Composite structure having an integrated support

Abstract

A composite structure (1) for an aircraft, having at least one insert (2) for receiving attachment devices, each insert (2) includes a core (3) having a major dimension and containing at least one through-hole (4), and a composite strip arrangement formed by a first section (5) surrounding the core (3) and attached to said core (3) by an adhesive polymeric layer, and a second section (6) including at least one free end (6a). The first (5) and the second portion (6) of the composite strip arrangement are disposed over a first surface (1a) of the composite structure (1), such that the major dimension of the core (3) is positioned transversal to said first surface (1 a). The at least one insert (2) is co-cured with the composite structure (1).

Claims

1. A composite structure for an aircraft comprising: a first surface of the composite structure; at least one insert configured to receive attachment devices, wherein the at least one insert includes: a core having a major dimension and including at least one through-hole, and a composite strip arrangement formed by a first section adjacent the core and attached to the core by an adhesive polymeric layer, and a second section adjacent the core and attached to the first section, wherein the second section includes at least one free end; wherein at least one part of both the first section and the second section of the composite strip arrangement is disposed on a first surface of the composite structure, and the major dimension of the core is positioned substantially transverse to the first surface of the composite structure; wherein the at least one insert is co-cured with the composite structure form a single piece of the composite structure and the insert, and wherein the at least one insert is configured to receive at least one attachment device.

2. The composite structure according to claim 1, wherein the composite structure has opposite edges, and wherein the second section extends between the opposite edges and is configured to provide support for attachment devices to be attached to the at least one insert.

3. The composite structure according to claim 1, wherein the core is formed by foam polymer or short-fiber thermoplastic polymer.

4. The composite structure according to claim 1, wherein the core has a polygonal shape.

5. The composite structure according to claim 1, wherein the at least one through-hole in the core is positioned at an outermost section of the core and away from the second section.

6. The composite structure according to claim 1, wherein the insert includes a metal bush received in the through-hole of the core, wherein the metal brush formed of an aluminum alloy, titanium or a steel alloy.

7. An attachable system for an aircraft comprising: a composite structure including a first surface; an insert including a composite core plate with a through hole and composite strip sections adjacent edges of the composite core plate, wherein the composite strip sections adhere to the core pate, wherein an exposed surface of at least one of the composite strip sections abuts and is secured to the first surface of the composite structure; and an attachment device including a clamp and the attachment device fixed to the insert by a fastener in the through hole; wherein a long edge of the core plate is adjacent the first surface such that one of the composite strip sections is sandwiched between the long edge and the first surface; wherein a free end of at least one of the composite strip sections extends beyond the core plate and is secured to the first surface.

8. The attachable system according to claim 7, wherein the attachment device includes a bracket configured to support the clamp, wherein the bracket is partially disposed on the insert and fixed to the insert by the fastener.

9. The attachable system according to claim 8, wherein the bracket and the clamp are a single body component.

10. The attachable system according to claim 8, wherein the fastener includes a spacer which elevates the clamp above the insert.

11. The attachable system according to claim 7, wherein the attachment device further comprises a tubular spacer disposed between the clamp and the through-hole of the core.

12. The attachable system according to claim 7, wherein the clamp has an annular body and opposing projections, wherein one of the opposing projections has an aperture to receive the fastener, and the other of the opposing projections ends at a tubular spacer on the fastener, wherein the spacer has a threaded end to fix the clamp to the insert.

13. The attachable system according to claim 7, wherein the clamp is one of a saddle clamp, a P-clamp, and a double P clamp.

14. A method to manufacture a composite structure comprising: forming providing an insert by applying an adhesive layer on a first composite strip to an outer edge of a core plate having a through hole, wherein a long edge of the core plate is not covered by the first composite strip; applying the long edge of the core plate to a first side of a second composite strip and applying a portion of the first composite strip to a portion of the second composite strip beyond the core plate, wherein the first and second composite strips entirely cover peripheral edges of the core plate; attaching a second side of the second composite strip to a first surface of the composite structure, such that the second composite strip is sandwiched between the first surface and the long edge of the core plate and portions of the second side of the second composite strip beyond the core plate extend are attached to the first surface; and curing the insert and the composite structure together such that the insert with the core plate and first and second composite strips and the composite structure form a single piece composite structure.

15. The method according to claim 14, further comprising, after the curing, fixing a clamp to the insert by a fastener engaging the clamp and the at least one through-hole of the core plate.

Description

SUMMARY OF DRAWINGS

(1) For a better comprehension of the invention, the following drawings are provided for illustrative and non-limiting purposes, wherein:

(2) FIGS. 1A and 1B show a schematic perspective view of a composite structure having an insert for receiving attachment devices.

(3) FIG. 2 shows a detailed view of an attachable system formed by a composite structure having an insert, and an attachment device.

(4) FIG. 3 shows a detailed view of an attachable system comprising another attachment device.

(5) FIG. 4 shows a detailed view of an attachable system comprising a further attachment device.

(6) FIG. 5 shows a detailed view of an attachable system comprising another attachment device.

(7) FIGS. 6A and 6B show a detailed view of an attachable system comprising a further attachment device. FIG. 6A shows a perspective view and FIG. 6B shows a cross-sectional and perspective view.

(8) FIGS. 7A and 7B show a detailed view of an attachable system having a core. FIG. 7A shows a perspective view of an insert with several through-holes, and FIG. 7B shows a perspective view of external routing attached to the insert shown in FIG. 7A.

(9) FIG. 8 show different steps of a method for manufacturing a composite structure.

DETAILED DESCRIPTION

(10) FIG. 1 shows a composite structure 1 for an aircraft according to a preferred embodiment. The composite structure 1 has at least one insert 2 for receiving attachment devices, wherein the at least one insert 2 comprises a core 3 and a composite strip arrangement.

(11) As shown in the detailed view of FIG. 1, the composite structure 1 comprises several inserts 2 in where each core 3 contains at least one through-hole 4 intended to receive attachment devices for attaching external routing 10 to the structure 1.

(12) Each core 3 has a major dimension for being positioned substantially transversal with respect to a first surface 1a of the composite structure 1. The core 3 may be a composite plate having a thickness substantially smaller than the length and width of the core. If the core is triangular in shape, the major dimension is the length of the base of the triangle. The major dimension of the core 3 may be the length of the longest edge of the core. Positioning the major dimension of the core 3 against the surface 1a of the structure provides good support to the core by the structure 1. This good support will help support the hydraulic and electric systems' routings which will be attached to the core 3.

(13) As also shown in FIG. 1, the composite strip arrangement is formed by several first sections 5 and one second section 6 attached to the first sections 5. Every first section 5 is disposed around every core 3 and attached to it by an adhesive polymeric layer, while the second section 6 comprises two free ends 6a, 6b extended between the two opposite edges 1b, 1c of the composite structure 1 for its attaching to the structure 1.

(14) Inserts 2 (core 3 and composite strip arrangement) are co-cured with the composite structure 1 to thus obtain a composite structure 1 with integrated inserts 2 for the reception of attachment devices.

(15) According to an embodiment, the core 3 is formed by foam polymer, or short-fiber thermoplastic polymer, such as polyetherimide ULTEM, or fiberglass.

(16) The core 3 may have a polygonal shape, such as a triangular shape. The triangular shape offers an easily distinguished major dimension for its positioning in the structure 1, and provides sufficient support for the attachment devices and more free space for the installation tasks.

(17) The at least one through-hole 4 of the core 3 may be positioned in the outermost section of the core 3 to provide greater clearance and easier installation of the attachment devices.

(18) The insert 2 may include a metal bush in the at least one through-hole 4 of the core 3, wherein the metal bush is formed by aluminum alloy, or titanium, or steel alloy.

(19) FIGS. 2 to 5, 6A, 6B, 7A and 7B show attachable systems for an aircraft, where each system includes a composite structure 1 having an insert 2 as above described, and an attachment device comprising a clamp 7 attaching the external routing 10, and fixed to the insert 2 via the at least one through-hole 4 of the core 3.

(20) As shown in FIG. 2, the attachment device may further comprise a bracket 8 configured to support the clamp 7, and being partially disposed onto the insert 2 and fixed to said insert 2 by the at least one through-hole 4 of the core 3. The bracket 8 and the clamp 7 may be form as a single body.

(21) FIG. 3 shows a detailed view of an attachable system having an attachment device formed by a spacer 9, and a P clamp 7 formed together with a bracket 8 in a single body. The spacer 9 is configured as a tubular body, and disposed between the clamp 7 and the at least one through-hole 4 of the core 3, to provide clearance between the attachment device and the insert 2. The bracket 8 provides support for both the clamp 7 and the external routing 10, facilitating thus the installation of the external routing 10.

(22) FIG. 4 shows a detailed view of an attachable system with a simplified attachment device that comprises a spacer 9 and a P clamp 7. This device may be used when only one pipe (hose or wire) has to be attached, and there is no need for providing clearance between the pipe (hose or wire) and the composite structure 1.

(23) FIG. 5 shows a detailed view of an attachable system with another simplified attachment device that comprises a spacer 9 and a double P clamp 7. This device may be used when two pipes (hoses or wires) have to be attached, and there is no need for providing clearance between the pipes (hoses or wires) and the composite structure 1.

(24) FIGS. 6A and 6B show a perspective and a cross-sectional detailed view of an attachment device comprising a clamp 7 having an annular body and two opposing projections 12a, 12b. One of the projections 12a being perforated to receive a fastener for retaining the external routing 10 inside the clamp 7, and the other projection 12b being terminated with a spacer 9 configured as a tubular body to provide clearance with the insert 2. The spacer 9 has a threaded end 9a to fix the clamp 7 to the insert 2 via the at least one through-hole 4 of the core 3.

(25) The attachment device further comprises a fastener 11 attaching the clamp 7 to the insert 2 via the at least one through-hole 4 of the core 3.

(26) The clamp 7 of FIG. 6 can be directly screwed to the nut 13 with no need of using a screw. Furthermore, in order to stop the clamp 7 from unscrewing itself from the nut 13 (due to possible vibrations) a self-locking nut 13 or any other similar device may be used. Preferably, a washer 14 will be placed between the nut 13 and core 3.

(27) FIGS. 7A and 7B show a detailed view of an attachable system having a core 3 according to another preferred embodiment. As shown in FIG. 7a, the core 3 may have several through-holes 4, misaligned to prevent clamps 7 from colliding when attached to the insert 2. FIG. 7b shows a perspective view of external routing 10 attached to the core 3 shown in FIG. 7a.

(28) FIG. 8 illustrates a method for manufacturing a composite structure 1 having at least one insert 2 for receiving attachment devices. The method comprises:

(29) (i) providing at least one insert 2 comprising a core 3 having a major dimension and containing at least one through-hole 4, and a composite strip arrangement formed by a first strip section 5 bordering the core 3 and attached to the core 3 by an adhesive polymeric layer on surface of the first strip sections 5 facing the core 3. The second strip section 6 includes a strip portion between the ends of the first section 5 and one or two free strip end 6a that extend beyond the first section 5. The adhesive polymeric layer at the ends of the first strip section 5 overlaps the second strip section 6 and adheres to the second strip section 6. The core 3 is inserted in an interior area bounded by the first and second strip sections 5, 6. The adhesive polymeric layer secures the core to the first and second strip sections 5, 6.

(30) (ii) placing at least one part of both the first 5 and the second portion 6 of the composite strip arrangement over a first surface 1a of the composite structure 1, such that the major dimension of the core 3 is positioned substantially transversal to said first surface 1a of the composite structure 1. An exposed surface of the first and/or second strip sections 5, 6 may be placed against the surface 1a of the plain composite structure 15.

(31) (iii) curing the at least one insert 2 and the composite structure 15 together to obtain a single piece composite structure 1 with an integrated insert 2 for receiving attachment devices.

(32) FIG. 8 shows different steps of the method. The steps (from left to right in FIG. 8) include providing at least one core 3 having a major dimension and containing at least one through-hole 4, and at least one composite strip arrangement formed by at least one first section 5, and a second section 6 comprising at least one free end 6a for attachment to a plain composite structure 15.

(33) The next step is providing an insert 2 including the core 3 and the first strip section 5 surrounding the core 3 attached to the core 3 by an adhesive polymeric layer, the section strip section 6, and the plain composite structure 15 to which the insert 2 is going to be co-cured.

(34) The composite structure 1 is formed by curing the insert 2 and the plain composite structure 15. The resulting composite structure may include several inserts 2 and the composite strips 5, 6, may extend along the entire length of the structure 1.

(35) The method may further include fixing a clamp 7 to the insert 2 via the at least one through-hole 4 of the core 3) to thus allow attaching external routing 10 to the insert 2.

(36) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.