Patent US4820567A successfully refreshed from Google Patents.
US4820567A
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Microcrack resistant fiber reinforced resin matrix composite laminates
Assignee: RTX Corp
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Filing: 1986-10-22
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Granted: 1989-04-11
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Expires: 2006-10-22
Abstract
Abstract A microcrack resistant graphite fiber reinforced high temperature resin matrix composite laminate is disclosed. The laminate comprises layers having the fiber reinforcement in parallel alignment within each layer. The layers are arranged such that the fibers are oriented at 0° and 90° (±10°) in alternating layers. The specific number of plies per layer is selected so as to produce microcrack resistance. A method for making a microcrack resistant graphite fiber reinforced high temperature resin matrix composite laminate is also disclosed.
Inventors
- 👤 Daniel A. Scola
- 👤 David J. Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:16
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/02; B32B5/12; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B29C70/20; B29C70/202; B32B5/22; B32B5/24; B32B5/26; B32B7/00; B32B7/03; B29C2793/00; B29C2793/0081; B29C70/28; B29C70/30; B29K; B29K2105/00; B29K2105/24; B29K2307/00; B32B38/00; B32B2038/0052; B32B2038/0072; B32B2262/00; B32B2262/10; B32B2262/106; B32B2305/00; B32B2305/08; B32B2307/00; B32B2307/50; B32B2307/54; B32B2307/582; B32B2307/5825; B32B2605/00; B32B2605/08; B32B2605/18; Y; Y10; Y10S; Y10S428/00; Y10S428/902; Y10T; Y10T428/00; Y10T428/24; Y10T428/24058; Y10T428/24124; Y10T428/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
198 words
A composite laminate, comprising a plurality of plies of graphite fiber reinforced resin, having the graphite fibers aligned in substantially unidirectional orientation within each ply, and having the plies aligned in layers and laid up in the laminate according to the formula: (A.sub.x B.sub.y A.sub.x).sub.n wherein A and B denote the orientation of the fibers in successive layers as the angular displacement of the fiber direction relative to a reference direction of 0°, and x and y denote the number of plies comprising each of the successive layers, and n denotes the number of times the three-layer unit (A x B y A x ) is repeated in the laminate, and A=90°±10° B=0° x=2, 3, 4 or 5 y=7, 8 or 9 if x=2, and 2, 7, 8 or 9 if x=3, and 2 or 3 if x=4 or 5 n=an integer≧1 if y=7, 8 or 9, and an integer≧2 if y=2 or 3, said fiber having a tensile modulus between 30 million and 60 million, said resin requiring processing at temperatures between 300° F. and 500° F. and exhibiting a strain to failure ratio of less than about 2%, and said composite laminate being substantially microcrack free.
Claim 2
Dependent Claim
198 words
A composite laminate, comprising a plurality of plies of graphite fiber reinforced resin, having the graphite fibers aligned in substantially unidirectional orientation within each ply, and having the plies aligned in layers and laid up in the laminate according to the formula: (A.sub.x B.sub.y A.sub.x).sub.n wherein A and B denote the orientation of the fibers in successive layers as the angular displacement of the fiber direction relative to a reference direction of 0°, and x and y denote the number of plies comprising each of the successive layers, and n denotes the number of times the three-layer unit (A x B y A x ) is repeated in the laminate, and A=90°±10° B=0° x=2, 3, 4 or 5 y=7, 8 or 9 if x=2, and 2, 7, 8 or 9 if x=3, and 2 or 3 if x=4 or 5 n=an integer≧1 if y=7, 8 or 9, and an integer≧2 if y=2 or 3, said fiber having a tensile modulus between 30 million and 60 million, said resin requiring processing at temperatures between 300° F. and 500° F. and exhibiting a strain to failure ratio of less than about 2%, and said composite laminate being substantially microcrack free.
Claim 3
Dependent Claim
19 words
The composite laminate of claim 1 wherein A=90° B=0° x=4 y=2 n=an integer≧2 and the resin comprises bismaleimide resin.
Claim 4
Dependent Claim
19 words
The composite laminate of claim 1 wherein A=90° B=0° x=2 y=8 n=an integer≧1 and the resin comprises bismaleimide resin.
Claim 5
Independent Claim
229 words
A method of making a composite laminate, comprising (a) laying up a plurality of plies of graphite fiber reinforced resin, having the graphite fibers aligned in substantially unidirectional orientation within each ply, and having the plies aligned in layers and laid up in the laminate according to the formula: (A.sub.x B.sub.y A.sub.x).sub.n wherein A and B denote the orientation of the fibers in successive layers as the angular displacement of the fiber direction relative to a reference direction of 0°, and x and y denote the number of plies comprising each of the successive layers, and n denotes the number of times the three-layer unit (A x B y A x ) is repeated in the laminate, and A=90°±10° B=0° x=2, 3, 4 or 5 y=7, 8 or 9 if x=2, and 2, 7, 8 or 9 if x=3, and 2 or 3 if x=4 or 5 n=an integer≧1 if y=7, 8 or 9, and an integer≧2 if y=2 or 3, (b) heating the laminate to a temperature between 300° F. and 400° F. to cure the resin, (c) heating the laminate to a temperature between 350° F. and 500° F. to postcure the resin, said fiber having a tensile modulus between 30 million and 60 million, said resin exhibiting a bulk strain to failure ratio of less than about 2%, and said composite laminate being substantially microcrack free.
Claim 6
Independent Claim
229 words
A method of making a composite laminate, comprising (a) laying up a plurality of plies of graphite fiber reinforced resin, having the graphite fibers aligned in substantially unidirectional orientation within each ply, and having the plies aligned in layers and laid up in the laminate according to the formula: (A.sub.x B.sub.y A.sub.x).sub.n wherein A and B denote the orientation of the fibers in successive layers as the angular displacement of the fiber direction relative to a reference direction of 0°, and x and y denote the number of plies comprising each of the successive layers, and n denotes the number of times the three-layer unit (A x B y A x ) is repeated in the laminate, and A=90°±10° B=0° x=2, 3, 4 or 5 y=7, 8 or 9 if x=2, and 2, 7, 8 or 9 if x=3, and 2 or 3 if x=4 or 5 n=an integer≧1 if y=7, 8 or 9, and an integer≧2 if y=2 or 3, (b) heating the laminate to a temperature between 300° F. and 400° F. to cure the resin, (c) heating the laminate to a temperature between 350° F. and 500° F. to postcure the resin, said fiber having a tensile modulus between 30 million and 60 million, said resin exhibiting a bulk strain to failure ratio of less than about 2%, and said composite laminate being substantially microcrack free.
Claim 7
Dependent Claim
18 words
The method of claim 4 wherein A=90° B=0° x=4 y=2 n=an integer≧2 and the resin comprises bismaleimide resin.
Claim 8
Dependent Claim
18 words
The method of claim 4 wherein A=90° B=0° x=2 y=8 n=an integer≧1 and the resin comprises bismaleimide resin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |