1-4 described above.

[0036] The main portions 114 provide spacing between the first rail 111 and the composite skin 150 and between the second rail 112 and the composite skin 150, thereby improving the mechanical strength and load-bearing capacity of the composite door 100 as a whole. This spacing corresponds to (e.g., is defined by) the length of the first stringer base portion 131 of the first composite stringer 130, the length of the second stringer base portion 141 of the second composite stringer 140, the length of the first end wall 125 of each first composite edge connection member 120, and the length of the second end wall 128 of each second composite edge connection member 122. The thickness of the composite door 100 is determined by the length of the main portions 114. In some embodiments, each main portion 114 extends substantially perpendicular (e.g., between 80° and 100°) to one or both of the first rail 111 (or second rail 112) and the composite skin 150, as shown, for example, in FIG. 3A.

[0037] 1 generally, and specifically, for example, with reference to FIG. 3A , by way of example and not limitation, main portion 114 of each cross beam 113 is the portion extending from composite skin 150 to each of first rail 111 and second rail 112. The preceding description in this paragraph characterizes Example 6 of the present disclosure, which also encompasses Example 5 described above.

[0038] The main portions 114 provide spacing between the first rail 111 and the composite skin 150 and between the second rail 112 and the composite skin 150, thereby improving the mechanical strength and load-bearing capacity of the composite door 100 as a whole. This spacing corresponds to (e.g., is defined by) the length of the first stringer base portion 131 of the first composite stringer 130, the length of the second stringer base portion 141 of the second composite stringer 140, the length of the first end wall 125 of each first composite edge connection member 120, and the length of the second end wall 128 of each second composite edge connection member 122. The thickness of the composite door 100 is determined by the length of the main portions 114. In some embodiments, each main portion 114 extends substantially perpendicular (e.g., between 80° and 100°) to one or both of the first rail 111 (or second rail 112) and the composite skin 150, as shown, for example, in FIG. 3A.

[0039] 1 generally, and, for example, with reference to FIG. 3A specifically, by way of example and not limitation, each cross beam 113 of the composite frame 110 further includes a skin support portion 115 extending non-parallel from the main portion 114 of the cross beam 113. The skin support portion 115 of each cross beam 113 is connected to a composite skin 150. The preceding description in this paragraph characterizes Example 7 of the present disclosure, which encompasses either Example 5 or Example 6 described above.

[0040] The skin support portion 115 is a portion that forms an interface with the composite skin 150 when the composite skin 150 is attached to the composite frame 110, and is a portion that supports the composite skin 150, for example, between the first composite stringer 130 and the second composite stringer 140. The attachment and support described above allows the composite skin 150 to withstand a critical load (e.g., a pressure difference on both sides of the composite skin 150) even if the composite skin 150 is made of a lightweight material.

[0041] In some embodiments, each skin support 115 conforms to the shape of the opposing composite skin 150, thereby defining an attachment interface between the composite skin 150 and the composite frame 110. The skin support 115 extends between the first composite stringer 130 and the second composite stringer 140, or at least between the first composite edge connection member 120 and the second composite edge connection member 122.

[0042] 1 generally, and specifically, for example, with reference to Figures 3A, 3C, 3D, 3F, and 3G, by way of example and not limitation, the skin support portion 115 of each cross beam 113 extends from the main portion 114 of that cross beam 113 along the composite skin 150. The preceding description in this paragraph characterizes Example 8 of the present disclosure, which also encompasses Example 7 described above.

[0043] The skin support portion 115 is a portion that forms an interface with the composite skin 150 when the composite skin 150 is attached to the composite frame 110, and is a portion that supports the composite skin 150, for example, between the first composite stringer 130 and the second composite stringer 140. The attachment and support described above allows the composite skin 150 to withstand a critical load (e.g., a pressure difference on both sides of the composite skin 150) even if the composite skin 150 is made of a lightweight material.

[0044] In some embodiments, each skin support 115 conforms to the shape of the opposing composite skin 150, thereby defining a bonded interface between the composite skin 150 and the composite frame 110. The skin support 115 extends between the first composite stringer 130 and the second composite stringer 140, or at least between the first composite edge connection member 120 and the second composite edge connection member 122.

[0045] 1 as a whole, and specifically, for example, with reference to FIGS. 3B-3D , by way of example and not limitation, the multiple skin support portions 115 of the multiple cross beams 113 include a first skin support portion 115a and a second skin support portion 115b. The first skin support portion 115a of the cross beam 113 extends from the main portion 114 of the cross beam 113 in a first direction along the composite skin 150. The second skin support portion 115b of the cross beam 113 extends from the main portion 114 of the cross beam 113 in a second direction opposite to the first direction along the composite skin 150. The above description in this paragraph characterizes Example 9 of the summary of the present disclosure, and Example 9 encompasses either Example 7 or Example 8 described above.

[0046] The first and second skin support portions 115a, 115b extend in opposite directions to each other, thereby uniformly distributing and supporting the load of the composite skin 150. In other words, the first and second skin support portions 115a, 115b support the composite skin 150 symmetrically between the first skin edge 151 and the second skin edge 152. FIG. 3B shows a composite door 100 including four first skin support portions 115a extending toward the first skin edge 151 and four second skin support portions 115b extending toward the second skin edge 152. In some embodiments, the first and second skin support portions 115a, 115b are paired, and the skin support portions in each pair are positioned equidistant from the center of the composite door 100.

[0047] 1 generally, and, for example, with reference to FIGS. 2E and 3A specifically, by way of example and not limitation, first rail 111 and second rail 112 are each parallel to composite skin 150. The preceding description in this paragraph characterizes Example 10 of the present disclosure, which encompasses any of Examples 1-9 described above.

[0048] The first rail 111 and the second rail 112, spaced apart from the composite skin 150, form the structural unibody of the composite door 100, effectively creating a truss-like structure. Furthermore, when the first rail 111 and the second rail 112 are each parallel to the composite skin 150, the composite door 100 has a uniform thickness defined by the spacing between the rails. In some embodiments, the first rail 111 and the second rail 112 are each parallel to the composite skin 150, and in some embodiments, they are curved, for example, as shown in FIG. 2E.

[0049] 1 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, each first composite edge connecting member 120 has a first bottom wall 123, two first side walls 124, and a first end wall 125. The two first side walls 124 are connected to one another by the first bottom wall 123 and by the first end wall 125. One of the first side walls 124 is connected to the composite frame 110. The preceding description in this paragraph characterizes Example 11 of the present disclosure, which encompasses any of Examples 1-4 described above.

[0050] The multiple walls of the first composite edge connecting member 120 (e.g., the first bottom wall 123, the two first side walls 124, and the first end wall 125) allow multiple components of the composite door 100 to be interconnected. This connection using the first composite edge connecting member 120 facilitates the design and manufacture of other components of the composite door 100.

[0051] In some embodiments, one of the two first side walls 124 is connected to a cross beam 113 of the composite frame 110, as shown in FIG. 2H. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0052] 1 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, the other of the two first side walls 124 of each first composite edge connection member 120 is connected to the composite skin 150. The foregoing description in this paragraph characterizes Example 12 of the present disclosure, which also encompasses Example 11 described above.

[0053] The multiple walls of the first composite edge connecting member 120 allow multiple components of the composite door 100 to be connected to one another. For example, the combination of the two first side walls 124 of the first composite edge connecting member 120 connects the composite skin panel 150 to the composite frame 110. In particular, each first composite edge connecting member 120 supports the portion of the composite skin panel 150 facing the connecting member relative to the composite frame 110, thereby improving the strength of the composite skin panel 150. The use of the first composite edge connecting member 120 in this manner facilitates the design and manufacture of other components of the composite door 100. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0054] 1 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, the first end wall 125 of each first composite edge connection member 120 is connected to a first composite stringer 130. The preceding description in this paragraph characterizes Example 13 of the present disclosure, which encompasses either Example 11 or Example 12 described above.

[0055] The multiple walls of the first composite edge connecting member 120 allow multiple components of the composite door 100 to be connected to one another. For example, the combination of the two first side walls 124 and the first end wall 125 of the first composite edge connecting member 120 connects the first composite stringer 130 and the composite frame 110 to one another. In particular, each first composite edge connecting member 120 supports the corresponding portion of the composite frame 110 and the composite skin 150 relative to the first composite stringer 130, thereby improving the strength of each component at the joint interface. Using the first composite edge connecting member 120 in this manner facilitates the design and manufacture of other components of the composite door 100. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0056] 1 generally, and specifically, for example, with reference to FIGS. 2H and 2I , by way of example and not limitation, each cross beam 113 of a composite frame 110 has a main portion 114 and a skin support portion 115. The skin support portion 115 of each cross beam 113 is connected to and non-parallel to the main portion 114 of that cross beam 113. The first bottom wall 123 of each first composite edge connection member 120 is connected to the main portion 114 of the cross beam 113. The preceding description in this paragraph characterizes Example 14 of the present disclosure, which encompasses any of Examples 11-13 described above.

[0057] The different walls of the first composite edge connecting member 120 allow multiple components of the composite door 100 to be connected to one another. For example, the combination of one of the two first side walls 124 and the first bottom wall 123 of the first composite edge connecting member 120 can firmly connect the composite frame 110, which is one of the main structural components of the composite door 100. In particular, each of the first composite edge connecting members 120 supports the portion of the composite frame 110 facing the connecting member, thereby improving the strength of each component of the composite frame 110 (e.g., the main section 114). Using the first composite edge connecting member 120 to connect components in this manner facilitates the design and manufacture of other components of the composite door 100. This connection can be formed by various means, such as adhesives and fasteners, as described below.

[0058] 1 generally, and specifically, for example, with reference to Figures 2H-2J, by way of example and not limitation, the two first side walls 124 of each first composite edge connection member 120 and the skin support portion 115 of the corresponding cross beam 113 extend in opposite directions. The preceding description in this paragraph characterizes Example 15 of the present disclosure, which also encompasses Example 14 described above.

[0059] One of the two first side walls 124 of each first composite edge connection member 120 is connected to the composite skin panel 150, for example, as shown in FIG. 2H. Furthermore, each skin support 115 is connected to the composite skin panel 150, for example, as shown in FIGS. 2I and 2H. When the two first side walls 124 of each first composite edge connection member 120 and the corresponding skin support 115 extend in opposite directions, the composite skin panel 150 is collectively supported by these members in the combined area of ​​the two first side walls 124 and the skin support 115. In this way, most of the composite skin panel 150 is supported.

[0060] 1 generally, and, for example, with reference to FIGS. 2C and 2E specifically, by way of example and not limitation, composite skin 150 is curved. First composite stringer 130 and second composite stringer 140 each have a shape complementary to composite skin 150. The preceding description in this paragraph characterizes Example 16 of the present disclosure, which encompasses any of Examples 1-15 described above.

[0061] Composite door 100 is used in a variety of applications, such as aircraft. In some embodiments, the shape of composite door 100 corresponds to the shape of a surrounding structure, such as an aircraft fuselage. A typical aircraft fuselage cross-section has, for example, a curved profile. Thus, composite skin 150 is non-planar to form a non-planar composite door. First composite stringer 130 and second composite stringer 140 conform to the shape of composite skin 150 and provide lateral support for composite door 100. In some embodiments, composite skin 150 has a continuous radius of curvature from first skin edge 151 to second skin edge 152. Alternatively, the radius of curvature may vary along the way.

[0062] 1 generally, and, for example, with reference to Figures 2C and 2E specifically, by way of example and not limitation, each cross beam 113 of composite frame 110 has a shape complementary to composite skin 150. The foregoing description in this paragraph characterizes Example 17 of the present disclosure, which encompasses any of Examples 1-16 described above.

[0063] Each cross beam 113 of the composite frame 110 conforms to the shape of the composite skin 150 and supports the composite skin 150 between the ends of the composite door 100. This support allows the composite skin 150 to be constructed of lighter structural materials, thereby reducing the overall weight of the composite door 100. In some embodiments, each cross beam 113 is aligned with and in contact with a corresponding portion of the composite skin 150. For example, the cross beam 113 includes a skin support 115 that is aligned with and in contact with the composite skin 150.

[0064] 1 generally, and, for example, with reference to FIGS. 2I and 2H specifically, by way of example and not limitation, composite skin 150 is connected to each cross beam 113 of composite frame 110 and to first composite stringer 130 and second composite stringer 140 using fasteners 190. The foregoing description in this paragraph characterizes Example 18 of the present disclosure, which encompasses any of Examples 1-17 described above.

[0065] Fasteners 190 may be used to connect various components of composite door 100 together and to transfer loads between these components, such as between composite skin 150 and stringer 113, between composite skin 150 and first composite stringer 130, and between composite skin 150 and second composite stringer 140. Fasteners 190 may also be used to connect components made of different types of materials together, such as composite and metal. Examples of fasteners 190 include, but are not limited to, rivets, bolt and nut connections, etc. Fasteners 190 are installed during fabrication of composite door 100.

[0066] 1 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, each first composite edge connection member 120 is connected to a corresponding one of the cross beams 113 of the composite frame 110, to a first composite stringer 130, and to a composite skin panel 150 using a first set of fasteners 190. Each second composite edge connection member 122 is connected to a corresponding one of the cross beams 113 of the composite frame 110, to a second composite stringer 140, and to a composite skin panel 150 using a second set of fasteners 190. The preceding description in this paragraph characterizes Example 19 of the present disclosure, which also encompasses Example 18 described above.

[0067] The first composite edge connection members 120 and the second composite edge connection members 122, along with the fasteners 190, can be used to interconnect various components of the composite door 100 and transfer loads between these components, such as between each first composite edge connection member 120 and the cross beam 113, between each first composite edge connection member 120 and the first composite stringer 130, and between each first composite edge connection member 120 and the composite skin 150. Additionally, the fasteners 190 can be used to interconnect components made of different types of materials, such as composite and metal. Examples of fasteners 190 include, but are not limited to, rivets, bolt and nut connections, etc. The fasteners 190 are installed during fabrication of the composite door 100.

[0068] 1 generally, and, for example, FIG. 2K specifically, by way of example and not limitation, composite skin 150 is connected to each cross beam 113 of composite frame 110 and first and second composite stringers 130 and 140 using adhesive 192. The foregoing description in this paragraph characterizes Example 20 of the present disclosure, which encompasses any of Examples 1-19 described above.

[0069] The adhesive 192 allows for interconnection and load transfer between the various components of the composite door 100 without requiring the creation of holes or other irregularities in the components. Additionally, the adhesive 192 typically weighs less than other types of fasteners, which is important in various applications, such as aircraft. Referring to FIG. 2K, adhesive 192 is applied between the composite skin 150 and each of the stringers 113, connecting the composite skin 150 to each of the stringers 113. Adhesive 192 is also applied between the composite skin 150 and the first composite stringer 130, for example, along the entire length of the first composite stringer 130. Adhesive 192 is also applied between the composite skin 150 and the second composite stringer 140, for example, along the entire length of the second composite stringer 140.

[0070] 1 generally, and, for example, with reference to FIGS. 2L and 2M specifically, by way of example and not limitation, each first composite edge connection member 120 is connected to a corresponding one of the cross beams 113 of the composite frame 110, a first composite stringer 130, and a composite skin panel 150 with a first amount of adhesive 192. Each second composite edge connection member 122 is connected to a corresponding one of the cross beams 113 of the composite frame 110, a second composite stringer 140, and a composite skin panel 150 with a second amount of adhesive 192. The preceding description in this paragraph characterizes Example 21 of the present subject matter, which also encompasses Example 20 described above.

[0071] The adhesive 192 allows for interconnection and load transfer between the various components of the composite door 100 without requiring the creation of holes or other irregularities in the components. Additionally, the adhesive 192 generally weighs less than other types of fasteners, which is important in various applications, such as aircraft. The first composite edge connecting member 120 and the second composite edge connecting member 122, along with the adhesive 192, can be used to interconnect the various components of the composite door 100 and transfer loads between these components.

[0072] 2L , a first amount of adhesive 192 is applied between each first composite edge connection member 120 and a corresponding one of the cross beams 113 of the composite frame 110, connecting the connection member to the corresponding cross beam. A first amount of adhesive 192 is also applied between each first composite edge connection member 120 and a first composite stringer 130, connecting the connection member to the first composite stringer 130. A first amount of adhesive 192 is also applied between each first composite edge connection member 120 and a composite panel 150, connecting the connection member to the composite panel 150.

[0073] 2M , a second amount of adhesive 192 is applied between each second composite edge connection member 122 and a corresponding one of the cross beams 113 of the composite frame 110, connecting the connection member to the corresponding cross beam. A second amount of adhesive 192 is also applied between each second composite edge connection member 122 and a second composite stringer 140, connecting the connection member to the second composite stringer 140. A second amount of adhesive 192 is also applied between each second composite edge connection member 122 and a composite panel 150, connecting the connection member to the composite panel 150.

[0074] 1 generally, and, for example, with reference to Figures 4A-4E specifically, by way of example and not limitation, composite door 100 further includes stop fittings 180, some of which are connected to first composite stringer 130 and some of which are connected to second composite stringer 140. The foregoing description in this paragraph characterizes Example 22 of the present disclosure, which encompasses any of Examples 1-21 described above.

[0075] The abutment connecting member 180 is used to attach the composite door 100 to another member, such as an aircraft fuselage. The abutment connecting member 180 is configured to support the composite door 100 relative to such a member. The abutment connecting member 180 is configured to couple or otherwise attach to a connecting member provided on such a member.

[0076] 1 generally, and, for example, with reference to FIG. 4A specifically, by way of example and not limitation, each connecting member 180 is aligned with and positioned above a corresponding one of the cross beams 113 of the composite frame 110. The preceding description in this paragraph characterizes Example 23 of the present disclosure, which also encompasses Example 22 described above.

[0077] The abutment connecting member 180 allows the composite door 100 to be attached to an external member, such as an aircraft fuselage, and transfers loads between the composite door 100 and the external member. The cross beam 113 is aligned with the abutment connecting member 180 to facilitate load transfer and redistribute loads within the composite door 100. In some embodiments, the abutment connecting member 180 is indirectly or directly attached to the cross beam 113. In some embodiments, the abutment connecting member 180 is indirectly or directly attached to other members of the composite door 100, such as the first composite edge connecting member 120, the second composite edge connecting member 122, the first composite stringer 130, and / or the second composite stringer 140.

[0078] 1 generally, and, for example, with reference to Figures 4B and 4C specifically, by way of example and not limitation, each connecting member 180 is aligned with and positioned above a corresponding one of the first composite edge connecting members 120 or a corresponding one of the second composite edge connecting members 122. The preceding description in this paragraph characterizes Example 24 of the present disclosure, which encompasses either Example 22 or 23 described above.

[0079] The abutment connecting member 180 allows the composite door 100 to be attached to an external member, such as an aircraft fuselage, and transfers loads between the composite door 100 and the external member. The first composite edge connecting member 120 and the second composite edge connecting member 122 are aligned with the abutment connecting member 180 to facilitate load transfer and redistribute loads within the composite door 100.

[0080] In some embodiments, abutment connection members 180 are indirectly or directly attached to first composite edge connection member 120 and second composite edge connection member 122. Referring to FIG. 4C , in some embodiments, a portion of first composite stringer 130 and / or a portion of composite frame 110 is sandwiched between first composite edge connection member 120 and at least a first set of abutment connection members 180. Similarly, in some embodiments, a portion of second composite stringer 140 and / or a portion of composite frame 110 is sandwiched between second composite edge connection member 122 and at least a second set of abutment connection members 180.

[0081] 5 generally, and, for example, with reference to FIGS. 2-7 specifically, a method 300 for forming a composite door 100 is shown by way of example and not limitation. The method 300 includes cutting a prepreg sheet 400 to form a precursor frame sheet 410 having flaps 411 (block 310). The method 300 further includes draping the precursor frame sheet 410 along a door forming tool 500 (block 320). The door forming tool includes a frame surface 510 and flap supports 512 non-parallel to the frame surface 510, with each flap 411 of the precursor frame sheet 410 having a shape complementary to a corresponding one of the flap supports 512. The method 300 further includes forming the composite frame 110 by curing the frame precursor sheet 410 positioned along the door forming tool 500 (block 330), removing the composite frame 110 from the door forming tool 500 (block 340), and interconnecting the composite frame 110, the first composite edge connection member 120, the second composite edge connection member 122, the first composite stringer 130, the second composite stringer 140, and the composite skin 150 (block 350). The preceding description in this paragraph characterizes Example 25 of the present disclosure.

[0082] The various components of the composite door 100 are formed from prepreg sheets. Prepreg sheets allow for more precise control of material consistency than, for example, composite layup. For example, the composite frame 110 is formed from prepreg sheets 400 by cutting and molding the prepreg sheets into the shape of the composite frame 110. Furthermore, such prepreg sheets allow for the integral formation of distinct features, such as the various components of the composite frame 110. The composite door 100 is lighter than conventional doors, such as metal doors, and more specifically, aluminum doors. The composite door 100 is less susceptible to environmental degradation (e.g., corrosion) than conventional metal doors. Furthermore, the composite door 100 is comprised of fewer components than conventional doors, such as, for example, the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150.

[0083] The prepreg sheet 400 is cut to form a frame precursor sheet 410 having flaps 411. Next, the composite frame 110 is formed using the frame precursor sheet 410. Here, the flaps 411 correspond to the cross beams 113 of the composite frame 110. Specifically, the frame precursor sheet 410 is placed along a door forming tool 500 that defines the shape of the composite frame 110. For example, the door forming tool 500 includes a frame surface 510 and flap support portions 512 that are non-parallel to the frame surface 510. After the frame precursor sheet 410 is placed along the frame precursor sheet 410, each flap 411 of the sheet is brought into close contact with the corresponding flap support portion 512, forming complementary shapes. The shape of the flap support portion 512 corresponds to the shape of the cross beam 113.

[0084] The method 300 then proceeds to cure the frame precursor sheet 410 along the door forming tool 500, thereby forming the composite frame 110. In some embodiments, other components of the composite door 100 may be simultaneously cured in the door forming tool 500, for example, by being positioned along other portions of the door forming tool 500. The curing parameters are selected based on the properties (e.g., composition) of the prepreg sheet 400.

[0085] The composite door 100 is formed by interconnecting the composite frame 110, the first composite edge connection member 120, the second composite edge connection member 122, the first composite stringer 130, the second composite stringer 140, and the composite skin 150. The first composite stringer 130 and the second composite stringer 140 extend along the height of the composite door 100, for example, from the first skin edge 151 to the second skin edge 152 of the composite skin 150. In some embodiments, the first composite stringer 130 and the second composite stringer 140 extend parallel to each other. The first composite stringer 130 and the second composite stringer 140 support the composite skin 150 along its edges. In some embodiments, the first composite stringer 130 and the second composite stringer 140 are identical in shape and are interchangeable. For example, the first composite stringer 130 and the second composite stringer 140 have radii of curvature such that they are continuous with each other.

[0086] Each first composite edge connection member 120 interconnects a corresponding one of the cross beams 113 of the composite frame 110, a first composite stringer 130, and a composite skin panel 150. Similarly, each second composite edge connection member 122 interconnects a corresponding one of the cross beams 113, a second composite stringer 140, and a composite skin panel 150. The provision of the first composite edge connection members 120 and the second composite edge connection members 122 simplifies the design of the composite frame 110 while still providing a strong connection between the composite frame 110, the first composite stringer 130, and the composite skin panel 150. For example, each of the first composite edge connection members 120 and the second composite edge connection members 122 has multiple sides, as described below, making them well-designed to connect various components of the composite door 100.

[0087] 5 generally, and, for example, with reference to FIGS. 6A-6C specifically, by way of example and not limitation, in method 300, forming a frame precursor sheet 410 (block 310) includes forming closed contour cutouts 412 (block 312) in the frame precursor sheet 410. Each of the closed contour cutouts 412 defines the shape of a corresponding flap 411. The preceding description in this paragraph characterizes Example 26 of the present disclosure, which also encompasses Example 25 described above.

[0088] The flaps 411 are directly and integrally connected to the rest of the frame precursor sheet 410, but are partially separated from the frame precursor sheet 410 by closed contour cutouts 412. Being directly and integrally connected eliminates the need for additional attachment, thereby reducing the overall weight of the structure. The frame precursor sheet 410 is then used to form the composite frame 110. Each flap 411 of the frame precursor sheet 410 becomes a cross beam 113 of the composite frame 110. The closed contour cutouts 412 separate the flaps 411 from the portions of the frame precursor sheet 410 that will later become the first rail 111 and second rail 112 of the composite frame 110.

[0089] 5 generally, and, for example, with reference to Figures 6B and 6C specifically, by way of example and not limitation, in method 300, forming a closed contour cutout 412 (block 312) includes forming two parallel edge portions 414 and a central portion 413 connecting the two edge portions 414 (block 314). The preceding description in this paragraph characterizes Example 27 of the present disclosure, which also encompasses Example 26 described above.

[0090] The shape of the flaps 411, which will later become the cross beams 113 of the composite frame 110, is defined by the shape of the closed contour cutouts 412. The shapes of other components of the composite frame 110 that correspond to the flaps 411 are also defined by the shapes of the closed contour cutouts 412. The edges of each flap 411 are defined by a center portion 413. The flaps 411 are separated by two edge portions 414 from both end portions of the frame precursor sheet 410 from which the first rail 111 and the second rail 112 will later be formed. In some embodiments, the portions of the closed contour cutouts 412 are all formed by the same process, for example, by cutting the prepreg sheet 400.

[0091] 5 generally and, for example, with reference to FIGS. 7A-7E specifically, by way of example and not limitation, according to method 300, a door forming tool 500 has a skin surface 520. Method 300 further includes placing a skin prepreg sheet 420 along door forming tool 500 (block 360), such that skin prepreg sheet 420 has a shape complementary to skin surface 520. Method 300 further includes forming a composite skin 150 by curing skin prepreg sheet 420 along door forming tool 500 (block 364). The preceding description in this paragraph characterizes Example 28 of the present disclosure, which encompasses any of Examples 25-27 described above.

[0092] By using the door forming tool 500, multiple components of the composite door 100, for example, both the composite skin panel 150 and the composite frame 110, can be formed, eliminating the need for multiple tools. Specifically, the composite skin panel 150 is formed using a skin panel prepreg sheet 420, and the composite frame 110 is formed using a frame precursor sheet 410. When the skin panel prepreg sheet 420 is placed along the door forming tool 500, the skin panel prepreg sheet 420 is brought into close contact with the door forming tool 500, more specifically, with the skin panel surface 520. The skin panel surface 520 has the same shape as the composite skin panel 150.

[0093] 5 generally, and, for example, with reference to Figures 7A-7E specifically, by way of example and not limitation, in method 300, placing skin prepreg sheet 420 along door forming tool 500 (block 360) occurs with frame precursor sheet 410 already placed on door forming tool 500. The preceding description in this paragraph characterizes Example 29 of the present disclosure, which also encompasses Example 28 described above.

[0094] Door forming tool 500 can be used to form multiple components of composite door 100, such as composite skin 150 and composite frame 110, eliminating the need for multiple tools. Specifically, skin prepreg sheet 420 is used to form composite skin 150, and frame precursor sheet 410 is used to form composite frame 110. In some embodiments, these multiple components are formed simultaneously in door forming tool 500.

[0095] 5 generally, and, for example, with reference to Figures 7A-7E specifically, by way of example and not limitation, forming composite skin 150 (block 364) and forming composite frame 110 (block 330) occur simultaneously in method 300. The foregoing description in this paragraph characterizes Example 30 of the present disclosure, which encompasses either Example 28 or Example 29 described above.

[0096] The door forming tool 500 can be used to simultaneously form multiple components of the composite door 100, such as both the composite skin 150 and the composite frame 110. First, such simultaneous processing can reduce the overall processing time required to form all components of the composite door 100. Second, such simultaneous processing can eliminate the need for multiple tools. Specifically, the skin prepreg sheet 420 is used to form the composite skin 150, and the frame precursor sheet 410 is used to form the composite frame 110. In some embodiments, the same processing conditions (e.g., curing temperature and curing time) are used to form the composite skin 150 and the composite frame 110.

[0097] 5 generally, and, for example, with reference to FIGS. 7A, 7E, and 7F specifically, according to method 300, by way of example and not limitation, a door forming tool 500 has a first stringer surface 530 and a second stringer surface 540. Method 300 further includes placing a first stringer prepreg sheet 430 along the door forming tool 500 (block 370), such that the first stringer prepreg sheet 430 has a complementary shape to the first stringer surface 530. Method 300 further includes placing a second stringer prepreg sheet 440 along the door forming tool 500 (block 372), such that the second stringer prepreg sheet 440 has a complementary shape to the second stringer surface 540. The method further includes forming the first composite stringer 130 and the second composite stringer 140 by curing the first stringer prepreg sheet 430 and the second stringer prepreg sheet 440 arranged along the door forming tool 500 (block 374). The above description in this paragraph characterizes Example 31 of the present disclosure, which encompasses any of Examples 28 to 30 described above.

[0098] The door forming tool 500 can be used to form multiple components of the composite door 100, such as the composite skin 150, the first composite stringer 130, and the second composite stringer 140. First, such simultaneous processing reduces the overall processing time required to form all components of the composite door 100. Second, such simultaneous processing eliminates the need for multiple tools. Specifically, the skin prepreg sheet 420 is used to form the composite skin 150, the first stringer prepreg sheet 430 is used to form the first composite stringer 130, and the second stringer prepreg sheet 440 is used to form the second composite stringer 140.

[0099] When the first side girder prepreg sheet 430 is placed along the door forming tool 500, the first side girder prepreg sheet 430 is brought into close contact with the first side girder surface 530, as shown, for example, schematically in Fig. 7E. Similarly, when the second side girder prepreg sheet 440 is placed along the door forming tool 500, the second side girder prepreg sheet 440 is brought into close contact with the second side girder surface 540, as shown, for example, schematically in Fig. 7F.

[0100] 5 generally, and, for example, with reference to FIG. 7E specifically, by way of example and not limitation, in method 300, placing first stringer prepreg sheet 430 along door forming tool 500 (block 370) occurs with frame precursor sheet 410 already placed on door forming tool 500. The preceding description in this paragraph characterizes Example 32 of the present disclosure, which also encompasses Example 31 described above.

[0101] The door forming tool 500 can be used to form multiple components of the composite door 100, such as the composite skin 150, the first composite stringer 130, and the second composite stringer 140. First, such simultaneous processing can reduce the overall processing time required to form all components of the composite door 100. Second, such simultaneous processing can eliminate the need for multiple tools. Specifically, the skin prepreg sheet 420 is used to form the composite skin 150, the first stringer prepreg sheet 430 is used to form the first composite stringer 130, and the second stringer prepreg sheet 440 is used to form the second composite stringer 140. In some embodiments, these multiple components are formed simultaneously in the door forming tool 500.

[0102] 5 generally, and, for example, with reference to Figures 7E and 7F specifically, by way of example and not limitation, in method 300, forming first composite stringer 130 and second composite stringer 140 (block 374) and forming composite frame 110 (block 330) occur simultaneously. The preceding description in this paragraph characterizes Example 33 of the present disclosure, which encompasses either Example 31 or 32 described above.

[0103] The door forming tool 500 allows for the simultaneous formation of multiple components of the composite door 100, such as the composite skin 150, the composite frame 110, the first composite stringer 130, and the second composite stringer 140. First, such simultaneous processing reduces the overall processing time required to form all components of the composite door 100. Second, such simultaneous processing eliminates the need for multiple tools. Specifically, the composite skin 150 is formed using the skin prepreg sheet 420, the composite frame 110 is formed using the frame precursor sheet 410, the first composite stringer 130 is formed using the first stringer prepreg sheet 430, and the second composite stringer 140 is formed using the second stringer prepreg sheet 440. In some embodiments, the same processing conditions (e.g., curing temperature and curing time) are used to form the composite skin 150 and the composite frame 110.

[0104] 5 generally, and, for example, with reference to FIGS. 2F and 2G specifically, by way of example and not limitation, in method 300, interconnecting a composite frame 110, a first composite edge connection member 120, a second composite edge connection member 122, a first composite stringer 130, a second composite stringer 140, and a composite skin 150 (block 350) includes connecting the first composite stringer 130 to the composite frame 110 and connecting the second composite stringer 140 to the composite frame 110 (block 352). The preceding description in this paragraph characterizes Example 34 of the present disclosure, which encompasses any of Examples 25-33 described above.

[0105] Connecting the first composite stringer 130 and the second composite stringer 140 to the composite frame 110 increases the rigidity of the composite frame 110. Such connections allow the composite frame 110, the first composite stringer 130, and the second composite stringer 140 to be constructed using lighter structural materials.

[0106] In some embodiments, composite frame 110 directly interfaces with and overlaps first composite stringer 130, as shown in FIG. 2G. For example, composite frame 110 is disposed between one of first composite edge connecting members 120 and first composite stringer 130. In some embodiments, the connection between composite frame 110 and first composite stringer 130 is also interconnected to one of first composite edge connecting members 120.

[0107] Additionally, in some embodiments, composite frame 110 directly interfaces with and overlaps second composite stringer 140, as shown in FIG. 2F . For example, composite frame 110 is disposed between one of second composite edge connecting members 122 and second composite stringer 140. In some embodiments, the connection between composite frame 110 and second composite stringer 140 is also interconnected to one of second composite edge connecting members 122.

[0108] 5 generally, and, for example, with reference to FIG. 2G specifically, by way of example and not limitation, according to method 300, a first composite stringer 130 includes a first stringer base 131 and two first stringer side sections 132 non-parallel to the first stringer base 131. A composite frame 110 includes a first rail 111, a second rail 112, and a plurality of cross beams 113 connecting the first rail 111 and the second rail 112. Further, according to method 300, connecting the first composite stringer 130 to the composite frame 110 (block 352) includes connecting one of the two first stringer side sections 132 to the first rail 111 (block 354). The preceding description in this paragraph characterizes Example 35 of the present disclosure, which also encompasses Example 34 described above.

[0109] Connecting the first composite stringer 130 to the composite frame 110 increases the stiffness of the composite frame 110, particularly around the first rail 111. This connection allows the composite frame 110 and the first composite stringer 130, as well as other components, to be constructed using lighter structural materials.

[0110] In some embodiments, the first rail 111 of the composite frame 110 directly interfaces with and overlaps the first composite stringer 130, as shown in FIG. 2G. For example, the first rail 111 is disposed between one of the first composite edge connection members 120 (e.g., one of the two first side walls 124 of the corresponding first composite edge connection member) and the first composite stringer 130. In some embodiments, the connection between the first rail 111 and the first composite stringer 130 is also interconnected to one of the first composite edge connection members 120.

[0111] 5 generally, and, for example, with reference to FIG. 2F specifically, by way of example and not limitation, in method 300, interconnecting the composite frame 110, the first composite edge connection member 120, the second composite edge connection member 122, the first composite stringer 130, the second composite stringer 140, and the composite skin panel 150 (block 350) includes connecting the other of the two first stringer sides 132 of the first composite stringer 130 to the composite skin panel 150 (block 356). The preceding description in this paragraph characterizes Example 36 of the present disclosure, which also encompasses Example 35 described above.

[0112] Connecting the second composite stringer 140 to the composite frame 110 improves the stiffness of the composite frame 110, particularly around the second rail 112. This connection allows the composite frame 110 and the second composite stringer 140 to be constructed using lighter structural materials.

[0113] In some embodiments, the second rail 112 of the composite frame 110 directly interfaces with and overlaps the second composite stringer 140, as shown in FIG. 2F . For example, the second rail 112 is disposed between one of the second composite edge connection members 122 (e.g., one of the two second side walls 127 of the corresponding second composite edge connection member) and the second composite stringer 140. In some embodiments, the connection between the second rail 112 and the second composite stringer 140 is also interconnected to one of the second composite edge connection members 122.

[0114] 5 generally, and, for example, with reference to FIG. 2G specifically, by way of example only and not limitation, in method 300, interconnecting a composite frame 110, a first composite edge connection member 120, a second composite edge connection member 122, a first composite stringer 130, a second composite stringer 140, and a composite skin 150 (block 350) includes connecting a first stringer base portion 131 of the first composite stringer 130 to each first composite edge connection member 120 (block 357). The preceding description in this paragraph characterizes Example 37 of the present disclosure, which encompasses either Example 35 or 36 described above.

[0115] The connection of the first composite stringer 130 to the composite frame 110 improves the stiffness of the composite frame 110, particularly around the first rail 111 and around the composite skin panel 150 and first composite edge connection member 120. Furthermore, the first stringer base portion 131 provides spacing between the two first stringer side portions 132, thereby providing spacing between the first rail 111 and the composite skin panel 150, improving the mechanical strength of the composite door 100 as a whole. This connection allows the composite frame 110, first composite stringer 130, and composite skin panel 150 to be constructed using lighter structural materials.

[0116] 2G, the first stringer base portion 131 is a connecting portion between the two first stringer side portions 132. The two first stringer side portions 132 are non-parallel to the first stringer base portion 131. In some embodiments, for example, when the first rail 111 and the composite skin 150 of the portion opposite it are parallel, the two first stringer side portions 132 are parallel to each other.

[0117] 5 generally, and, for example, with reference to FIG. 2F specifically, by way of example and not limitation, in method 300, interconnecting a composite frame 110, a first composite edge connection member 120, a second composite edge connection member 122, a first composite stringer 130, a second composite stringer 140, and a composite skin panel 150 (block 350) includes connecting the composite frame 110 to the composite skin panel 150 (block 358). The preceding description in this paragraph characterizes Example 38 of the present disclosure, which encompasses any of Examples 25-34 described above.

[0118] The connection of the second composite stringer 140 to the composite frame 110 improves the stiffness of the composite frame 110, particularly around the second rail 112 and around the composite skin panel 150 and the second composite edge connecting member 122. Furthermore, the second stringer base portion 141 provides spacing between the two second stringer side portions 142, thereby providing spacing between the second rail 112 and the composite skin panel 150, improving the mechanical strength of the composite door 100 as a whole. This connection allows the composite frame 110, second composite stringer 140, second composite edge connecting member 122, and composite skin panel 150 to be constructed using lighter structural materials.

[0119] 2F, the second stringer base portion 141 is a connecting portion between the two second stringer side portions 142. The two second stringer side portions 142 are non-parallel to the second stringer base portion 141. In some embodiments, for example, when the second rail 112 and the composite skin 150 of the opposing portion are parallel, the two second stringer side portions 142 are parallel to each other.

[0120] 5 generally, and, for example, with reference to FIG. 3A specifically, by way of example and not limitation, according to method 300, composite frame 110 includes a first rail 111, a second rail 112, and a plurality of cross beams 113 connecting first rail 111 and second rail 112. Each cross beam 113 of composite frame 110 has a main portion 114 that extends non-parallel to first rail 111 and second rail 112 to a composite skin 150. Each cross beam 113 of composite frame 110 further includes a skin support portion 115 that extends non-parallel from the main portion 114 of the cross beam 113. Additionally, in method 300, connecting composite frame 110 to composite skin 150 (block 358) includes connecting the skin support portion 115 of each cross beam 113 to composite skin 150 (block 359). The preceding statements in this paragraph characterize Example 39 of the present disclosure, which also encompasses Example 38 described above.

[0121] The skin support portion 115 is a portion that forms an interface with the composite skin 150 when the composite skin 150 is attached to the composite frame 110, and is also a portion that supports the composite skin 150, for example, between the first composite stringer 130 and the second composite stringer 140. By attaching and supporting as described above, the composite skin 150 that can withstand a critical load (for example, a pressure difference on both sides of the composite skin 150) can be made of a lightweight material.

[0122] In some embodiments, each skin support 115 conforms to the shape of the opposing composite skin 150, thereby defining a bonded interface between the composite skin 150 and the composite frame 110. The skin support 115 extends between the first composite stringer 130 and the second composite stringer 140, or at least between the first composite edge connection member 120 and the second composite edge connection member 122.

[0123] 5 generally, and, for example, with reference to FIG. 3A specifically, by way of example and not limitation, in method 300, interconnecting a composite frame 110, a first composite edge connection member 120, a second composite edge connection member 122, a first composite stringer 130, a second composite stringer 140, and a composite skin panel 150 (block 350) includes connecting each first composite edge connection member 120 to the composite frame 110, the first composite stringer 130, and the composite skin panel 150 (block 351), and further includes connecting each second composite edge connection member 122 to the composite frame 110, the second composite stringer 140, and the composite skin panel 150 (block 353). The preceding description in this paragraph characterizes Example 40 of the present disclosure, which encompasses any of Examples 25-34 described above.

[0124] The first composite edge connecting member 120 and the second composite edge connecting member 122 enable interconnection of multiple components of the composite door 100, such as, for example, the composite frame 110, the first composite stringer 130, the second composite stringer 140, and the composite skin 150. Specifically, the first composite edge connecting member 120 and the second composite edge connecting member 122 ensure load transfer between these components.

[0125] 5 generally, and, for example, FIG. 2G specifically, by way of example and not limitation, according to method 300, a first composite stringer 130 has a first stringer base portion 131 and two first stringer side portions 132 non-parallel to the first stringer base portion 131. Additionally, in method 300, connecting each first composite edge connection member 120 to the composite frame 110, the first composite stringer 130, and the composite skin 150 (block 351) includes connecting each first composite edge connection member 120 to the first stringer base portion 131 of the first composite stringer 130 (block 355). The preceding description in this paragraph characterizes Example 41 of the present disclosure, which also encompasses Example 40 described above.

[0126] The connection of the first composite stringer 130 to the composite frame 110 improves the stiffness of the composite frame 110, particularly around the first rail 111 and around the composite skin panel 150 and first composite edge connection member 120. Furthermore, the first stringer base portion 131 provides spacing between the two first stringer side portions 132, thereby providing spacing between the first rail 111 and the composite skin panel 150, improving the mechanical strength of the composite door 100 as a whole. This connection allows the composite frame 110, first composite stringer 130, and composite skin panel 150 to be constructed using lighter structural materials.

[0127] 2G, the first stringer base portion 131 is a connecting portion between the two first stringer side portions 132. The two first stringer side portions 132 are non-parallel to the first stringer base portion 131. In some embodiments, for example, when the first rail 111 and the composite skin 150 of the portion opposite it are parallel, the two first stringer side portions 132 are parallel to each other.

[0128] 5 generally, and, for example, with reference to FIGS. 2H and 2I specifically, by way of example and not limitation, according to method 300, composite frame 110 includes first rail 111, second rail 112, and a plurality of cross beams 113 connecting first rail 111 and second rail 112. Each cross beam 113 of composite frame 110 has a main portion 114 that extends to composite skin panel 150 in a direction non-parallel to first rail 111 and second rail 112. Additionally, in method 300, connecting each first composite edge connection member 120 to composite frame 110, first composite stringer 130, and composite skin panel 150 (block 351) includes connecting each first composite edge connection member 120 to the main portion 114 of a corresponding one of the cross beams 113 (block 380). The foregoing in this paragraph characterizes Example 42 of the presently disclosed subject matter, which also encompasses Example 40 described above.

[0129] The different walls of the first composite edge connecting member 120 allow multiple components of the composite door 100 to be connected to one another. For example, the combination of the side and bottom walls of the first composite edge connecting member 120 can provide a strong connection to the composite frame 110, which is one of the main structural components of the composite door 100. In particular, each first composite edge connecting member 120 supports the portion of the composite frame 110 facing the connecting member, thereby improving the strength of each component of the composite frame 110 (e.g., the main section 114). Using the first composite edge connecting member 120 to connect components in this manner facilitates the design and manufacture of other components of the composite door 100. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0130] 5 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, according to method 300, each first composite edge connection member 120 has a first bottom wall 123, two first side walls 124, and a first end wall 125. The two first side walls 124 are interconnected by the first bottom wall 123 and the first end wall 125. Additionally, in method 300, connecting each first composite edge connection member 120 to the composite frame 110, the first composite stringer 130, and the composite skin 150 (block 351) includes connecting the first bottom wall 123 and one of the two first side walls 124 of each first composite edge connection member 120 to a corresponding one of the cross beams 113 (block 381). The preceding description in this paragraph characterizes Example 43 of the present disclosure, which also encompasses Example 42 described above.

[0131] The multiple walls of the first composite edge connecting member 120 (e.g., the first bottom wall 123, the two first side walls 124, and the first end wall 125) allow multiple components of the composite door 100 to be interconnected. This connection using the first composite edge connecting member 120 facilitates the design and manufacture of other components of the composite door 100.

[0132] In some embodiments, one of the two first side walls 124 is connected to a cross beam 113 of the composite frame 110, as shown in FIG. 2H. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0133] Similarly, each second composite edge connecting member 122 has a second bottom wall 126, two second side walls 127, and a second end wall 128. These multiple walls of the second composite edge connecting members 122 allow multiple components of the composite door 100 to be interconnected. Using the second composite edge connecting members 122 in this manner facilitates the design and manufacture of other components of the composite door 100.

[0134] 5 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, in method 300, connecting each first composite edge connection member 120 to the composite frame 110, the first composite stringer 130, and the composite skin panel 150 (block 351) includes connecting the other of the two first side walls 124 of each first composite edge connection member 120 to the composite skin panel 150 (block 382). The preceding description in this paragraph characterizes Example 44 of the present disclosure, which also encompasses Example 43 described above.

[0135] The multiple walls of the first composite edge connecting member 120 allow multiple components of the composite door 100 to be connected to one another. For example, the combination of the two first side walls 124 of the first composite edge connecting member 120 connects the composite skin panel 150 to the composite frame 110. In particular, each first composite edge connecting member 120 supports the portion of the composite skin panel 150 facing the connecting member relative to the composite frame 110, thereby improving the strength of the composite skin panel 150. The use of the first composite edge connecting member 120 in this manner facilitates the design and manufacture of other components of the composite door 100. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0136] 5 generally, and, for example, with reference to FIG. 2H specifically, by way of example and not limitation, in method 300, connecting each first composite edge connection member 120 to the composite frame 110, the first composite stringer 130, and the composite skin 150 (block 351) includes connecting the first end wall 125 of each first composite edge connection member 120 to the first composite stringer 130 (block 383). The preceding description in this paragraph characterizes Example 45 of the present disclosure, which also encompasses Example 44 described above.

[0137] The multiple walls of the first composite edge connecting member 120 allow multiple components of the composite door 100 to be connected to one another. For example, the combination of the two first side walls 124 and the first end wall 125 of the first composite edge connecting member 120 connects the first composite stringer 130 and the composite frame 110 to one another. In particular, each first composite edge connecting member 120 supports the corresponding portion of the composite frame 110 and the composite skin 150 relative to the first composite stringer 130, thereby improving the strength of each component at the joint interface. Using the first composite edge connecting member 120 in this manner facilitates the design and manufacture of other components of the composite door 100. This connection can be formed by various means, such as adhesives, fasteners, etc., as described below.

[0138] 5 generally, and, for example, with reference to Figures 8 and 9 specifically, by way of example only and not limitation, in method 300, interconnecting a composite frame 110, a first composite edge connection member 120, a second composite edge connection member 122, a first composite stringer 130, a second composite stringer 140, and a composite skin panel 150 (block 350) includes interconnecting the composite frame 110, the first composite edge connection member 120, the second composite edge connection member 122, the first composite stringer 130, the second composite stringer 140, and the composite skin panel 150 with fasteners 190 (block 384). The preceding description in this paragraph characterizes Example 46 of the present disclosure, which encompasses either Example 44 or 45 described above.

[0139] Fasteners 190 may be used to interconnect various components of composite door 100 and to transfer loads between these components, such as between composite panel 150 and stringer 113, between composite panel 150 and first composite stringer 130, and between composite panel 150 and second composite stringer 140. Additionally, fasteners 190 may be used to interconnect components made of different types of materials, such as composite and metal. Examples of fasteners 190 include, but are not limited to, rivets, bolt and nut connections, etc.

[0140] 5 generally, and, for example, with reference to Figures 8 and 9 specifically, by way of example only and not limitation, in method 300, interconnecting a composite frame 110, a first composite edge connection member 120, a second composite edge connection member 122, a first composite stringer 130, a second composite stringer 140, and a composite skin panel 150 (Block 350) includes interconnecting the composite frame 110, the first composite edge connection member 120, the second composite edge connection member 122, the first composite stringer 130, the second composite stringer 140, and the composite skin panel 150 with an adhesive 192 (Block 385). The preceding description in this paragraph characterizes Example 47 of the present disclosure, which encompasses any of Examples 44-46 described above.

[0141] The adhesive 192 allows for interconnection and load transfer between the various components of the composite door 100 without requiring the creation of holes or other irregularities in the components. Additionally, the adhesive 192 typically weighs less than other types of fasteners, which is important in various applications, such as aircraft. Referring to FIG. 2K, adhesive 192 is applied between the composite skin 150 and each of the stringers 113, connecting the composite skin 150 to each of the stringers 113. Adhesive 192 is also applied between the composite skin 150 and the first composite stringer 130, for example, along the entire length of the first composite stringer 130. Adhesive 192 is also applied between the composite skin 150 and the second composite stringer 140, for example, along the entire length of the second composite stringer 140.

[0142] An embodiment of the disclosure may be described with reference to an aircraft manufacturing and service method 1100 shown in FIG. 8 and an aircraft 1102 shown in FIG. 9 . As a pre-production step, the aircraft manufacturing and service method 1100 includes specification and design of the aircraft 1102 (block 1104) and material procurement (block 1106). During production, component and subassembly manufacturing (block 1108) and system integration (block 1110) of the aircraft 1102 occurs. The aircraft 1102 then undergoes, for example, certification and delivery (block 1112) and enters service (block 1114). While in service, the aircraft 1102 undergoes a schedule of routine maintenance and upkeep (block 1116). Routine maintenance and upkeep may also include modification, reconfiguration, retrofitting, or the like, of one or more systems of the aircraft 1102.

[0143] Each step of method 1100 may be performed or implemented by a system integrator, a third party, and / or an operator (e.g., a customer). Note that a system integrator may include, but is not limited to, any number of aircraft manufacturers and major system subcontractors. A third party may include, but is not limited to, any number of vendors, subcontractors, and suppliers. An operator may be an airline, a leasing company, a military entity, a service organization, etc.

[0144] 9 , an aircraft 1102 produced by exemplary method 1100 includes an airframe 1118 with a plurality of high-level systems 1120 and an interior 1122. Examples of the plurality of high-level systems 1120 include one or more of a propulsion system 1124, an electrical system 1126, a hydraulic system 1128, and an environmental system 1130. Any number of other systems may also be included. While an aerospace example has been described, the principles of the present disclosure may be applied to other industries, such as the automotive industry. Thus, in addition to the aircraft 1102, the principles of the present disclosure may be applied to other vehicles, such as land vehicles, watercraft, and spacecraft.

[0145] The apparatus and methods described or illustrated herein may be employed in one or more of the steps of method of manufacturing and use 1100. For example, the parts or subassemblies produced in part and subassembly manufacturing (block 1108) may be similarly constructed or manufactured to the parts or subassemblies produced while the aircraft 1102 is in service (block 1114). Also, one or more of the apparatus embodiments, method embodiments, or a combination thereof may be employed in manufacturing steps 1108 and 1110. This may, for example, significantly expedite or significantly reduce the cost of assembly of the aircraft 1102. Similarly, one or more apparatus or method embodiments, or a combination thereof, may be used, without limitation, while the aircraft 1102 is in service (block 1114) and / or during maintenance and service (block 1116).

[0146] Various embodiments of the apparatus and methods of the present disclosure include various components, features, and functions, and various embodiments of the apparatus and methods of the present disclosure may include any of the components, features, and functions of any other embodiment of the apparatus and methods of the present disclosure, in any combination.

[0147] Many variations on the above-described embodiments will be apparent to one skilled in the art based on the teachings presented in the above description and accompanying drawings.

[0148] Accordingly, it is to be understood that the subject matter of the present disclosure is not limited to the particular embodiments described, and that modifications and other embodiments are intended to be encompassed within the scope of the appended claims. Moreover, while the above description and associated drawings describe embodiments of the subject matter of the present disclosure in connection with specific exemplary combinations of elements and / or functions, alternative implementations may provide different combinations of elements and / or functions without departing from the scope of the appended claims. Accordingly, where reference numerals in parentheses appear in the appended claims, these are for illustrative purposes only and are not intended to limit the scope of the claimed subject matter to the particular embodiments of the present disclosure.

Claims

1. a composite frame including a first rail, a second rail, and a crossbeam connecting the first rail and the second rail; a first composite stringer; and a second composite stringer; and a composite skin connected to each of the cross beams of the composite frame, the first composite stringer, and the second composite stringer; first composite edge connection members, each connected to a corresponding one of the cross beams of the composite frame, the first composite stringer, and the composite skin; a composite door comprising: second composite edge connection members, each connected to a corresponding one of the stringers of the composite frame, the second composite stringer, and the composite skin; Each first composite edge connecting member includes a bottom wall, two side walls that stand up from the bottom wall and are spaced apart from each other, and an end wall that stands up from the bottom wall and connects the two side walls, A composite door, wherein one of the two side walls and the bottom wall are connected to a corresponding one of the stringers, and the end wall is connected to the first composite stringer.

2. the first composite stringer is connected to the first rail of the composite frame; The composite door of claim 1 , wherein the second composite stringer is connected to the second rail of the composite frame.

3. a composite frame including a first rail, a second rail, and a crossbeam connecting the first rail and the second rail; a first composite stringer; and a second composite stringer; and a composite skin connected to each of the cross beams of the composite frame, the first composite stringer, and the second composite stringer; first composite edge connection members, each connected to a corresponding one of the cross beams of the composite frame, the first composite stringer, and the composite skin; a composite door comprising: second composite edge connection members, each connected to a corresponding one of the stringers of the composite frame, the second composite stringer, and the composite skin; the first composite stringer includes a first stringer base portion and two first stringer side portions non-parallel to the first stringer base portion; the first stringer base portion is connected to each of the first composite edge connecting members; one of the two first stringer side portions is connected to the first rail of the composite frame; a composite door, wherein the other of the two first stringer side portions is connected to the composite skin.

4. a composite frame including a first rail, a second rail, and a crossbeam connecting the first rail and the second rail; a first composite stringer; and a second composite stringer; and a composite skin connected to each of the cross beams of the composite frame, the first composite stringer, and the second composite stringer; first composite edge connection members, each connected to a corresponding one of the cross beams of the composite frame, the first composite stringer, and the composite skin; a composite door comprising: second composite edge connection members, each connected to a corresponding one of the stringers of the composite frame, the second composite stringer, and the composite skin; The second composite stringer includes a second stringer base portion and two second stringer side portions non-parallel to the second stringer base portion. the second stringer base portion is connected to each of the second composite edge connecting members; one of the two second stringer side portions is connected to the second rail of the composite frame; a composite door, wherein the other of the two second stringer side portions is connected to the composite skin.

5. The composite door of any one of claims 1 to 4, wherein the cross beam of the composite frame includes a main portion that extends to the composite skin non-parallel to the first rail and the second rail.

6. 6. The composite door of claim 5, wherein the main portion of the crossbeam extends between each of the first rail and the second rail and the composite skin.

7. the cross beam of the composite frame further includes skin support portions, each of the skin support portions extending non-parallel from a corresponding one of the main portions of the cross beam; 7. The composite door of claim 5 or 6, wherein each of the skin supports of the cross beam is connected to the composite skin.

8. 8. The composite door of claim 7, wherein each of the skin support portions of the crossbeam extends along the composite skin from a corresponding one of the main portions of the crossbeam.

9. the skin support portion of the cross beam includes a first skin support portion and a second skin support portion, Each of the first skin supports is connected to a corresponding one of the main sections of the cross beam. extending in a first direction along the skin; 9. The composite door of claim 7 or 8, wherein each of the second skin support portions extends from a corresponding one of the main portions of the cross beam along the composite skin in a second direction opposite to the first direction.

10. The composite door of any one of claims 1 to 9, wherein each of the first rail and the second rail is parallel to the composite skin.

11. 1. A method of forming a composite door, comprising: forming a frame precursor sheet having flaps by cutting a prepreg sheet; placing the frame precursor sheet along a door forming tool, the door forming tool including a frame surface and flap support portions non-parallel to the frame surface, thereby forming each of the flaps of the frame precursor sheet into a shape complementary to a corresponding one of the flap support portions; forming a composite frame by curing the frame precursor sheet positioned along the door forming tool; removing the composite frame from the door forming tool; interconnecting the composite frame, a first composite edge connection member, a second composite edge connection member, a first composite stringer, a second composite stringer, and a composite skin.

12. the step of forming the frame precursor sheet includes a step of forming a closed contour notch in the frame precursor sheet; The method of claim 11 , wherein each of the flaps is defined by a corresponding one of the closed contour cutouts.

13. The step of forming the closed contour notch includes: forming two edge portions extending parallel to each other; and forming a central portion extending between and joining the two edge portions.

14. The door forming tool has a skin surface, and the method further comprises: placing a skin prepreg sheet along the door forming tool to form the skin prepreg sheet into a shape complementary to the skin surface; and forming the composite skin by curing the skin prepreg sheet positioned along the door forming tool.

15. The method of claim 14, wherein the step of placing the skin prepreg sheet along the door forming tool is performed with the frame precursor sheet already placed on the door forming tool.

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