Stiffener for an aircraft component

Abstract

The present application relates to a stiffener for an aircraft component. The stiffener provides structural stability for the aircraft component. The stiffener has a first stiffener member and a second stiffener member, the first stiffener member having a planar web portion, and the second stiffener member being arranged together with the first stiffener member. The second stiffener member includes a corrugated web portion having corrugations. The present application also relates to an aircraft component, an aircraft fuselage, an aircraft, and a method of forming a stiffener for an aircraft component.

Description

Technical Field

[0001] The present invention relates to stiffeners for aircraft components. In particular, the present invention relates to stiffeners for providing structural stability to aircraft components. The present invention also relates to aircraft components, the fuselage of an aircraft, an aircraft, and a method of forming a stiffener for an aircraft component. Background Art

[0002] The fuselage structure of an aircraft includes panels that serve as the fuselage skin, stringers that extend longitudinally along the fuselage, and stiffeners or frames that extend perpendicular to the stringers. The stringers and stiffeners are fixed to the skin to provide structural support. The frames are typically in a circular configuration of C-shaped, L-shaped, or Z-shaped.

[0003] Stiffeners are typically integral stiffeners or frames, i.e., the frames are fixed to the skin, or differential stiffeners or frames, i.e., the frames are fixed to the skin at spaced intervals. In the case of a differential frame, clips mount the frame to the skin between the stringers. Splints are used to connect the frame to the stringers, particularly to prevent the frame from bending due to lateral torsional deformation when the frame is subjected to mechanical stress. In the case of an integral frame, the frame is directly fixed to the skin, and openings formed in the frame receive the stringers in such a way that the stringers pass through the openings. Stabilizers are provided at the openings to provide lateral stability.

[0004] The use of a number of components including clips, splints, and stabilizers results in a complex assembly. Thus, the complexity in the form of these parts involves significant costs. Assembling these clips, splints, and stabilizers is a complex and time-consuming process. Summary of the Invention

[0005] According to one aspect of the present invention, there is provided a stiffener for an aircraft component, the stiffener comprising: a first stiffener member having a planar web portion that is planar along a longitudinal direction of the first stiffener member; and a second stiffener member arranged together with the first stiffener member, wherein the second stiffener member includes a corrugated web portion having corrugations.

[0006] Advantageously, the planar web portion provides stability in the normal direction, i.e., along the longitudinal axis of the stiffener, and the corrugated web portion provides additional stability in another direction. In this arrangement, the stiffness of the stiffener is provided in the normal direction, lateral direction, and transverse direction, and thus, the need for auxiliary clips, splints, and stabilizers is minimized or eliminated. In addition, the weight of the stiffener assembly for the required stiffness can be minimized.

[0007] The corrugated portion may extend transversely to the longitudinal axis of the planar web portion. Thereby, additional lateral stability is provided.

[0008] The stiffener may include a plurality of corrugated portions spaced along the longitudinal length of the web.

[0009] In such an arrangement, the required stiffness can be provided along the length of the web. The complexity of manufacturing the stiffener can be minimized.

[0010] The stiffener may include a core disposed within the corrugated portion and between the planar web portion and the corrugated web portion.

[0011] Advantageously, the core provides additional stability to the stiffener.

[0012] The core may be sandwiched between the planar web portion and the corrugated web portion.

[0013] The core may include a polymer block. Preferably, the block is made of Nomex material. Preferably, the block is formed of one or more of PVC foam and polyurethane foam.

[0014] The core may include columnar portions.

[0015] The planar web portion and the corrugated web portion may form a web, and the stiffener may include feet extending from the web.

[0016] The core may extend from the feet to the free end of the stiffener.

[0017] At least one of the first stiffener member and the second stiffener member may overlap the core at the free end.

[0018] The stiffener may include a prepreg layer located between the planar web portion and the corrugated web portion.

[0019] The first stiffener member may have at least one of a C-shaped, L-shaped, and Z-shaped configuration. The second stiffener member may have at least one of a C-shaped, L-shaped, and Z-shaped configuration. The stiffener may have at least one of a C-shaped, L-shaped, I-shaped, Z-shaped, and J-shaped configuration.

[0020] The stiffener may include an opening configured to receive a spar between the corrugated portions or between each pair of corrugated portions.

[0021] According to one aspect of the present invention, there is provided a stiffener for an aircraft component, the stiffener including: a stiffener member having a planar web portion and feet, the planar web portion being planar along the longitudinal direction of the first stiffener member; and a block extending transversely to the longitudinal direction of the stiffener member between the feet and the free end.

[0022] The stiffener can be a frame for an aircraft fuselage.

[0023] According to one aspect of the present invention, there is provided an aircraft component including a panel, a spar, and a stiffener as set forth above.

[0024] The spar can be configured to extend through the stiffener, and the stiffener can be configured to be mounted to the panel.

[0025] The spar can be configured to be disposed between the stiffener and the panel, and the stiffener can be configured to be mounted to the spar.

[0026] The aircraft component can include a stabilizer configured to be mounted between the panel and the stiffener.

[0027] According to one aspect of the present invention, there is provided an aircraft fuselage including a stiffener as set forth above.

[0028] According to one aspect of the present invention, there is provided an aircraft fuselage including an aircraft component as set forth above.

[0029] According to one aspect of the present invention, there is provided a method of forming a stiffener for an aircraft component, the method including: holding a first stiffener member having a planar web portion, wherein the planar web portion is planar in a longitudinal direction of the first stiffener member; holding a second stiffener member having a corrugated web portion, wherein the corrugated web portion includes corrugations; disposing a core within the corrugations; and sandwiching the core between the first stiffener member and the second stiffener member.

[0030] According to one aspect of the present invention, there is provided a stiffener for an aircraft component, the stiffener including: a first stiffener member having a planar web portion; and a second stiffener member disposed together with the first stiffener member. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Embodiments of the present invention will now be described with reference to the drawings, in which:

[0032] Figure 1 is a plan view of an aircraft having a fuselage mechanism;

[0033] Figure 2 is a perspective view showing a known configuration of a part of the fuselage mechanism;

[0034] Figure 3 is a perspective view showing Figure 2 the known configuration of the part of the fuselage mechanism of

[0035] Figure 4 is a perspective view of another known configuration showing a part of the fuselage mechanism;

[0036] Figure 5 is a front view of another known configuration showing a part of the fuselage mechanism;

[0037] Figure 6 is a perspective view of a part of the fuselage structure according to the present invention;

[0038] Figure 7 is at Figure 6 is a cross-sectional perspective view of the stiffener of the fuselage support shown in, passing through the extended area;

[0039] Figure 8 is a cross-sectional perspective view of an alternative stiffener passing through the extended area;

[0040] Figure 9 is a perspective view of an alternative arrangement of a part of the fuselage mechanism according to the present invention;

[0041] Figure 10 is Figure 9 is a perspective view of the arrangement of the part of the fuselage mechanism shown in;

[0042] Figure 11 is Figure 10 is a perspective view of the arrangement of the part of the fuselage mechanism shown in; and Figures 12a to 12d shows a method of forming a stiffener for a fuselage support of an aircraft. DETAILED DESCRIPTION

[0043] In Figure 1 an aircraft 10 is shown. The aircraft 10 includes a fuselage 11. Two wings 12 extend from the fuselage 11. It will be understood that the fuselage 11 and the wings 12 may take various different planar shapes and configurations depending on the particular application. The fuselage 11 defines a longitudinal axis 13. The longitudinal axis 13 extends from a front end 14 to a rear end 15. Each wing 12 includes a wing box. The wing box forms the body of the wing 12.

[0044] In the following description, the term "front" refers to a component towards the leading edge of the wing, and the term "rear" refers to a component towards the trailing edge of the wing. The terms "forward" and "backward" should be interpreted accordingly. The position of a feature may be interpreted relative to other components, for example, a forward component may be arranged on the front side of another component but towards the rear of the wing.

[0045] The fuselage 11 includes a fuselage mechanism 20. The fuselage mechanism 20 is generally tubular. The fuselage mechanism 20 extends along the longitudinal axis 13. The fuselage mechanism 20 may be formed by a plurality of assembled parts.

[0046] Reference Figures 2 to 4 , shows a known arrangement of the fuselage structure. Figure 2 and Figure 3 shows a known arrangement of the fuselage structure known as an integral frame configuration, and Figure 4 and Figure 5 shows another known arrangement of the fuselage mechanism known as a differential frame configuration.

[0047] The fuselage mechanism 20 includes a panel 21. The panel 21 serves as the fuselage skin. The panel 21 is curved. The panel 21 has an outer side 22 and an inner side 23. The panel 21 is formed of a composite material, a metallic material, or a combination of a composite material and a metallic material. The fuselage mechanism 20 includes stringers 30 and stiffeners 40 also known as frames. The stiffeners 40 extend perpendicular to the stringers 30. The stringers 30 and the stiffeners 40 are fixed to the skin to provide structural support.

[0048] The stringers 30 extend along the inner side 23 of the panel 21. The stringers 30 extend longitudinally along the fuselage 11. The stringers 30 are elongated members. The stringers 30 have a U-shaped configuration as shown in Figure 2 and Figure 3 . This configuration is referred to as a "top hat" stringer arrangement. Each of the stringers 30 has at least one stringer foot 31. The stringer foot or each stringer foot 31 is mounted to the panel 21. In Figure 2 and Figure 3 , each stringer 30 has two stringer feet 31. In Figure 4 and Figure 5 , each stringer has one stringer foot 31. Each of the stringers 30 has an upright portion 32 protruding from the panel 21. The upright portion 32 is formed by at least one stringer web 33 extending from the at least one stringer foot 31. Each stringer 30 has two stringer webs 33 and has a flange 34 at the free end. The flange extends between the stringer webs 33. The stringer 30 has an extended flange portion 35. The extended flange portion 35 extends perpendicular to the longitudinal axis of the stringer 30. The extended flange portion 35 extends from the stringer foot 31. In Figure 2 and Figure 3 , the stiffeners 40 are positioned on the extended flange portion 35. The extended flange portion 35 extends parallel to the longitudinal axis of each stiffener 40.

[0049] The stiffeners 40 also known as frames extend on the inner side 23 of the panel 21. The stiffeners 40 are indirectly mounted to the panel 21. The stiffeners 40 are mounted to the stringers 30. The stiffeners 40 extend perpendicular to the longitudinal axis of the fuselage 11. The stiffeners 40 extend in a circumferential arrangement. Thus, the stiffeners are curved.

[0050] In Figure 2 and Figure 3In [description], a one-piece frame configuration is shown. The stiffener 40 is fixed to the panel 21, for example, by bolting or bonding. The stiffener 40 has a C-shaped configuration as shown in Figure 2 and Figure 3 . The stiffener 40 has a stiffener foot 41, a stiffener web 42, and a stiffener flange 43. An opening 44 is formed through the stiffener 40. The opening 44 extends from the lower end of the stiffener 40, and the opening 44 is referred to as a "rat hole". The opening 44 divides the stiffener foot 41 into multiple stiffener foot portions 45. The openings 44 are spaced along the longitudinal length of the stiffener 40. The spacing of the openings 44 corresponds to the spacing of the stringers 30 on the panel 21. When assembling, the stringers 30 are received in the openings 44. The rib foot 41 is mounted to the panel 21. The rib foot 41 is mounted to the panel 21 via the extending flange portion 35.

[0051] The stabilizer 50 extends from the panel 21 to the stiffener 40. The stabilizer 50 extends at an arcuate angle between the stringer foot 31 and the stiffener web 42 and / or between the inner side 23 of the panel 21 and the stiffener web 42. The stabilizer 50 provides lateral stability to the stiffener 40.

[0052] In Figure 4 and Figure 5 , a differential frame configuration is shown. The stiffener 40 is spaced from the panel 21 by the stringer 30. That is, the stiffener 40 is arranged at opposite ends of the stringer web 33. Each stiffener 40 has a Z-shaped configuration as shown in Figure 4 and Figure 5 . The stiffener 40 is fixed to at least one of the stringer flange 34 and the clip 51, for example, by bolting or bonding. The clip 51 mounts the stiffener 40 to the panel 21. The splint 52 extends between the panel 21 and the stiffener 40. The splint 52 provides lateral stability to the stiffener 40. One clip and one splint are arranged between a pair of adjacent stringers 30. In the current arrangement, the one clip 51 and the splint 52 in each gap between adjacent stringers 30 are integrally formed. It will be understood that the clip 51 and the splint 52 can be formed separately. Each clip extends substantially across the gap between adjacent stringers 30.

[0053] In the arrangement shown in Figure 4 , the stiffener 40 abuts against the stringer flange 34. In the arrangement shown in Figure 5 , the stiffener 40 is spaced from the stringer.

[0054] As shown in Figures 6 to 11 , the embodiments of the present invention will now be described. The arrangement of the panel 21 and the stringers 30 is generally the same as that referred to above with reference to Figures 2 to 5The described arrangement is the same, and thus, a detailed description will be omitted. However, the extended flange portion is omitted. In an alternative embodiment, there is an extended flange portion. In various embodiments of the present invention, the configuration of the stiffeners is different. The stiffeners according to the various embodiments described herein have a self-supporting arrangement. The panel 21 and the stiffeners 70 are formed of composite material layers, although the constitution and materials of the panel and the stiffeners may be different.

[0055] In Figure 6 a, an integral frame configuration is shown. The fuselage mechanism 20 includes a panel 21 and stringers 30 generally as described above. However, the fuselage mechanism 20 is shown to have stringers 30 of a T-shaped configuration, the T-shaped stringers 30 having stringer feet 31 extending from each side of the stringer web 33. It will be understood that the configuration of the stringers 30 can be changed. Stringers of different configurations can be arranged on the panel 21. Alternatively, for example, the stringers can have a T-shaped, U-shaped, Z-shaped, L-shaped or I-shaped configuration.

[0056] In Figure 6 a, a stiffener or frame 70 is shown. It will be understood that the number of stiffeners 70 can be changed. The stiffeners 70 extend perpendicular to the stringers 30. Adjacent stiffeners 70 are spaced apart from each other. The stiffeners 70 have a J-shaped configuration. The shape of the frame can be changed. The stiffeners 70 can have, for example, a C-shaped, L-shaped or Z-shaped configuration. The stiffeners 70 extend on the inner side 23 of the panel 21. The stiffeners 70 are directly mounted to the panel 21 and the stringers 30. The stiffeners 70 extend perpendicular to the longitudinal axis of the fuselage 11. The stiffeners 70 extend in a circumferential arrangement. Thus, the stiffeners are arcuate. The stiffeners are formed of composite material layers, although the constitution and materials of the stiffeners may be different.

[0057] The stiffeners 70 are fixed to the panel 21, for example, by bolt connection or bonding. The stiffeners 70 have stiffener feet 71 extending from each side of the stiffener web 72. In the current embodiment, each stiffener foot 71 is directly fixed to the inner side 23 of the panel 21. In an alternative embodiment having an extended flange portion extending from the stringers 30, the stiffener feet 71 are fixed to the panel 21 via the stringers 30. The stiffener flange 73 is at the free end of the stiffener web 72 spaced from the stiffener feet 71. The stiffener flange 73 extends perpendicularly from the stiffener web 72. The stiffener feet 71 and the stiffener flange 73 extend perpendicular to the stiffener web 72. This arrangement can be changed. For example, in the case of a C-shaped or Z-shaped configuration, each stiffener 70 has a stiffener foot 71 extending only from one side of the stiffener web 72.

[0058] The opening 74 is formed through the stiffener 70. The opening 74 extends from the lower end portion of the stiffener 70, and the opening 74 is referred to as a "mousehole". The opening 74 divides the stiffener foot 71 into a plurality of stiffener foot portions 75. The openings 74 are spaced along the longitudinal length of the stiffener 70. The spacing of the openings 74 corresponds to the spacing of the stringers 30 on the panel 21. When assembling, the stringers 30 are received in the openings 74. The stiffener foot 71 is mounted to the panel 21. The stiffener foot 74 is attached to the panel 21.

[0059] The stiffener 70 has an extension portion 76. The extension portions 76 are spaced along each stiffener 70. Three extension portions 76 can be seen in Figure 6 , however, it will be understood that the number and spacing of the extension portions 76 can be different. The extension portions 76 project from the side of the stiffener 70 opposite to the stiffener flange 73. The extension portions 76 are part of a wavy surface. One extension portion 76 is arranged between each pair of adjacent openings 74. The extension portions 76 extend from the stiffener foot 71 to the free end.

[0060] Now referring to Figure 7 , a stiffener 70 is shown in a cross-section passing through the extension portion 76. The stiffener 70 includes a first stiffener member 80 and a second stiffener member 90. The first stiffener member 80 has a C-shaped configuration. The first stiffener member 80 includes a foot portion 81, a flat web portion 82, and a flange portion 83. The second stiffener member 90 has a Z-shaped configuration. The second stiffener member 90 includes a foot portion 91, a wavy web portion 92, and a flange portion 93.

[0061] The flat web portion 82 of the first stiffener member 80 is planar in the normal direction, i.e., in the direction of the longitudinal length of the stiffener 70. The flat web portion 82 does not have any bends or kinks along the longitudinal length. The flat web portion 82 provides a circumferential load in the normal direction. The foot portion 81 and the flange portion 83 of the first stiffener member extend parallel to each other. The foot portion 81 is shaped to correspond to the alignment of the inner side 23 of the panel 21 and the stringer 30.

[0062] The wavy web portion 90 includes wavy portions 94. The wavy portions 94 form the extension portions 76. The wavy portions 94 extend transversely to the longitudinal axis of the stiffener 70. A straight portion 95 is arranged between each pair of wavy portions 94. The straight portion 95 is planar. The straight portion 95 is configured to align with the flat web portion 82 of the first stiffener member 80. The wavy portions 94 are configured to be spaced from the first stiffener member 80. Each wavy portion 94 is generally U-shaped.

[0063] When the stiffener 70 is formed, the straight portion 95 is aligned with the planar web portion 82 of the first stiffener member 80. The web feet 81 and the web feet 82 extend in opposite directions, and the flange portion 83 and the flange portion 93 overlap each other. The corrugated portion 94 forms a space 97 between the first stiffener member 80 and the second stiffener member 90. The arrangement of the flange portions encloses the free end of the corrugated portion 94. In the current arrangement, the flange portion 93 of the second stiffener member 90 encloses the corrugated portion. In an alternative embodiment, the flange portion 83 of the first stiffener member 80 encloses the corrugated portion.

[0064] A core 100 is disposed in each corrugated portion 94. The core 100 is sandwiched between the first stiffener member 80 and the second stiffener member 90. The core 100 is formed of a block. In the current embodiment, the core is formed of a polymeric block such as Nomex material (Nomex TM )). Other suitable materials such as PVC foam and polyurethane foam can be used. The core 100 is formed as a columnar portion. The core conforms to the shape of the corrugated portion 94 that receives the core 100. When sandwiched between the first stiffener member 80 and the second stiffener member 90, the core 100 extends between the stiffener foot 71 and the free end. The core 100 is enclosed at the free end. The core 100 is preformed and disposed between the first stiffener member 80 and the second stiffener member 90. Alternatively, the core is formed by inserting a material into the space between the first stiffener member 80 and the second stiffener member 90 and then curing the material. The core 100 fills the space. The core 100 can be omitted.

[0065] An internal prepreg layer 110 is disposed between the first stiffener member 80 and the second stiffener member 90. Corresponding prepreg layers can be disposed along the inner sides of each of the first stiffener member 80 and the second stiffener member 90. The core 100 can be disposed between the prepreg layers. The core 100 abuts against the prepreg layer 110.

[0066] The configurations of the first stiffener member 80 and the second stiffener member 90 can be different. For example, the first stiffener member 80 can have an L-shaped or Z-shaped configuration, while the second stiffener member 90 can have a C-shaped or L-shaped configuration. Figure 8 An alternative embodiment is shown in which the first stiffener member 80 has a Z-shaped configuration and the second stiffener member 90 has a corresponding Z-shaped configuration. The foot portion 81 of the first stiffener member 80 and the foot portion 91 of the second stiffener member 90 are stacked to form a single stiffener foot 71. The flange portion 83 of the first stiffener member 80 and the flange portion 93 of the second stiffener member 90 are stacked to form a single stiffener flange 73. The core 100 extends between the stiffener foot 71 and the stiffener flange 73.

[0067] Reference Figures 9 to 11 , a differential frame configuration is shown. The fuselage mechanism 20 includes a panel 21 and stringers 30 generally as described above. However, the fuselage mechanism 20 is shown as having a stringer arrangement with an inverted U-shaped configuration. In this arrangement, the stringers are arranged such that the stringer feet 31 are disposed on the inner side 23 of the panel, where two stringer webs 33 stand upright from each edge of the stringer feet 31. A stringer flange 34 extends from the free end of each stringer web 33. An extended flange portion 35 extends from the stringer flange 34. In this differential frame configuration, stiffeners 70 are disposed on the stringer flange 34. The stiffeners 70 are disposed on the extended flange portion 35. It will be understood that the configuration of the stringers 30 can be changed. Stringers with different configurations can be arranged on the panel 21. Alternatively or additionally, for example, the stringers can have a T-shaped, U-shaped, Z-shaped, L-shaped or I-shaped configuration.

[0068] In Figure 9 , three stiffeners or frames 70 are shown. It will be understood that the number of stiffeners 70 can be changed. The stiffeners 70 extend perpendicular to the stringers 30. Adjacent stiffeners 70 are spaced apart from each other. The stiffeners 70 have a Z-shaped configuration. The shape of the frame can be changed. The stiffeners 70 can have an annular configuration such as a C-shaped, L-shaped or J-shaped, for example. The stiffeners 70 are directly mounted to the stringers 30. The stiffeners 70 are spaced apart from the inner side 23 of the panel 20 by the stringers 30. The stiffeners 70 extend perpendicular to the longitudinal axis of the fuselage 11. The stiffeners 70 extend in a circumferential arrangement. Thus, the stiffeners are arcuate. The stiffeners 70 are formed of a composite layer, although the composition and material of the stiffeners can be different.

[0069] The stiffeners 70 are fixed to the stringers 30, for example, by bolt connection or bonding. As shown in Figure 11 , the stabilizers 120 extend between the inner side 23 of the panel 30 and the stringers 30. A stabilizer 120 is disposed at each stringer 30. The stabilizers 120 are arranged in pairs at each stringer 30, although the number of stabilizers 120 can be changed. The stabilizers 120 are mounted to the planar web portion 82 of the first stiffener member 80. The stabilizers 120 help transfer the load to the panel 21 and thus help minimize the thickness of at least a portion of the stringers 30, such as the flange of the stringers.

[0070] The arrangement of the stiffeners 70 in the differential frame configuration is as described above, particularly with reference to Figure 6 and Figure 8The arrangements of the stiffeners 70 described are substantially the same. Therefore, a detailed description will not be repeated. It will be understood that in the case of a differential frame configuration, the openings 75 provided for an integral frame configuration can be omitted. In the present embodiment, each stiffener foot 71 is directly fixed to the stringer flange 34 and the extended flange portion 35. The extended flange portion 35 can be omitted. The stiffener foot 74 is attached to the stringer 30.

[0071] The corrugated web portion 90 together with the core 100 eliminates the need for clips to attach the stiffeners to the panel. In addition, the size, number, and weight of the stringers 30 and any components for mounting the stiffeners to the panel 20 can be substantially minimized.

[0072] The corrugations 94 provide lateral stability. The core 100 contributes to lateral stability. By sandwiching the core 100 between two structural layers, the lateral stability can be maximized. The sandwich arrangement contributes to the stiffness of the stiffener web 72. By providing corrugations in one part of the stiffener web 72 and maintaining a planar configuration in another part, lateral stability can be provided while maintaining the hoop load along the longitudinal length of the stiffener 70. Thus, the lateral stability becomes an inherent part of the structure. This arrangement eliminates or limits the need for additional clips, splints, and stabilizers.

[0073] Now referring to Figures 12a to 12d , a method of forming the stiffener 70 will now be described. This method will be described with reference to the stiffener 70 described above with reference to Figure 6 and Figure 7 , however, it will be understood that alternative stiffener embodiments can be formed. It will also be understood that the stiffener 70 can be formed by alternative processes. A tool 125 is provided for forming the stiffener 70. The tool 125 includes a convex tool 130 and a concave tool 140.

[0074] In Figure 12a , the convex tool 130 is provided. The convex tool 130 is configured to form the configuration of the first stiffener component 80. The convex tool 130 has the configuration of the first stiffener component 80. A cutout 131 is formed in the tool to define the features of the first stiffener component 80, such as the opening 74. The prepreg sheet 132 is disposed on the convex tool 130. The first stiffener component 80 can be in a cured or uncured state, depending on the stage at which curing is carried out.

[0075] In Figure 12bTherein, a concave tool 140 is provided. The concave tool 140 is configured to form the configuration of the second stiffener member 90. The concave tool 140 has the configuration of the second stiffener member 90. A cutout 141 is formed in the tool to define features of the second stiffener member 90, such as the opening 74. A prepreg sheet 142 is disposed on the concave tool 140. The second stiffener member 90 may be in a cured or uncured state, depending on the stage at which curing is carried out. The second stiffener member 90 is placed on the concave tool by defining corrugations 94 in the second stiffener member 90. An internal prepreg layer 110 is disposed on the inner side of the second stiffener member 90.

[0076] A core 100 is disposed in each of the channels formed by the corrugations 94. The core 100 extends in the radial direction. The core 100 is preformed in the current arrangement. As shown in Figure 12c the internal prepreg layer 110 is disposed on the core 100 on the second stiffener member 90.

[0077] In Figure 12d the convex tool and the concave tool are placed together to form an assembled stiffener 70. The convex tool 130 and the concave tool 140 are aligned with the first stiffener member 80 and the second stiffener member 90. The assembled stiffener is cured with the first stiffener member 80 and the second stiffener member 90 bonded together. In the current arrangement, the stiffener 70 is cured separately from the panel 21 and the stringer 30. In an alternative arrangement, the stiffener 70 is cured together with the panel 21 and the stringer 30, i.e., cured in place. Thus, the stiffener tool can form part of an assembly tool.

[0078] Although the above embodiments have been described with reference to an aircraft fuselage, it will be understood that the arrangements described herein are applicable to other aircraft components. For example, the aircraft component may be an aircraft wing.

[0079] When the word "or" appears, this should be understood to mean "and / or", such that the items mentioned are not necessarily mutually exclusive and can be used in any suitable combination.

[0080] Although the present invention has been described above with reference to one or more preferred embodiments, it will be understood that various changes and modifications can be made without departing from the spirit of the invention as defined in the appended claims.

Claims

1. A stiffener for an aircraft component, the stiffener comprising: A first stiffener member having a planar web portion that is planar along a longitudinal direction of the first stiffener member; A second stiffener member arranged together with the first stiffener member, wherein the second stiffener member includes a corrugated web portion that includes a plurality of corrugations spaced apart along a longitudinal length of the corrugated web portion, each corrugation forming an extension and extending transverse to the longitudinal length of the planar web portion; And A plurality of cores, each core being arranged in a respective one of the corrugations and between the planar web portion and the corrugated web portion.

2. The stiffening rib according to claim 1, wherein, Each of the cores is sandwiched between the planar web portion and the corrugated web portion.

3. The stiffener according to claim 1 or 2, wherein The core includes a polymer block.

4. The stiffening rib according to claim 3, wherein, The polymer block is made of Nomex material.

5. The stiffener according to claim 1 or 2, wherein Each of the cores includes a columnar portion.

6. The stiffener according to claim 1 or 2, wherein The planar web portion and the corrugated web portion form a web, and the stiffener includes a foot extending from the web.

7. The stiffening rib according to claim 6, wherein The core extends from the foot to a free end of the stiffener.

8. The stiffening rib according to claim 7, wherein At least one of the first stiffener member and the second stiffener member overlaps with the core at the free end.

9. The stiffener according to claim 1 or 2, including a prepreg layer located between the planar web portion and the corrugated web portion.

10. The stiffening rib according to claim 1 or 2, wherein, The first stiffener member is in at least one of a C-shaped, L-shaped, and Z-shaped configuration, and the second stiffener member is in at least one of a C-shaped, L-shaped, and Z-shaped configuration.

11. The stiffener according to claim 1 or 2, wherein, The stiffener is a frame for an aircraft fuselage.

12. A stiffener for an aircraft component, the stiffener comprising: A first stiffener member having a planar web portion and a foot, the planar web portion being planar along a longitudinal direction of the stiffener member; A second stiffener member including a corrugated web portion that includes a plurality of corrugations spaced apart along a longitudinal length of the corrugated web portion, each corrugation forming an extension and extending transverse to the longitudinal length of the planar web portion; And A plurality of cores, each core being arranged in a respective one of the corrugations and between the planar web portion and the corrugated web portion, and each core including a block that extends transversely to the longitudinal direction of the first stiffener member between the foot and the free end.

13. An aircraft component including a panel, a spar, and a stiffener according to any one of claims 1-12.

14. The aircraft assembly according to claim 13, wherein, The spar is configured to extend through the stiffener, and the stiffener is configured to be mounted to the panel.

15. The aircraft component according to claim 13, wherein, The spar is configured to be arranged between the stiffener and the panel, and the stiffener is configured to be mounted to the spar.

16. The aircraft assembly according to claim 15, comprising a stabilizer configured to be mounted between the panel and the stiffener.

17. An aircraft fuselage comprising at least one of the stiffeners according to any one of claims 1 to 12 and the aircraft assembly according to any one of claims 13 to 16.

18. A method of forming a stiffener for an aircraft assembly, the method comprising: holding a first stiffener member having a planar web portion, wherein the planar web portion is planar in a longitudinal direction of the first stiffener member; holding a second stiffener member having a corrugated web portion, wherein the corrugated web portion includes a plurality of corrugations spaced apart along a longitudinal length of the corrugated web portion, each corrugation forming an extension portion and extending transverse to the longitudinal length of the planar web portion; disposing a plurality of cores, respectively, in a corresponding one of the plurality of corrugations; and clamping each of the cores between the planar web portion of the first stiffener member and the corrugated web portion of the second stiffener member.

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