Sphere-based structural core layer and method for use in aircraft

1 . A reinforcing core for a panel assembly, said reinforcing core comprising:

a reinforcing core first side and a reinforcing core second side;

a plurality of individual hollow spheres positioned adjacent to one another, said plurality of individual hollow spheres positioned adjacent to one another is configured to realize an allowed and selected degree of rotational movement with respect to one another, said plurality of individual hollow spheres each comprising a hollow sphere outer surface, said plurality of individual hollow spheres further each comprising a hollow sphere outer diameter, said plurality of individual hollow spheres further each comprising a hollow sphere inner diameter and a hollow sphere wall, said hollow sphere wall comprising a hollow sphere outer wall thickness; and

at least one foam material layer segment configured to receive said plurality of individual hollow spheres, said plurality of individual hollow spheres received into a selected position within the at least one foam material layer segment, said plurality of individual hollow spheres positioned within the at least one foam material layer segment, said at least one foam material layer segment in combination with the plurality of individual hollow spheres configured to form the reinforcing core;

wherein said individual hollow spheres each comprise a hollow sphere material, the hollow sphere material having a flexural strength ranging from about 420 MPa to about 470 MPa, a flexural modulus ranging from about 40 GPa to about 50 GPa, a tensile strength ranging from about 680 MPa to about 770 MPa, a tensile modulus ranging from about 47 GPa to about 58 GPa, and a selected density ranging from about 0.7 gm/cm 3 to about 1.2 g/cm 3 ; and

wherein said reinforcing core is configured to sustain a significant degree of out-of-plane movement and manipulation when the reinforcing core assembly is manipulated from a planar sheet orientation into an out-of-plane configuration.

2 . The reinforcing core of claim 1 , further comprising a first adhesive layer adhered to the reinforcing core first side, and a second adhesive layer adhered to the reinforcing core second side, said reinforcing core in combination with the first adhesive layer and in further combination with the second adhesive layer configured to form a reinforcing core assembly.

3 . The reinforcing core of claim 1 , wherein the each of the plurality of individual hollow spheres are interconnected hollow spheres.

4 . The reinforcing core of claim 2 , wherein two or more of the first adhesive layer, the second adhesive layer, and the plurality of individual hollow spheres are co-curable at a co-curing temperature to form a co-cured reinforcing core assembly.

5 . The reinforcing core of claim 4 , said co-curing temperature ranging from about 180° F. to about 350° F.

6 . The reinforcing core of claim 1 , wherein each of the plurality of individual hollow spheres comprises a plurality of additively manufactured to form a sheet of interconnected hollow spheres.

7 . A composite material assembly stack comprising the reinforcing core of claim 1 .

8 . A vehicle comprising the reinforcing core of claim 1 .

9 . An aircraft comprising the reinforcing core of claim 1 .

10 . A panel assembly comprising:

a first facesheet comprising a first facesheet outer surface and a first facesheet inner surface, said first facesheet comprising at least one of a metal material and a composite material;

a second facesheet comprising a second factsheet outer surface and a second facesheet inner surface, said second facesheet comprising at least one of a metal material and a composite material;

a reinforcing core comprising a reinforcing core first side and a reinforcing core second side, said reinforcing core interposed between the first facesheet inner surface and the second facesheet inner surface, said reinforcing core comprising:

a plurality of individual hollow spheres positioned adjacent to one another, each of said plurality of individual hollow spheres positioned adjacent to one another to realize an allowed and selected degree of rotational movement with respect to one another, each of said plurality of individual hollow spheres each comprising a hollow sphere outer surface, said plurality of individual hollow spheres further each comprising a hollow sphere outer diameter, said plurality of individual hollow spheres further each comprising a hollow sphere inner diameter and a hollow sphere wall, said hollow sphere wall comprising a hollow sphere outer wall thickness;

at least one foam material layer segment configured to receive said plurality of individual hollow spheres, said plurality of individual hollow spheres received into a selected position within the at least one foam material layer segment, said plurality of individual hollow spheres positioned within the at least one foam material layer segment, said at least one foam material layer segment in combination with the plurality of individual hollow spheres configured to form the reinforcing core;

a first adhesive layer positioned between the reinforcing core first side and the first facesheet inner surface; and

a second adhesive layer positioned between the reinforcing core second side and the second facesheet inner surface;

wherein said individual hollow spheres each comprise a hollow sphere material, the hollow sphere material having a flexural strength ranging from about 420 MPa to about 470 MPa, a flexural modulus ranging from about 40 GPa to about 50 GPa, a tensile strength ranging from about 680 MPa to about 770 MPa, a tensile modulus ranging from about 47 GPa to about 58 GPa, and a selected density ranging from about 0.7 gm/cm 3 to about 1.2 g/cm 3 ; and

wherein said reinforcing core is configured to sustain a significant degree of out-of-plane movement and manipulation as the reinforcing core assembly is manipulated from a planar sheet orientation into an out-of-plane configuration.

11 . The panel assembly of claim 10 , wherein each of the plurality of hollow spheres comprise a substantially equivalent hollow sphere outer diameter, each of said plurality of hollow spheres further comprising a substantially equivalent hollow sphere inner diameter.

12 . The panel assembly of claim 10 , wherein each of the plurality of hollow spheres are positioned at a selected uniform distance from one another.

13 . The panel assembly of claim 10 , wherein each of the plurality of hollow spheres are interconnected.

14 . The panel assembly of claim 10 , wherein each of the plurality of individual hollow spheres each comprise a hollow sphere outer wall average thickness ranging from about 0.8 μm to about 1.2 μm.

15 . The panel assembly of claim 10 , wherein the first adhesive layer is a first adhesive single film layer, and wherein the second adhesive layer is a second adhesive single film layer.

16 . An aircraft component assembly comprising the panel assembly of claim 10 .

17 . An aircraft comprising the panel assembly of claim 10 .

18 . A method for making a reinforcing core assembly, the method comprising:

incorporating a plurality of hollow spheres into a first foam material layer segment, each of said plurality of individual hollow spheres positioned adjacent to one another to realize an allowed and selected degree of rotational movement with respect to one another, said individual hollow spheres each comprising a hollow sphere outer surface, said individual hollow spheres further each comprising a hollow sphere outer diameter, said individual hollow spheres further each comprising a hollow sphere inner diameter and a hollow sphere wall, said hollow sphere wall comprising a hollow sphere outer wall thickness,

said individual hollow spheres each comprising a hollow sphere material, the hollow sphere material having a flexural strength ranging from about 420 MPa to about 470 MPa, a flexural modulus ranging from about 40 GPa to about 50 GPa, a tensile strength ranging from about 680 MPa to about 770 MPa, a tensile modulus ranging from about 47 GPa to about 58 GPa, and a selected density ranging from about 0.7 gm/cm 3 to about 1.2 g/cm 3 ,

said first foam material layer segment comprising a first foam material layer segment first side and a first foam material layer segment second side;

applying a second foam material layer segment to the plurality of hollow spheres to form a reinforcing core, said reinforcing core comprising a reinforcing core first side and a reinforcing core second side;

applying a first adhesive layer to the reinforcing core first side; and

applying a second adhesive layer to the reinforcing core second side to form the reinforcing core assembly, said reinforcing core assembly comprising the first adhesive layer, the second adhesive layer and the reinforcing core;

wherein said reinforcing core is configured to sustain a significant degree of out-of-plane movement and manipulation as the reinforcing core assembly is manipulated from a planar sheet orientation into an out-of-plane configuration.

19 . The method of claim 18 , wherein the plurality of hollow spheres are positioned adjacent to one another in a substantially singular plane.

20 . The method of claim 18 , further comprising:

additively manufacturing the plurality of hollow spheres.