Micro-truss based energy absorption apparatus

• US 9,116,428 B1
• Filed: 06/01/2009
• Issued: 08/25/2015
• Est. Priority Date: 06/01/2009
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Jacobsen, Alan J., Carter, William B., Cumberland, Robert W.
• Primary Examiner(s): Johnson, Stephen M
• Application Number:
  US12/455,449
• Time in Patent Office: 2,276 Days
• Field of Search: 89/360.2, 385/46, 428/116
• US Class Current: 1/1
• CPC Class Codes: B32B 3/12 characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure
• CPC Class Codes: F41H 5/04 composed of more than one layer outerwear resistant to mechanical aggressions A41D31/24; layered products B32B; shaping reinforced articles B29C67/00
• CPC Class Codes: F41H 5/0471 Layered armour containing fibre- or fabric-reinforced layers in combination with ceramic layers F41H5/0428, with metal layers F41H5/0457
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/09 characterised by structural details, e.g. supports, auxiliary layers supports for printing plates in general B41N

Abstract

A micro-truss based blast protection apparatus. In one embodiment, the blast protection apparatus includes a three-dimensional (3D) ordered truss core between a first face plate and a second face plate. The 3D ordered truss core includes first truss elements defined by first self-propagating polymer waveguides and extending along a first direction, second truss elements defined by second self-propagating polymer waveguides and extending along a second direction, and third truss elements defined by third self-propagating polymer waveguides and extending along a third direction. The first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material. The first, second, and third truss elements define an open space for providing a densification in response to a force applied to the first face plate and/or the second face plate, and the 3D ordered truss core is self-supporting.

Claims

1. A micro-truss based structural apparatus intended to absorb an impact energy upon impact comprising:

a first face plate;

a second face plate; and

a first three-dimensional ordered truss core between the first face plate and the second face plate, and

wherein the first three-dimensional ordered truss core comprising;

a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction;

a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and

a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction;

wherein the first, second, and third truss elements interpenetrate each other at a plurality of first nodes to form a first continuous material;

wherein the first, second, and third truss elements define a first open space enabling densification in response to a force applied to at least one of the first face plate or the second face plate; and

wherein the impact energy is absorbed by the densification of the first three-dimensional ordered truss core.

2. The micro-truss based structural apparatus intended to absorb energy upon impact of claim 1, further comprising a second three-dimensional ordered truss core,

wherein the second face plate is between the first three-dimensional ordered truss core and the second three-dimensional ordered truss core, and

wherein the second three-dimensional ordered truss core comprises:

a plurality of fourth truss elements defined by a plurality of fourth self-propagating polymer waveguides and extending along a fourth direction;

a plurality of fifth truss elements defined by a plurality of fifth self-propagating polymer waveguides and extending along a fifth direction; and

a plurality of sixth truss elements defined by a plurality of sixth self-propagating polymer waveguides and extending along a sixth direction;

wherein the fourth, fifth, and sixth truss elements interpenetrate each other at a plurality of second nodes to form a second continuous material;

wherein the fourth, fifth, and sixth truss elements define a second open space for enabling densification in response to a force applied thereto; and

wherein the impact energy is further absorbed by densification of the second three-dimensional ordered truss core.

3. The micro-truss based structural apparatus of claim 2, wherein the first three-dimensional ordered truss core has a first three-dimensional pattern, and wherein the second three-dimensional ordered truss core has a second three-dimensional pattern differing from the first three-dimensional pattern.

4. The micro-truss based structural apparatus of claim 2, further comprising a third three-dimensional ordered truss core,

wherein the second three-dimensional ordered truss core is between the second face plate and the third three-dimensional ordered truss core, and

wherein the third three-dimensional ordered truss core comprises:

a plurality of seventh truss elements defined by a plurality of seventh self-propagating polymer waveguides and extending along a seventh direction;

a plurality of eighth truss elements defined by a plurality of eighth self-propagating polymer waveguides and extending along an eighth direction; and

a plurality of ninth truss elements defined by a plurality of ninth self-propagating polymer waveguides and extending along a ninth direction;

wherein the seventh, eighth, and ninth truss elements interpenetrate each other at a plurality of third nodes to form a third continuous material;

wherein the seventh, eighth, and ninth truss elements define a third open space for enabling densification in response to a force applied thereto; and

wherein the impact energy is further absorbed by densification of the third three-dimensional ordered truss core.

5. The micro-truss based structural apparatus of claim 4, wherein the three-dimensional ordered truss core has a first three-dimensional pattern, wherein the second three-dimensional ordered truss core has a second three-dimensional pattern differing from the first three-dimensional pattern, and wherein the third three-dimensional ordered truss core has a third three-dimensional pattern differing from at least one of the first three-dimensional pattern or the second three-dimensional pattern.

6. The micro-truss based structural apparatus of claim 1, wherein the first, second, and third truss elements are adapted to provide the first three-dimensional ordered truss core with an compression-dominated behavior of the truss elements.

7. The micro-truss based structural apparatus of claim 1, wherein the first, second, and third truss elements are adapted to provide the first three-dimensional ordered truss core with a compressive elastic modulus directly proportional to both a density of the first three-dimensional ordered truss core and a modulus of a solid material portion of the first three-dimensional ordered truss core.

8. The micro-truss based structural apparatus of claim 7, wherein each of the first, second, and third truss elements has a truss diameter between about 10 microns and about 5 mm and has a length between two adjacent ones of the first nodes that is between about 5 and 15 times the truss diameter.

9. The micro-truss based structural apparatus of claim 7, wherein the first three-dimensional ordered truss core has between about ½

unit cell of the first three-dimensional ordered truss core and about 5 unit cells of the first three-dimensional ordered truss core through its thickness.

10. The micro-truss based structural apparatus of claim 7, wherein the first, second, and third truss elements are adapted to provide the first three-dimensional ordered truss core with a compressive elastic modulus (E) determined by:

E=C_EE_s(ρ

/ρ

_s)^r

wherein ρ

is a density of the first three-dimensional ordered truss core, ρ

_s is a density of a solid material portion of the first three-dimensional ordered truss core, E_s is a modulus of the solid material portion of the first three-dimensional ordered truss core, and C_E and r are scaling parameters related to the first three-dimensional ordered truss core.

11. A micro-truss based structural apparatus intended to absorb energy upon impact comprising:

a macro-scale truss structure and a micro-scale truss structure,

wherein the macro-scale truss structure comprises a plurality of macro-scale truss elements;

wherein the micro-scale truss structure comprises a plurality of micro-scale truss elements,

wherein the plurality of macro-scale truss elements are composed of the plurality of micro-scale truss elements,

wherein the plurality of micro-scale truss elements of the micro-scale truss structure comprise;

a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction;

a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and

a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction;

wherein the first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material, and

wherein the first, second, and third truss elements define an open space enabling densification of the macro-scale truss structure or the micro-scale truss structure.

12. The micro-truss based structural apparatus of claim 11, wherein the plurality of macro-scale truss elements of the macro-scale truss structure define a second open space for enabling a second densification.

13. The micro-truss based structural apparatus of claim 11, further comprising:

a first face plate;

a second face plate;

wherein the plurality of micro-scale truss elements of the micro-scale truss structure are between the first face plate and the second face plate.

14. The micro-truss based structural apparatus of claim 11, wherein the plurality of macro-scale truss elements are configured to be a plurality of hexagonal cores.

15. The micro-truss based structural apparatus of claim 11, wherein the plurality of macro-scale truss elements are configured to be a plurality of V-shaped structures.

16. The micro-truss based structural apparatus of claim 15, further comprising:

a third face plate;

a fourth face plate;

wherein the plurality of V-shaped structures are between the third face plate and the fourth face plate.

17. A micro-truss based structural apparatus to absorb energy of an impact comprising:

a hierarchical structure;

wherein the hierarchical structure comprises a smaller scale micro-truss filling the open volume of a larger-scale micro-truss, the smaller scale micro-truss being defined by a plurality of first self-propagating photopolymer waveguides and the larger scale micro-truss being defined by a plurality of second self-propagating photopolymer waveguides.

18. A method of absorbing an energy, the method comprising:

positioning a first three-dimensional ordered truss core between a first face plate and a second face plate, the first three-dimensional ordered truss core comprising;

a plurality of first truss elements defined by a plurality of first self-propagating polymer waveguides and extending along a first direction;

a plurality of second truss elements defined by a plurality of second self-propagating polymer waveguides and extending along a second direction; and

a plurality of third truss elements defined by a plurality of third self-propagating polymer waveguides and extending along a third direction,

wherein the first, second, and third truss elements interpenetrate each other at a plurality of first nodes to form a first continuous material, and

wherein the first, second, and third truss elements define a first open space;

positioning at least one of the first face plate or the second face plate to allow the energy to impact the at least one of the first face plate or the second face plate; and

absorbing the energy by densifying the first three-dimensional ordered truss core through collapsing of the first open space.

19. The method of claim 18, wherein the first, second, and third truss elements are adapted to provide the first three-dimensional ordered truss core with a compressive elastic modulus directly proportional to both a density of the first three-dimensional ordered truss core and a modulus of a solid material portion of the first three-dimensional ordered truss core.

20. The method of claim 19, wherein each of the first, second, and third truss elements has a truss diameter between about 10 microns and about 5 mm and has a length between two adjacent ones of the first nodes that is between about 5 and 15 times the truss diameter.

21. The method of claim 19, wherein the first three-dimensional ordered truss core has between about ½

unit cell of the first three-dimensional ordered truss core and about 5 unit cells of the first three-dimensional ordered truss core through its thickness.

22. The method of claim 19, wherein the first, second, and third truss elements are adapted to provide the first three-dimensional ordered truss core with a compressive elastic modulus (E) determined by:

E=C_EE_s(ρ

/ρ

_s)^r

wherein ρ

is a density of the first three-dimensional ordered truss core, ρ

_s is a density of a solid material portion of the first three-dimensional ordered truss core, E_s is a modulus of the solid material portion of the first three-dimensional ordered truss core, and C_E and r are scaling parameters related to the first three-dimensional ordered truss core.

23. The method of claim 18, further comprising:

positioning the second plate between the first three-dimensional ordered truss core and a second three-dimensional ordered truss core, the second three-dimensional ordered truss core comprising;

a plurality of fourth truss elements defined by a plurality of fourth self-propagating polymer waveguides and extending along a fourth direction;

a plurality of fifth truss elements defined by a plurality of fifth self-propagating polymer waveguides and extending along a fifth direction; and

a plurality of sixth truss elements defined by a plurality of sixth self-propagating polymer waveguides and extending along a sixth direction,

wherein the fourth, fifth, and sixth truss elements interpenetrate each other at a plurality of second nodes to form a second continuous material, and

wherein the fourth, fifth, and sixth truss elements define a second open space; and

further absorbing the impact energy by densifying the second three-dimensional ordered truss core through collapsing of the second open space.

24. The method of claim 23, further comprising:

positioning the second three-dimensional ordered truss core between the second face plate and a third three-dimensional ordered truss core, the third three-dimensional ordered truss core comprising;

a plurality of seventh truss elements defined by a plurality of seventh self-propagating polymer waveguides and extending along a seventh direction;

a plurality of eighth truss elements defined by a plurality of eighth self-propagating polymer waveguides and extending along an eighth direction; and

a plurality of ninth truss elements defined by a plurality of ninth self-propagating polymer waveguides and extending along a ninth direction,

wherein the seventh, eighth, and ninth truss elements interpenetrate each other at a plurality of third nodes to form a third continuous material, and

wherein the seventh, eighth, and ninth truss elements define a third open space; and

further absorbing the impact energy by densifying the third three-dimensional ordered truss core through collapsing of the third open space.