Methods of producing a cellular structure

Patent metadata

Field	Value
Publication number	US-11020909-B2
Application number	US-201816165880-A
Country	US
Kind code	B2
Filing date	Oct 19, 2018
Priority date	Oct 20, 2017
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A method of producing a cellular structure via an additive manufacturing technique includes the steps of: providing a feedstock material to an additive manufacturing printer device; dispensing the feedstock material from the printer device; and controlling the dispensing of the feedstock material to form at least one layer of the cellular structure according to a first predetermined gradient. In some aspects, the cellular structure comprises an array of cells surrounded, respectively, by walls, and arranged to create a non-uniform relative density and/or cell geometry across a width and/or a height of the cellular structure. An article of manufacture produced by such methods includes a cellular structure configured to produce a controlled collapse with selectable dynamic stiffness characteristics by altering the distribution and geometry of cells within the cellular structure, while being able to maintain a substantially similar static stiffness characteristic.

First claim

What is claimed is:

1. A method of producing a cellular structure via an additive manufacturing technique, the method comprising:
providing a feedstock material to an additive manufacturing printer device;
dispensing the feedstock material from the printer device; and
controlling the dispensing of the feedstock material to form at least one layer of the cellular structure according to a first predetermined gradient;
wherein the at least one layer comprises an array of cells surrounded, respectively, by walls, and arranged to create a non-uniform relative density and/or cell geometry across a width and/or a length of the cellular structure, the width and the length being oriented substantially orthogonally to a depth of the cellular structure.

2. The method of claim 1 , wherein the feedstock material is selected from the group consisting of one or more of acrylonitrile butadiene styrene (ABS), poly(lactic acid) (PLA), a thermoplastic material, epoxies, elastomers, reactive polymer systems, including (polyurethane and polyurea, preceramic polymer resins, ceramics, metals, fiber composites, bio-materials, gels, conductive inks, and battery materials.

3. The method of claim 1 , wherein the array of cells comprises cells having a shape of one or more of a triangle, a square, a rectangle, a parallelogram, a kagome pattern, a hexagon, an octagon, and an hourglass.

4. The method of claim 1 , wherein the relative density of the at least one layer increases from a first side of the at least one layer to a second side of the at least one layer.

5. The method of claim 1 , wherein at least some of the walls are arranged between adjacent cells of the array of cells.

6. The method of claim 1 , wherein the array of cells is arranged according to a shift function to create the non-uniform relative density and/or cell geometry across the width and/or the length of the at least one layer.

7. The method of claim 6 , wherein the shift function is a non-linear shift function, such that each row and/or column of cells in the array of cells has a different relative density and/or cell geometry from an adjacent row and/or column of cells in the array of cells.

8. The method of claim 7 , wherein the at least one layer has a lower and/or higher relative density in a center region of the at least one layer than at a perimeter region of the at least one layer.

9. The method of claim 6 , wherein the shift function is a piece-wise linear shift function, such that the at least one layer comprises at least first and second regions,
wherein the array of cells comprises a first subarray of cells and a second subarray of cells,
wherein the first subarray of cells has a first relative density and is arranged in the first region, and
wherein the second subarray of cells has a second relative density and is arranged in the second region.

10. The method of claim 9 , wherein the first relative density is different from the second relative density.

11. The method of claim 9 , wherein the first subarray of cells comprises cells that are a different size, aspect ratio, and/or shape than cells in the second subarray of cells.

12. The method of claim 6 , wherein controlling the dispensing of the feedstock material comprises:
arranging at least one attractor node and/or at least one detractor node within the first predetermined gradient;
selecting an amplitude associated with the shift function to determine a degree of non-linearity of a distribution of cells within the array of cells; and
applying the shift function to generate a non-uniform distribution of cells within the array of cells.

13. The method of claim 12 , wherein the shift function comprises a piece-wise linear shift function, a quadratic shift function, a sinusoidal shift function, an exponential shift function, or any combination thereof.

14. The method of claim 1 , comprising controlling the dispensing of the feedstock to form a plurality of subsequent layers of the cellular structure according to respective predetermined gradients.

15. The method of claim 14 , wherein a relative density and/or cell geometry of an array of cells of a first layer has a different gradient from a relative density and/or cell geometry of an array of cells of a second layer.

16. The method of claim 1 , comprising varying a speed of a nozzle of the printer device as the feedstock material is dispensed to produce walls having variable thickness.

17. The method of claim 1 , wherein the additive manufacturing technique comprises one or more of a fused deposition modeling (FDM™) technique, a fused filament fabrication (FFF) technique, a big area additive manufacturing (BAAM) technique, a robocasting technique, a paste extrusion technique, and/or a direct ink writing (DIW) technique.

18. The method of claim 1 , wherein the cellular structure comprises a single layer, wherein the at least one layer is the single layer, and wherein the at least one layer is dispensed onto a substrate.

19. The method of claim 18 , wherein the substrate comprises woven or non-woven fabric, felt, polymer film, paper, and/or foil.

20. The method of claim 1 , comprising:
defining a three-dimensional domain corresponding to a three-dimensional cellular structure;
arranging a plurality of nodes throughout the domain;
applying a shift function in at least one direction of the domain so that the nodes have a non-uniform distribution in the at least one direction; and
interconnecting the nodes to form individual three-dimensional cells within the cellular structure.

21. The method of claim 20 , wherein interconnecting the nodes comprises connecting adjacent nodes with struts so that the cellular structure is of an open cell type.

22. The method of claim 20 , wherein the individual cells are physically segregated from each other by walls so that the cellular structure is of a closed cell type.

Assignees

• Univ Tennessee Res Found

Inventors

• Compton Brett Gibson
• Goin Michael James
• Shams Hesam
• Shylo Oleg

Classifications

• B32B3/12

  characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B33Y80/00 Primary

  Products made by additive manufacturing · CPC title

• C08J9/26

  by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out · CPC title

• B29C64/10

  Processes of additive manufacturing · CPC title