Method for composite truss manufacturing

Patent metadata

Field	Value
Publication number	US-11945139-B2
Application number	US-202117403271-A
Country	US
Kind code	B2
Filing date	Aug 16, 2021
Priority date	Aug 14, 2020
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

Methods for fabricating fiber-composite truss structures comprise a) individually molding multiple unit cells of a given size, and subsequently fusing them together in a repeating pattern, b) cross members are consolidated with longerons while maintaining continuity of fiber in the longerons, and c) compression-molded truss components are unioned to continuous fiber beams by means of mechanically interlocking joints.

First claim

What is claimed:

1. A method comprising:
forming, via compression molding, a first unit cell having:
(i) a first, second, and third longeron, each longeron having a first end and a second end, a distance between the first end and the second end defining a length of each longeron and a length of the first unit cell, each longeron comprising a plurality of continuous, unidirectionally aligned fibers having a length substantially equal to the length of the first unit cell, and wherein the three longerons are arranged in a three-dimensional chevron shape, wherein the first longeron is located at an apex of the chevron shape, and wherein a thickness of the second longeron and the third longeron is about one-half of the thickness of the first longeron;
(ii) a plurality of cross members, each cross member having a first end and second end, a distance between the first and second end of a respective cross member defining a length thereof, each cross member comprising a plurality of continuous, unidirectionally aligned fibers having a length substantially equal to the length of the respective cross member, wherein:
(a) the first end of each cross member couples to a first longerons, and wherein, at the first end of the cross members, at least some of the fibers overlap at least some of the fibers in the first longeron,
(b) the second end of each cross member couples to either the second or the third longeron, and wherein at the second end of the cross members, at least some of the fibers overlap at least some of the fibers in the respective second or third longeron to which the second end of each cross member is coupled;

forming, via compression molding, a second unit cell, the second unit cell having first, second, and third longerons arranged in the chevron shape, wherein;
(i) the first longeron in the second unit cell is located at the apex of the chevron shape,
(ii) a thickness of the first longeron in the second unit cell is equal to the thickness of the first longeron in the first unit cell, and
(iii) a thickness of the second longeron and the third longeron in the second unit cell is about one-half of the thickness of the first longeron;

forming, in the second and third longerons of the first and second unit cell, complementary mechanical mating features that facilitate alignment and coupling of the first unit cell to the second unit cell; and
thermally bonding, along the length thereof, the second and third longeron of the first unit cell to the second and third longerons, respectively, of the second unit cell, thereby forming a first truss structure having four longerons of about equal thickness and a quadrilateral shape.

2. A method comprising:
forming, via compression molding, a first unit cell having:
(i) a first, second, and third longeron, each longeron having a first end and a second end, a distance between the first end and the second end defining a length of each longeron and the length of the first unit cell, each longeron comprising a plurality of continuous, unidirectionally aligned fibers having a length substantially equal to the length of the first unit cell, and wherein the three longerons are arranged in a three-dimensional chevron shape, wherein the first longeron is located at an apex of the chevron shape, and wherein a thickness of the second longeron and the third longeron is about one-half of the thickness of the first longeron;
(ii) a plurality of cross members, each cross member having a first end and second end, a distance between the first and second end of a respective cross member defining a length thereof, each cross member comprising a plurality of continuous, unidirectionally aligned fibers having a length substantially equal to the length of the respective cross member, wherein:
(a) the first end of each cross member couples to the first longeron, and wherein, at the first end of the cross members, at least some of the fibers overlap at least some of the fibers in the first longeron,
(b) the second end of each cross member couples to either the second or the third longeron, and wherein at the second end of the cross members, at least some of the fibers overlap at least some of the fibers in the respective second or third longeron to which the second end of each cross member is coupled;

forming, via compression molding, a second unit cell, the second unit cell having first, second, and third longerons arranged in the chevron shape, wherein:
(i) the first longeron in the secnd unit cell is located at the apex of the chevron shape,

(ii) a thickness of the first longeron in the second unit cell is equal to the thickness of the first longeron in the first unit cell, and
(iii) a thickness of the second longeron and the third longeron in the second unit cell is about one-half of the thickness of the first longeron; and

thermally bonding, along the length thereof, the second and third longeron of the first unit cell to the second and third longerons, respectively, of the second unit cell, wherein, during bonding, fiber engagement across an interface of the first unit cell and the second unit cell is established, wherein fibers from associated with the second and third longeron of at least one of the first or second unit cells intermingle with fibers associated with the second and third longerons of the other of the second or first unit cell, thereby forming a first truss structure having four longerons of about equal thickness and a quadrilateral shape.

3. the method of claim 2 wherein the second and third longerons of the first or second unit cell include fibers that sare shorter than the fibers that are aligned with a long axis of the longerons, wherein the shorter fibers do not align with the long axis of the longerons,
the method comprising intermingling, during thermal bonding, the shorter fibers from the second and third longerons of the first unit cell with the shorter fibers from the second and third longerons of the second unit cell.

4. The method of claim 2 wherein fiber engagement across the interface is established by a technique selected from the group consisting of creating foldable tabs in the second and/or third longerons, providing local flowable fibers in the second and/or third longerons, and providing consolidation rivets in the second and/or third longerons.

5. The method of claim 1 comprising:
providing a second truss structure having four longerons of substantially equal thickness and a quadrilateral shape that is substantially the same as the first truss structure;
thermally bonding a first end of each of the four longerons of the first truss structure to a first end of each of the four longerons of the second truss structure, thereby extending a length of the truss structure formed by the joinder of the first and second unit cells.

6. The method of claim 2 comprising:
providing a second truss structure having four longerons of substantially equal thickness and a quadrilateral shape that is substantially the same as the first truss structure;
thermally bonding a first end of each of the four longerons of the first truss structure to a first end of each of the four longerons of the second truss structure, thereby extending a length of the truss structure formed by the joinder of the first and second unit cells.

Assignees

• Arris Composites Inc

Inventors

• Escowitz Ethan
• Davidson Erick
• Perkins J Scott
• Reese Riley

Classifications

• B29C43/224 Primary

  having a profiled section, e.g. tubes, rods · CPC title

• B29C43/003

  characterised by the choice of material · CPC title

• B29C70/205

  the structure being shaped to form a three-dimensional configuration · CPC title

• B29C70/34

  and shaping or impregnating by compression {, i.e. combined with compressing after the lay-up operation} · CPC title

• B29K2105/101

  Oriented · CPC title