Granular dynamically strengthened structures

Patent metadata

Field	Value
Publication number	US-11560685-B1
Application number	US-202117354795-A
Country	US
Kind code	B1
Filing date	Jun 22, 2021
Priority date	Jun 24, 2020
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

Exemplary inventive practice provides a structure that is attributed with superior resistance to loading. For example, an inventive structure includes two coaxial axisymmetric (e.g., cylindrical) shells and a granulation-filled matrix material occupying the peripheral space between the shells. According to some inventive embodiments, the granulation-filled matrix material has a loading-responsive matrix (e.g., shear-thickening fluid or highly rate-sensitive polymer) and granules dispersed therein. When the inventive structure encounters pressure loading at its exterior shell, the consistency of the loading-responsive matrix becomes thicker or firmer and thereby promotes, among the granules, interactive mechanisms (e.g., friction and/or arching) that reinforce the granulation-filled matrix material. According to some inventive embodiments, the granulation-filled matrix material has a magnetic-field-responsive matrix and magnetizable granules dispersed therein, and is magnetically fortified via application of a magnetic field (e.g., continuously applied where the matrix is magnetorheological fluid, or temporarily applied where the matrix is rheological fluid containing diamagnetic particles).

First claim

What is claimed is:

1. A structure comprising an axisymmetric body and a granularly filled matrix material, said axisymmetric body characterized by an interior space, said granularly filled matrix material confined in said interior space and including a matrix and a plurality of granules dispersed in said matrix, wherein:
said matrix is thickened or hardened in response to subjection of said structure to loading;
said structure is dynamically strengthened in association with said thickening or hardening of said matrix;
said matrix is selected from the group consisting of a shear-thickening fluid and a strain-rate-sensitivity-hardening elastomer;
if said matrix is a shear-thickening fluid, then said matrix is thickened in response to said subjection of said structure to said loading;
if said matrix is a strain-rate-sensitivity-hardening elastomer, then said matrix is hardened in response to said subjection of said structure to said loading.

2. The structure of claim 1 wherein said dynamic strengthening of said structure by said granularly filled matrix is characterized by increased frictional forces between at least some said granules and increased arching forces between at least some said granules, and wherein said increased frictional forces and said increased arching forces are concomitant said thickening or hardening of said matrix.

3. The structure of claim 2 wherein at least some said granules are magnetized, and wherein a magnetic attraction between at least some said granules represents a cohesive force that enhances said dynamic strengthening of said structure.

4. The structure of claim 3 wherein:
said cohesive force is a first cohesive force;
at least a portion of said axisymmetric body is magnetized;
a magnetic attraction between said at least a portion of said axisymmetric body and said at least some said granules represents a second cohesive force that enhances said dynamic strengthening of said structure.

5. A structure comprising two hollow cylinders and a granularly filled matrix material, said two hollow cylinders being characterized by different diameters and being coaxially situated so as to define an annular cylindrical space therebetween, said granularly filled matrix material at least substantially occupying said annular cylindrical space and including a matrix and a plurality of granules dispersed in said matrix, wherein said matrix undergoes a physical change in response to subjection of said structure to loading, and wherein a strengthening of said structure by said granularly filled matrix material is associated with said physical change undergone by said matrix.

6. The structure of claim 5 wherein said loading is pressure loading, and wherein said strengthening of said structure increases resistance of said structure to said pressure loading.

7. The structure of claim 5 wherein said two hollow cylinders are an inner said hollow cylinder and an outer said hollow cylinder, said inner hollow cylinder has an outside cylindrical surface, said outer hollow cylinder has an inside cylindrical surface, and said annular cylindrical space is bounded by said outside cylindrical surface and said inside cylindrical surface.

8. The structure of claim 5 wherein said structure is characterized by a geometric longitudinal axis and two axial-longitudinal ends, and wherein said structure further comprises two end-closures respectively situated at said two axial-longitudinal ends.

9. The structure of claim 5 wherein:
said matrix is a material selected from the group consisting of shear-thickening fluid and strain-rate-sensitivity-hardening elastomer;
if said matrix is a shear-thickening fluid, then: said physical change undergone by said matrix includes increased viscosity of said matrix; said strengthening of said structure by said granularly filled matrix includes increased frictional forces between at least some said granules and increased arching forces between at least some said granules, wherein said increased frictional forces and said increased arching forces are concomitant said increased viscosity of said matrix;
if said matrix is a strain-rate-sensitivity-hardening elastomer, then: said physical change undergone by said matrix includes increased hardness of said matrix; said strengthening of said structure by said granularly filled matrix includes increased frictional forces between at least some said granules and increased arching forces between said granules, said increased frictional forces and said increased arching forces being concomitant said increased hardness of said matrix.

10. The structure of claim 5 wherein:
said matrix is a shear-thickening fluid;
said matrix thickens in response to said subjection of said structure to said pressure loading;
an interactive change occurs between at least some said granules, said interactive change being associated with said thickening of said matrix;
said interactive change includes at least one of increased frictional forces between at least some said granules and increased arching forces between at least some said granules.

11. The structure of claim 5 wherein:
said matrix is a shear-thickening fluid;
said matrix thickens in response to said subjection of said structure to said pressure loading;
increased frictional forces between at least some said granules and increased arching forces between at least some said granules are associated with said thickening of said matrix.

12. The structure of claim 11 wherein at least some said granules are magnetized granules, and wherein alignment forces between at least some said granules are associated with a magnetic attraction between at least some said granules.

13. The structure of claim 11 wherein:
at least some said granules are magnetized granules;
at least one said hollow cylinder is a magnetized hollow cylinder;
alignment forces between at least some said granules are associated with a magnetic attraction between at least some said granules, and with a magnetic attraction between said at least one hollow cylinder and at least some said granules.

14. The structure of claim 5 wherein:
said matrix is a strain-rate-sensitivity-hardening elastomer;
said matrix hardens in response to said subjection of said structure to said pressure loading;
increased frictional forces between at least some said granules and increased arching forces between at least some said granules are associated with said hardening of said matrix.

15. The structure of claim 14 wherein at least some said granules are magnetized granules, and wherein alignment forces between at least some said granules are associated with a magnetic attraction between at least some said granules.

16. The structure of claim 14 wherein:
at least some said granules are magnetized granules;
at least one said hollow cylinder is a magnetized hollow cylinder;
alignment forces between at least some said granules are associated with a magnetic attraction between at least some said granules, and with a magnetic attraction between said at least one hollow cylinder and at least some said granules.

17. A structure comprising a hollow cylinder and a granularly filled matrix, said hollow cylinder defining a cylindrical space therein, said granularly filled matrix at least substantially occupying said cylindrical space and including a matrix and a plurality of granules dispersed in said matrix, wherein said matrix undergoes a physical change in response to subjection of said structure to loading, and wherein a strengthening of said structure by said granularly filled matrix is associated wi

Assignees

• Us Navy

Inventors

• Dudt Philip J
• Nasrin H John
• Balsara Hiren D

Classifications

• E02B2017/0056

  Platforms with supporting legs · CPC title

• E02D27/52 Primary

  Submerged foundations {, i.e. submerged in open water (E02D27/12 - E02D27/24 take precedence)} · CPC title

• E02D2300/0079

  Granulates · CPC title

• E02D2300/0001

  Rubbers · CPC title

• E02D2200/1685

  cylindrical · CPC title