Reinforcement of cellular materials
The invention pertains to a method for reinforcing cellular materials ( 1 ), a reinforced sandwich construction ( 5 ) as well as a correspondingly equipped aircraft. In the method, a cellular material ( 1 ) is provided with fiber bundles ( 3 ) that are introduced into the cellular material ( 1 ) with a needle ( 8 ). In this case, the needle ( 8 ) initially pierces a through-hole ( 2 ) into the cellular material ( 1 ) from one side in order to subsequently take hold of a fiber bundle ( 3 ) situated on the other side with the needle ( 8 ) and pull said fiber bundle into the cellular material ( 1 ).
1. A method for manufacturing a reinforced cellular material, the method comprising:
variably aligning a needle relative to a perpendicular axis of the cellular material by an arbitrary angle between 0 and 90 degrees;
producing a through-hole in the cellular material comprising foam material, by piercing the cellular material with the needle, wherein the through-hole extends from a first surface of the cellular material to a second surface of the cellular material;
making available at least one fiber bundle on the other side of the second surface of the cellular material;
reaching through the through-hole from the first surface to take hold of the at least one fiber bundle with the needle; and
pulling the at least one fiber bundle with the needle into the through-hole in the cellular material;
wherein the pulling step comprises pulling the at least one fiber bundle through a funnel-shaped nozzle prior to pulling the at least one fiber bundle through the cellular material,
wherein the through-hole is produced with a cross-sectional surface such that the at least one fiber bundle is compressed while being pulled through; and
wherein an orientation of the through-hole is configured to be individually adapted by varying the alignment of the needle such that the at least one fiber bundle is pulled into the cellular material with the needle at the arbitrary angle.
2. The method of claim 1 ,
wherein the needle is essentially inserted into the through-hole in the cellular material such that the needle is followed by the at least one fiber bundle.
3. The method of claim 1 , further comprising:
shearing off the at least one fiber bundle pulled into the through-hole such that the at least one fiber bundle ends flush with at least one of the first and second surfaces; or
placing the at least one fiber bundle pulled into the through-hole against at least one of the first and second surfaces.
4. The method of claim 1 , further comprising:
forming or arranging a cover layer on at least one of the first and second surfaces.
5. The method of claim 1 , further comprising:
filling the through-hole containing the at least one fiber bundle with a matrix system.
6. The method of claim 1 ,
wherein the method begins anew after the at least one fiber bundle was pulled into the through-hole in the cellular material.
7. The method of claim 1 ,
wherein the reaching through the through-hole is simultaneously performed with the producing of the through-hole.
8. The method of claim 1 ,
wherein the at least one fiber bundle is taken hold of by being hooked in the needle.
9. The method of claim 8 ,
wherein an inner wall of the through-hole is prevented from being damaged by the needle with a closing mechanism configured for closing an eyelet.
10. The method of claim 1 ,
wherein the through-hole is produced with a cross-sectional surface smaller than double the thickness of the fiber bundle to be pulled therethrough such that the fiber bundle is compressed while being pulled through.
11. The method of claim 1 ,
wherein the reaching-through is simultaneously performed with the producing of the through-hole.
12. The method of claim 1 , wherein the cellular material comprises a cover layer,
wherein the through-hole is formed in the cover layer by the needle, and
wherein, after pulling the at least one fiber bundle with the needle into the through-hole in the cellular material, ends of the at least one fiber bundle are either (i) placed flatly against, and bonded to, the cover layer, or (ii) cut off flush with the cover layer.
13. The method of claim 1 , wherein the at least one fiber bundle is made available in a straight, stretched-out fashion in the vicinity of the second surface.
14. The method of claim 1 , wherein the producing the through-hole in the cellular material comprises simultaneously piercing the cellular material with a plurality of needles, and
wherein making at least one fiber bundle available comprises making a corresponding number of fiber bundle available.
15. A method for manufacturing a reinforced cellular material, the method comprising:
variably aligning a needle relative to a perpendicular axis of the cellular material by an arbitrary angle which is between 0 and 90 degrees;
producing a through-hole in the cellular material, which comprises foam material, by piercing the cellular material with the needle, wherein the through-hole extends from a first surface of the cellular material to a second surface of the cellular material;
making available at least one fiber bundle on the other side of the second surface of the cellular material;
reaching through the through-hole from the first surface to take hold of the at least one fiber bundle with the needle; and
pulling the at least one fiber bundle with the needle into the through-hole in the cellular material such that the needle is followed by the at least one fiber bundle;
wherein the pulling step comprises pulling the at least one fiber bundle through a funnel-shaped nozzle prior to pulling the at least one fiber bundle through the cellular material,
wherein the through-hole is produced with a cross-sectional surface such that the at least one fiber bundle is compressed while being pulled through; and
wherein an orientation of the through-hole is configured to be individually adapted by varying the alignment of the needle such that the at least one fiber bundle is pulled into the cellular material with the needle at the arbitrary angle.
16. A method for manufacturing a reinforced cellular material, the method comprising:
variably aligning a needle relative to a perpendicular axis of the cellular material by an arbitrary angle which is between 0 and 90 degrees;
producing a through-hole in the cellular material, which comprises foam material, by piercing the cellular material with the needle, wherein the through-hole extends from a first surface of the cellular material to a second surface of the cellular material;
making available at least one fiber bundle on the other side of the second surface of the cellular material;
reaching through the through-hole from the first surface to take hold of the at least one fiber bundle with the needle; and
pulling the at least one fiber bundle with the needle into the through-hole in the cellular material;
wherein the pulling step comprises pulling the at least one fiber bundle through a funnel-shaped nozzle prior to pulling the at least one fiber bundle through the cellular material,
wherein the individual fibers of the at least one fiber bundle are essentially aligned straight and tightly pressed against one another in the through-hole; and
wherein an orientation of the through-hole is configured to be individually adapted by varying the alignment of the needle such that the at least one fiber bundle is pulled into the cellular material with the needle at the arbitrary angle.
17. A method for manufacturing a reinforced cellular material, the method comprising:
producing a through-hole in the cellular material that extends from a first surface of the cellular material to a second surface of the cellular material;
making available at least one fiber bundle on the other side of the second surface of the cellular material;
reaching through the through-hole from the first surface to take hold of the at least one fiber bundle;
pulling the at least one fiber bundle into the through-hole in the cellular material; and
pulling the at least one fiber bundle through a funnel-shaped nozzle prior to pulling the at least one fiber bundle through the cellular material.
18. The method of claim 17 ,
wherein the through-hole is produced by piercing the cellular material with a needle.
19. The method of claim 18 ,
wherein the at least one fiber bundle is taken hold of by being hooked in the needle.
20. The method of claim 19 ,
wherein the needle is essentially inserted into the through-hole in the cellular material such that the needle is followed by the at least one fiber bundle.
21. The method of claim 18 ,
wherein the through-hole is produced with a cross-sectional surface smaller than double the thickness of the fiber bundle to be pulled therethrough such that the fiber bundle is compressed while being pulled through.
22. The method of claim 17 , furthermore comprising the steps of:
shearing off the at least one fiber bundle pulled into the through-hole such that the fiber bundle ends flush with at least one of the first and second surfaces; or
placing the at least one fiber bundle pulled into the through-hole against at least one of the first and second surfaces.
23. The method of claim 17 , furthermore comprising the step of:
forming or arranging a cover layer on at least one of the first and second surfaces.
24. The method of claim 17 , furthermore comprising the step of:
filling the through-hole containing the at least one fiber bundle with a matrix system.
25. The method of claim 17 ,
wherein the method begins anew after the at least one fiber bundle was pulled into the cross-sectional in the cellular material.