# US 8,771,575 B2 · Methods and systems for forming reinforced composite articles having variable thickness corners

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- Number: US 8,771,575 B2
- Document ID: US8771575B2
- Status: Granted
- Kind: B2
- Application number: 13/557,693
- Filed: 2012-07-25
- Published: 2013-07-25
- Granted: 2014-07-08
- Earliest claimed: 2011-07-27
- Assignees: Dieffenbacher GmbH Maschinen- und Anlagenbau
- Applicants: Dustin Louis Dequine
- Inventors: Dustin Louis Dequine
- Web page: https://patentgrep.com/patent/US8771575B2

## CPC

- B29D 99/0003: {Producing profiled members, e.g. beams}
- B29C 43/003: {characterised by the choice of material}
- B29C 43/52: Heating or cooling
- B29C 70/207: {arranged in parallel planes of fibres crossing at substantial angles}
- B29C 70/46: using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
- Y10T 428/2419: Fold at edge
- Y10T 428/24264: Particular fold structure [e.g., beveled, etc.]
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method for making parts with variable thickness corners and parts with variable thickness corners are disclosed. The method includes laying up multiple plies to form a tailored blank, associating the blank with a convex and concave die, and applying pressure and heat so that material from at least one of the plies migrates towards a voided corner area formed between the dies.

## Claims

### Claim 1

A method for manufacturing a composite part from a blank having an intermediate ply oriented in a first direction, a first outer ply disposed on a first side of the intermediate ply and oriented transverse to the first direction, and a second outer ply disposed on a second side of the intermediate ply opposite to the first side and oriented transverse to the first direction, the method comprising:
positioning the blank between a convex die and a concave die, with the intermediate ply oriented with fibers generally parallel to a longitudinal direction in which an internal corner of the concave die and an external corner of the convex die extend, and with the first outer ply and the second outer ply oriented with fibers generally transverse to the longitudinal direction,
wherein a radius of the internal corner that forms a corner of the composite part is less than a radius of the external corner that forms the corner of the composite part plus the thickness of a section of the composite part adjacent to the corner of the composite part; and
pressing the blank between the convex die and concave die such that fibers of the intermediate ply migrate into the corner of the composite part and provide the intermediate ply with an increased cross-sectional thickness at the corner of the composite part.

### Claim 2 (depends on 1)

The method of claim 1, wherein the blank comprises resin, and wherein pressing the blank between the convex die and the concave die causes resin of the intermediate ply to migrate toward the corner of the composite part in between the first and second outer plies.

### Claim 3 (depends on 1)

The method of claim 1, wherein the first outer ply faces the concave die and the second outer ply faces the convex die, and wherein the first and second outer plies are positioned at an angle between negative five degrees and five degrees with respect to the longitudinal direction.

### Claim 4 (depends on 3)

The method of claim 3, wherein the blank has a plurality of plies that are oriented with fibers in the first direction and are positioned between the first outer ply and the second outer ply.

### Claim 5 (depends on 4)

The method of claim 4, wherein fibers of each of the plurality of plies migrate into the corner of the composite part.

### Claim 6 (depends on 1)

The method of claim 1, wherein when viewed in a cross-section taken perpendicularly to the longitudinal direction:
the convex die and the concave die are separated by a web gap distance on a web side of the corner of the composite part,
the convex die and the concave die are separated by a flange qap distance on a flange side of the corner of the composite part opposite to the web side of the corner, and
wherein the web gap distance is less than the flange gap distance.

### Claim 7 (depends on 6)

The method of claim 6, wherein the web gap distance is between 0.05% and 4% less than the flange gap distance.

### Claim 8 (depends on 1)

The method of claim 1, wherein the composite part comprises an elongated member, wherein the intermediate ply is oriented with fibers generally parallel to a longitudinal axis of the elongated member, and wherein the first outer ply and the second outer ply are oriented with fibers generally transverse to the longitudinal axis of the elongated member.

### Claim 9 (depends on 1)

The method of claim 1, wherein the intermediate ply comprises a first intermediate ply, wherein the blank further comprises a second intermediate ply between the first outer ply and the second outer ply, and wherein the second intermediate ply is oriented with fibers at an angle to the fibers of the first outer ply and the fibers of the second outer ply.

### Claim 10 (depends on 9)

The method of claim 9, wherein the first intermediate ply is oriented with fibers at approximately 0 degrees to the longitudinal direction, the second outer ply is oriented with fibers at approximately 90 degrees to the longitudinal direction, and the second intermediate ply is oriented with fibers at approximately 45 degrees to the longitudinal direction.

### Claim 11 (depends on 1)

The method of claim 1, further comprising heating the blank.

### Claim 12 (depends on 11)

The method of claim 11, further comprising heating one or both of the convex die and the concave die.

### Claim 13 (depends on 1)

The method of claim 1, wherein pressing the blank between the convex die and the concave die comprises using hydrostatic pressure.

### Claim 14 (depends on 1)

The method of claim 1, wherein the first outer ply contacts the concave die, and wherein the pressing pulls new material of the first outer ply into the internal corner of the concave die and provides the first outer ply with a constant cross-sectional thickness through the corner of the composite part that is substantially equal to cross-sectional thicknesses of the first outer ply in regions adjacent to the corner of the composite part.

### Claim 15

A method for manufacturing a composite part from a blank, the method comprising:
positioning the blank between a convex die and a concave die,
wherein the blank has a first outer ply contacting the concave die and oriented in a first direction, an intermediate ply oriented in a second direction, and a second outer ply contacting the convex die and oriented in a third direction,
wherein the intermediate ply is disposed between the first outer ply and the second outer ply,
wherein the second direction is different from the first direction and the third direction,
wherein the intermediate ply is oriented with fibers generally parallel to a longitudinal direction in which an internal corner of the concave die and an external corner of the convex die extend, and
wherein a radius of the internal corner that forms a corner of the composite part is less than a radius of the external corner that forms the corner of the composite part plus the thickness of a section of the composite part adjacent to the corner of the composite part; and
pressing the blank between the convex die and concave die such that fibers of the intermediate ply migrate into the corner of the composite part to increase the thickness of a portion of the intermediate ply in the corner of the composite part and such that the thickness of a portion of the first outer ply in the corner of the composite part does not substantially change.

### Claim 16 (depends on 15)

The method according to claim 15, wherein the blank further comprises a second intermediate ply oriented with fibers in the second direction, wherein the second intermediate ply is disposed between the first intermediate ply and the second outer ply, and wherein fibers of the second intermediate ply migrate into the corner of the composite part when the blank is pressed between the convex die and the concave die to increase the thickness of a portion of the second intermediate ply in the corner of the composite part.

### Claim 17 (depends on 15)

The method according to claim 15, wherein pressing the blank between the convex die and the concave die comprises using hydrostatic pressure.

### Claim 18 (depends on 15)

The method according to claim 15, wherein pressing generates a structural member that is thicker at the corners than in the adjacent non-corner regions.

### Claim 19 (depends on 15)

The method according to claim 15, wherein the first direction is angled with respect to the second direction by an angle in the range between 10 degrees and 80 degrees.

### Claim 20 (depends on 15)

The method according to claim 15, wherein the first outer ply and the second outer ply are oriented at any angle between 45 degrees and 90 degrees or between negative 45 degrees and negative 90 degrees with respect to the longitudinal direction.

### Claim 21 (depends on 20)

The method according to claim 20, wherein the intermediate ply is generally oriented with fibers at an angle between negative five degrees and five degrees with respect to the longitudinal direction.

### Claim 22 (depends on 15)

The method according to claim 15, wherein the first outer ply comprises a composite material including resin and reinforcing fibers, and wherein the relative locations of the reinforcing fibers disposed in the corner of the composite part changes as the blank is pressed.

### Claim 23 (depends on 15)

The method according to claim 15, wherein the first outer ply is pulled in from outside the convex and concave dies and conformed to the concave die.

### Claim 24 (depends on 15)

The method according to claim 15, wherein the concave die is made of material comprising one of metal and metal alloy.

### Claim 25 (depends on 15)

The method according to claim 15, wherein the concave die is one of coated and plated with a non-stick material.

### Claim 26 (depends on 15)

The method according to claim 15, wherein the convex die and concave die provide a hard-tooled gap on one side of a variable-thickness corner that is less than a hard-tooled gap on the other side of the variable-thickness corner.

### Claim 27

A method for manufacturing a composite part from a blank having a first outer ply, a second outer ply, and an intermediate ply in between the first outer ply and the second outer ply, the method comprising:
positioning the blank between a convex die and a concave die, with the intermediate ply oriented with fibers generally parallel to a longitudinal direction in which an internal corner of the concave die extends,
wherein the first outer ply and the second outer ply are oriented with fibers generally transverse to the longitudinal direction,
wherein the convex die has an external corner that extends in the longitudinal direction and faces the internal corner of the concave die,
wherein the convex die and the concave die are separated by a gap distance at straight portions of the convex die and the concave die adjacent to the internal and external corners, and
wherein the internal corner of the concave die has a radius that is less than: a radius of the external corner of the convex die plus the gap distance; and
pressing the blank between the convex die and the concave die such that fibers and resin of the intermediate ply migrate into a corner of the composite part created between the external corner of the convex die and the internal corner of the concave die, so as to provide the intermediate ply with an increased cross-sectional thickness at the corner of the composite part.

### Claim 28 (depends on 27)

The method of claim 27, wherein the composite part comprises a c-channel,
wherein the gap distance comprises a first gap distance on a web side of the internal and external corners,
wherein the convex die and the concave die are separated by a second gap distance on a flange side of the internal and external corners opposite to the web side, and
wherein the first gap distance is less than the second gap distance.

### Claim 29 (depends on 28)

The method of claim 28, wherein the first gap distance is between 0.05% and 4% less than the second gap distance.

### Claim 30 (depends on 27)

The method of claim 27, wherein the fibers of the first outer ply and the second outer ply are oriented at approximately 90 degrees to the longitudinal direction.