DAMPING SKIN SYSTEM FOR PROTECTING COMPOSITE PARTS

Abstract

Damping skin for protecting composite parts includes a composite material having at least two superposed layers, namely a first layer formed from the juxtaposition of hollow spheres, which is intended to be applied and fixed, either directly or indirectly, to the surface of the part to be protected and a second layer covering the first and formed from a wall made of a material having plastic deformation properties.

Claims

1. A damping skin system for protecting composite parts, said damping skin system comprising: a substrate comprised of a first composite material and having a surface, said first composite material being comprised of a first structural component and a first resin; a skin comprised of a second composite material and a wall layer, said second composite material being comprised of a second structural component and a second resin, wherein said second composite material is a first layer and said wall layer is a second layer, said first layer and said second layer being superposed, said second layer covering said first layer, wherein said second structural component is comprised of a juxtaposition of hollow spheres applied and fixed to said surface, and wherein said second layer is comprised of a moldable and resilient material, said first composite material having more mechanical resistance than said first layer.

2. The damping skin system according to claim 1, wherein said second structural component of said first layer comprises superposition of several layers, each layer being comprised of juxtaposition of hollow spheres, each layer of hollow spheres being separable from other layers of hollow spheres by an intermediate wall.

3. The damping skin system according to claim 1, said skin further comprising: a third layer affixed to said first layer on one side and affixed to said surface of said substrate on an opposite side, said third layer having a means for removable attachment in contact with said surface of said substrate.

4. The damping skin system according to claim 1, wherein said hollow spheres are comprised of a material selected from a group consisting of metal, synthetic materials, minerals, or a combination thereof.

5. The damping skin system according to claim 1, wherein said hollow spheres have different diameters, each layer of hollow spheres having spheres with diameters independent from other layers.

6. The damping skin system according to claim 1, wherein said wall layer is comprised of at least one sheet of a composite tissue.

7. The damping skin system according to claim 6, wherein said composite tissue is comprised of an aramid polymer.

8. The damping skin system according to claim 6, wherein said composite tissue has components having properties selected from a group consisting of insulating ability, conductivity or both.

9. The damping skin system according to claim 1, wherein said hollow spheres are assembled by gluing to at least one of a group consisting of: each other, said wall layer, and said surface of said substrate.

10. The damping skin system according to claim 9, wherein said hollow spheres are assembled by a said second resin applied at points of contact of said hollow spheres.

11. The damping skin system according to claim 1, said skin further comprising: a compressible material filling in space remaining between said hollow spheres of said second composite material, said compressible material having a compression resistance lower than a compression resistance of said hollow spheres.

12. The damping skin system according to claim 1, wherein said second composite material of said skin has thickness, corresponding to said first composite material of said substrate.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0050] FIG. 1 represents a schematic cross-sectional view of a portion of an object covered with a damping skin according to the invention.

[0051] FIG. 2 represents a schematic cross-sectional view of a portion of an object covered with a variant of the same damping skin.

[0052] FIG. 3 represents a schematic cross-sectional view of a portion of an object covered with another variant of the same damping skin.

[0053] FIG. 4 represents a schematic cross-sectional view of an enlarged detail of the same damping skin.

[0054] FIG. 5 represents a schematic cross-sectional view of the same portion of an object covered with a damping skin, during an impact.

[0055] FIG. 6 represents a schematic cross-sectional view of a portion of an object covered with another variant of the same damping skin.

DETAILED DESCRIPTION OF THE INVENTION

[0056] FIG. 1 shows an object 1, a part made of a composite material for example, whose external wall 10 is covered with a damping skin 2 according to the invention.

[0057] Said damping skin 2 consists of two layers, a first layer 3 consisting of the juxtaposition of hollow spheres 4, fixed to the wall 10, and a second layer 5, covering the first, and made of a material having plastic deformation properties.

[0058] The hollow spheres are of a known type, already used in the field of shock absorbers for example, they can be made of different materials, including metal or synthetic materials as well.

[0059] The layer 5 consists of a sheet which can be made in different manners, of a composite tissue, or of several composite tissues stratified between them, the number of tissues, as well as their thickness and their texture being chosen according to the use of the skin.

[0060] Said tissues are preferably, but not restrictively, made of aramid polymer.

[0061] FIG. 2 shows that, according to a variant, the first layer 3 itself consists of the superposition of two layers 30 and 31 of hollow spheres 4.

[0062] FIG. 3 shows that, in another variant, the first layer 3 also consists of the superposition of two layers 30 and 31 of hollow spheres 4, and that said two layers 30 and 31 are separated by an intermediate wall 32.

[0063] Referring to FIG. 4, it can be seen that the hollow spheres 4 are connected between them, and to the wall 10 as well as to the second layer 5, by gluing, by means of resin bonds 33 for example. The operation of gluing is made with a controlled quantity of resin, so that the bonds 33 are localized to the points of contact of the spheres between each other, and between them and the wall 10 and the wall 5, so as to form nothing but meniscuses, in order to cover only a limited portion of the spheres 4, and not to deteriorate the properties thereof.

[0064] It should be noted that the space E, delimited by the walls 10 and 5, as well as by the hollow spheres 4, can be left empty or be filled with a compressible material, with a compression resistance that is lower than that of the hollow spheres 4, such as a foam or an elastomer for example.

[0065] Referring now to FIG. 5, one can see the effect of an impact by an element G, on an object 1 covered with a damping skin 2.

[0066] Obviously, it is easy for a maintenance operator to detect an impact area and assess the extent of the damages, then to repair the damping skin 2 by removing the damaged hollow spheres 4 and replacing them, then covering with a wall part 5.

[0067] Referring now to FIG. 6, one can see a damping skin 2 according to the invention made integral indirectly with the wall 10 by means of a wall 6. The damping skin 2 thus includes two walls 5 and 6 between which a layer 3 of hollow spheres 4 is placed.

[0068] The wall 6 can have various aspects, and it can consist of various materials. Its principal feature consists in that its face 60, designed to enter into contact with the wall 10, is designed capable of being made integral with the latter.

[0069] This integral connection can be made by adhesion through gluing means the adhesion capacity of which is more or less considerable.

[0070] In case of a small adhesion, it is possible to make an integral connection reversible at will, permitting to ensure the temporary protection of an object.

[0071] The damping skin 2, comprising such a wall 6, can thus be conditioned with sheets, patches, strips etc, having possibly certain flexibility, and the face 60 of which is coated with an adhesive product.