초록 ▼

A structure (2) for an aircraft (1) comprises transverse walls (3-8) connected to longitudinal walls (9-12); each wall (3-12, 18, 18B) comprises two jackets (19) of composite material disposed on either side of an intermediate arrangement (20); a wall includes a corrugated core (70) presenting corru

A structure (2) for an aircraft (1) comprises transverse walls (3-8) connected to longitudinal walls (9-12); each wall (3-12, 18, 18B) comprises two jackets (19) of composite material disposed on either side of an intermediate arrangement (20); a wall includes a corrugated core (70) presenting corrugations extending along an axis (Z) substantially parallel to the jacket, such that the capacity of the wall to absorb energy in the event of an impact along said axis is increased; a wall includes a zone of weakness (45) encouraging controlled degradation of the wall in the event of such a shock.

대표청구항 ▼

What is claimed is: 1. A fuselage structure (2) of a rotary wing aircraft, comprising: vertical walls, comprised of transverse walls (18B) and longitudinal walls (18); a cross-strut section member (21) joining the longitudinal walls (18) to the transverse walls (18a); and a cylindrical delaminating

What is claimed is: 1. A fuselage structure (2) of a rotary wing aircraft, comprising: vertical walls, comprised of transverse walls (18B) and longitudinal walls (18); a cross-strut section member (21) joining the longitudinal walls (18) to the transverse walls (18a); and a cylindrical delaminating insert (26), having a frustoconical head, located at a base (21A) of the section member (21), wherein each of the vertical walls comprises an intermediate arrangement (20) and two planar jackets (19) of composite material disposed on either side of the intermediate arrangement (20), wherein the intermediate arrangement of at least one of the vertical walls comprises a corrugated core (70) presenting corrugations extending along an axis (Z) substantially parallel to the planar jackets such that an energy-absorption capacity of the at least one of the vertical walls in an impact in a direction of the axis (Z) is increased, wherein a base of the at least one of the vertical walls includes a zone of weakness (45) where a thickness of the at least one vertical wall is reduced, wherein the corrugated core cooperates with the planar jackets to define cavities (61) shaped as portions of prisms of polygonal section with a cellular filler material (23, 24) filling the cavities, and wherein the delaminating insert (26) has a central axis extending parallel to the axis (Z), the delaminating insert (26) being configured to cooperate with a material of the section member surrounding the delaminating insert (26) to delaminate the material upon the occurrence of the impact. 2. The structure (2) according to claim 1, further comprising: a floor (13), wherein the transverse walls (3-8) are in the form of frames, and the longitudinal walls (9-12) are in the form of beams having cores extending along the axis (Z), wherein the axis (Z) is substantially vertical, and wherein said longitudinal walls, said corrugated core, and said zone of weakness extend under the floor. 3. The structure (2) according to claim 1, wherein the corrugated core of the intermediate arrangement portion (20) extends in waves, the waves coming flush with, or extending to locations of, the planar jackets (19). 4. The structure (2) according to claim 1, wherein each of the two planar jackets includes at least one zone of weakness (45) configured to encourage symmetrical deformation of a corresponding wall in the event of an impact. 5. The structure (2) according to claim 1, wherein the cellular filler material (23, 24) is a synthetic foam. 6. The structure (2) according to claim 1, wherein the zone of weakness (45) extends over a perpendicular zone being substantially perpendicular to the axis (Z) of the corrugations of the core (70). 7. The structure (2) according to claim 1, wherein the at least one of the vertical walls includes a stiffener (25) in the form of a concave depression extending within at least one of the planar jackets (19). 8. The structure (2) according to claim 1, wherein the zone of weakness (45) is a localized interruption in a layer of at least one of the planar jackets (19), the localized interruption forming part of a plastically-deformable anti-crash means and configured to initiate a rupture and further configured to suffer energy absorption by localized buckling. 9. The structure (2) according to claim 1, wherein the at least one of the vertical walls has a plurality of concave reinforcing depressions (25) extending along said axis (Z), the depressions being regularly spaced apart and formed in each of the planar jackets (19), the depressions configured to strengthen a lateral bending stiffness of the at least one vertical wall such that the at least one vertical wall is prevented from bending laterally in the event of the impact. 10. The structure (2) according to claim 1, wherein the corrugated core includes flattened portions of outer skin sectors (29) at a top and a bottom of the corrugations to provide a planar assembly surface. 11. The structure (2) according to claim 1, wherein an outer layer of the planar jackets (19) on the transverse walls (3-8) are cut, and wherein an outer layer of the planar jackets (19) on the longitudinal walls (9-12) is extended as far as a heel (47) of the longitudinal walls (18). 12. The structure (2) according to claim 1, wherein the vertical walls (3-12, 18, 18B) have i) layers with cuts formed by successive flare segments (31) extending initially substantially in elevation perpendicularly from opposite edges of the wall (18) and then angled (33) at an angle of about 90°, and ii) advance segments (34) extending substantially transversely to the proximity of a central strip (38), odd-numbered layers having the cuts with the advance segments (34) extending in a first direction from the angled segment (33), and even-numbered layers have the cuts with the advance segments (34) extending in a second direction opposite to the first direction. 13. The structure (2) according to claim 1, wherein the vertical walls (4-12, 18, 18B) include i) layers with cuts that are inclined at an angle (I, J) of about 45° in a longitudinal and transverse plane (X, Y), the cuts being inclined in a first direction for odd-numbered layers and in a second direction opposite the first direction for even-numbered layers, folds (37) forming central rectangular flaps (38) of a longitudinal main axis extending transversely on either side of quadrilateral flaps (39), ii) a longitudinal fold edge (37) being remote from the central flaps (38), and iii) two intersecting edges (42) coinciding with a corner of said flaps (38) and extending at substantially 45° relative to a transverse axis (Y). 14. A rotary wing aircraft (1), including the structure (2) according to claim 1. 15. The structure (2) according to claim 1, wherein the planar jackets (19) and the corrugated core (70) of the at least one of the vertical walls comprises a plurality of layers of fibers or fabrics, the fibers or fabrics being impregnated with epoxy resin. 16. The structure (2) according to claim 1, wherein the delaminating insert (26) is configured to burst a surrounding structure of the base (21A) of the section member (21) upon occurrence of the impact. 17. The structure (2) according to claim 1, wherein the delaminating insert (26) is configured to drill a channel inside at least the base (21A) of the section member (21) upon occurrence of the impact. 18. The structure (2) according to claim 1, wherein the cellular filler material (23, 24) is a honeycomb structure. 19. The structure according to claim 15, wherein the fibers or fabrics are one of i) made of carbon, ii) made of aramid, and iii) obtained from polyparaphenylene terephthalamide. 20. A fuselage structure for a rotary wing aircraft, comprising: vertical shock absorbing walls, comprising a longitudinal wall and a transverse wall; and a cross-strut section member joining the longitudinal walls to the transverse walls, the section member having a vertical stiffness greater than a vertical stiffness of the shock absorbing walls, wherein each of the vertical shock absorbing walls is comprised of generally planar outside jackets made of composite materials, and an internal corrugated core between the outside jackets, wherein surfaces of the corrugated core cooperate with inner surfaces of the outside jackets on sandwiching the corrugated core to form cavities in an interior of the shock absorbing walls, wherein foaming material fills the internal cavities of the shock absorbing walls, wherein a base of at least one of the shock absorbing walls are provided with a weakness zone where at least one outside jacket presents a thickness that is reduced, wherein the section member comprises a cylindrical delaminating nail, having a frustoconical head, inserted into a base of the section member, and wherein, in the event of an impact, the delaminating nail is configured to initiate a delamination of a material forming the section member and reduce the stiffness of the section member, and the weakness zone is configured to initiate a rupture of the at least one of the shock absorbing walls, such that the shock absorbing walls and the reduced stiffness of the of the section member cooperate to absorb an energy of the impact. 21. The fuselage structure according to claim 20, wherein the delaminating nail, in the event of the impact, reduces a strength of the section member in withstanding a force from the impact directed in a vertical direction, such that said strength becomes equivalent to a strength of the vertical walls in withstanding said force. 22. The fuselage structure according to claim 20, wherein the delaminating nail is configured to drill a channel inside at least the base of the section member upon occurrence of the impact.