GB2072579A - Stiffened panel of fibre reinforced plastics materials - Google Patents
Stiffened panel of fibre reinforced plastics materials Download PDFInfo
- Publication number
- GB2072579A GB2072579A GB8109541A GB8109541A GB2072579A GB 2072579 A GB2072579 A GB 2072579A GB 8109541 A GB8109541 A GB 8109541A GB 8109541 A GB8109541 A GB 8109541A GB 2072579 A GB2072579 A GB 2072579A
- Authority
- GB
- United Kingdom
- Prior art keywords
- base web
- fibres
- stiffened panel
- region
- strip
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000000463 material Substances 0.000 title claims abstract description 15
- 229920002430 Fibre-reinforced plastic Polymers 0.000 title claims abstract description 12
- 239000011151 fibre-reinforced plastic Substances 0.000 title claims abstract description 12
- 230000007704 transition Effects 0.000 claims description 8
- 230000003014 reinforcing effect Effects 0.000 claims description 7
- 230000003247 decreasing effect Effects 0.000 claims description 2
- 230000001419 dependent effect Effects 0.000 claims 1
- 239000002990 reinforced plastic Substances 0.000 abstract 1
- 239000003351 stiffener Substances 0.000 description 7
- 239000011347 resin Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000000835 fiber Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 3
- 238000005336 cracking Methods 0.000 description 3
- 238000006731 degradation reaction Methods 0.000 description 3
- 239000010410 layer Substances 0.000 description 2
- 102000004726 Connectin Human genes 0.000 description 1
- 108010002947 Connectin Proteins 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000003467 diminishing effect Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
- B32B3/10—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material
- B32B3/14—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a discontinuous layer, i.e. formed of separate pieces of material characterised by a face layer formed of separate pieces of material which are juxtaposed side-by-side
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
- B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
- B32B5/26—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer another layer next to it also being fibrous or filamentary
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C1/00—Fuselages; Constructional features common to fuselages, wings, stabilising surfaces or the like
- B64C1/06—Frames; Stringers; Longerons ; Fuselage sections
- B64C1/12—Construction or attachment of skin panels
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
- B32B2260/02—Composition of the impregnated, bonded or embedded layer
- B32B2260/021—Fibrous or filamentary layer
- B32B2260/023—Two or more layers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
- B32B2260/04—Impregnation, embedding, or binder material
- B32B2260/046—Synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B2309/00—Parameters for the laminating or treatment process; Apparatus details
- B32B2309/06—Angles
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Aviation & Aerospace Engineering (AREA)
- Reinforced Plastic Materials (AREA)
- Laminated Bodies (AREA)
Abstract
A stiffened panel comprises a base web 1 of reinforced plastics material and a plurality of strips 2 of a fibre reinforced plastics material. Each strip has two edge region 3 and 4, with an intermediate region 5 between. The strips 2 are arranged in generally side-by-side relationship upon the base web 1 with their intermediate regions 5 bonded to a first face of the base web 1. Adjacent edge regions 3, 4 are turned to upstand from the base web 1 and are bonded one to the other. <IMAGE>
Description
SPECIFICATION
Stiffened panel of fibre reinforced plastics materials
This invention relates to stiffened panels formed of fibre reinforced plastics materials.
The reinforcing fibres may be of carbon.
Conventional stiffened panels exist which comprise a discretely moulded skin and discretely moulded stringers of channel section which are subsequently bonded to the skin.
This form of stiffened panel suffers from the disadvantage that it is difficult to bed the stringers down on the skin sufficiently to give the consistent thin glue line necessary if the bonded joints are to be sufficiently strong. In addition, there is an exposed resin fillet where a portion of the stringer upstands from the base web. The exposed fillet may be prone to adhesive degradation. Moreover, the corner region between the portion of the stringer attached to the base web and that portion of the stringer upstanding from the base web may flex, thus causing cracking or degradation of the resin fillet.
It is an aim of this invention to provide a stiffened panel which overcomes at least some of the disadvantages of the above form of stiffened panel.
According to this invention, there is provided a stiffened panel which includes a base web of fibre-reinforced plastics material, and a plurality of strips of fibre reinforced plastics material, each strip having spaced edge regions with an intermediate region between, the strips being arranged in generally side-byside relationship upon the base web with their intermediate regions bonded to a first face of the base web and their edge regions upstanding from the base web, one edge region of one strip being bonded in a back-to-back relationship to an edge region of a further strip, and the other edge region of said one strip being bonded in a back-to-back relationship to an adjacent edge region of yet a further strip. It will be appreciated that in this form of stiffened panel any resin fillet formed at the base of the upstanding regions will be enclosed.Preferably a backing web of fibre reinforced plastics material is bonded to that second face of base web, remote from said first face.
Preferably the upstanding edge regions have upper portions turned over together to define a flange portion lying generally parallel to the base web.
The base web advantageously includes fibres set at substantially 0 , 90 , - 45" and + 45 . In this case, the upstanding edge regions may advantageously be generally aligned with those reinforcing fibres of the base web which are set at 0'. In addition, the strips may include fibres set at substantially 0" and 90 .
The strips may include fibres at substantially - 45" and + 45 , in addition to fibres at 0" and 90o, but the 0" and 90 fibres predominating, and the - 45" and + 45" fibres being positioned in each strip such that they lie on or adjacent the adjoining faces of adjacent strips.
The backing web, where provided, may include fibres set at substantially 0" and 90 .
The panel is conveniently provided with a connecting region, arranged to allow connectin to a further structural element, and a transition region leading to the connecting region, a progressively increasing portion of the upstanding edge portions in the transition region being turned over together to lie substantially parallel to the base web, the height of the upstanding edge regions proportionally decreasing, so that eventually the connecting region is provided wherein substantially the whole of the upstanding edge regions comprise turned over portions.
One embodiment of the invention is described with reference to the accompanying drawings, in which:
Figure 1 is a plan view of part of stiffened panel,
Figure 2 is a cross sectional view upon
Arrows ll-ll of Fig. 1,
Figure 3 is a plan view of both a transition region and a connecting region,
Figure 4 is a side view of Fig. 3, that is to say, a view of Arrow X,
Figure 5 is a cross sectional view upon
Arrows A-A of Fig. 3, and
Figure 6 is a cross sectional view upon
Arrows B-B of Fig. 3, and
Figure 7 is a cross sectional view upon
Arrows C-C of Fig. 3.
In Figs. 1 and 2, a stiffened panel has a base web 1 of a carbon fibre reinforced plastics material, the reinforcing fibres of which are set at 0 , 90 , - 45", and + 45 as illustrated in Fig. 1. The panel further has stiffeners formed on one face of the base web 1 by individual strips 2 of a carbon fibre reinforced plastics material, the reinforcing fibres of which are also set at 0 , 90 , - 45', and + 45 . The 0" and the 90 fibre orientations predominate.The - 45" and + 45 fibre orientations may be provided by layers of unidirectional fibred sheet and/or woven, plain weave, fabric.
Each strip has an edge region 3 and an edge region 4 with an intermediate region 5 between. The strips 2 are arranged in generally side-by-side relationship upon the base web 1, the strips having their lengths generally aligned with the 0" fibre settihgs. The intermediate regions 5 are bonded to the base web 1 whilst the edge regions 3 and 4 are turned through 90 to extend normally from the base web 1. In other words, they are upstanding from it. Since individual strips 2 lie generally side-by-side an edge region 3 of one strip will lie back-to-back with an edge region 4 of an adjacent strip and is bonded to it to form a double thickness stiffener. A tip portion of each edge region 3 and 4 is turnedover through about 90 to lie generally parallel with the base web 1.Each turned-over portion is referenced 6. For ease of reference the height of each stiffener is referenced Y whilst the width is referenced Z.
The - 45" and + 45' fibre orientation layers are positioned toward one surface of each strip 2, so that they lie as near as possible coincident with the longitudinal centre line of the upstanding double thickness stiffener.
A backing web 7 is bonded to that face of the base web 1 remote from that face to which the strips 2 are bonded. This web 7 has its reinforcing fibres set both at 0" and 90 . The 0" orientation predominates.
Referring now to Figs. 3 to 7, a connecting region denoted by Arrow D, and a transition region denoted by Arrow E are provided. The connecting region enables the panel to be structurally connected to other structural members, not shown, whilst the transition region blends the panel proper into the connecting region with little or no loss in strength.
In the transition region, each stiffener formed of items 3 and 4 is of progressively diminishing height Y, the excess material of regions 3 and 4 being incorporated in a proportionally increasing width Z. A comparison between Fig. 5 and Fig. 6 clearly illustrates this. This progressive change continues the length of Arrow E until, at Arrow D, the height Y is at a minimum and the width Z is at a maximum. In the region of Arrow D that material of one strip 2 forming the region 4 is locally severed from the remainder of its strip so that it can be readily turned back through 180 to lie as a single layer sandwiched between the region 3 of an adjacent strip 2 and that portion of said one strip 2 bonded to the base web 1.
As the width Z increases along the length of
Arrow E the upstanding edge regions 3 and 4 are arranged to diverge from a centre line referenced CL of the width Z so that at all stations along Arrow E, the width Z, that is to say, the turned-over portion 6, remains equally disposed about the centre line.
The illustrated arrangement provides certain advantages. These can be summarised as follows:
a. The attachment area between a stiffener (that is to say, 3, 4) and the sheet (1) to be stiffened is very large.
b. The stiffeners (3, 4) all contain an orientation of fibres in which the 0" and 90 reinforcing fibres predominate, thereby giving desired load bearing properties.
c. There are two opposing corners where the regions (3, 4) are bonded back-to-back.
This stiffens the upstanding portion and helps to prevent tilting of the regions (3, 4) with reference to the base web (1). Resin cracking is accordingly minimised.
d. A resin fillet formed between the back-toback regions (3, 4) and the base web (1) is found to be small and is well supported; it is accordingly resistant to cracking. Moreover, it is totally enclosed which will help chemical and physical damage degradation of the resin.
e. The panel is readily inspectable.
f. Tooling for manufacture is found to be simple and easy to construct.
g. To enable attachment to other structures a connection portion (D) can be provided in a straightforward manner.
Claims (9)
1. A stiffened panel which includes a base web of fibre-reinforced plastics material, and a plurality of strips of fibre reinforced plastics material, each strip having spaced edge regions with an intermediate region between, the strips being arranged in generally side-byside relationship upon the base web with their intermediate regions bonded to a first face of the base web and their edge regions upstanding from the base web, one edge region of one strip being bonded in a back-to-back relationship to an adjacent edge region of a further strip, and the other edge region of said one strip being bonded in a back-to-back relationship to an adjacent edge region of yet a further strip.
2. A stiffened panel according to claim 1, wherein a backing web of fibre reinforced plastics material is bonded to that second face of base web, remote from said first face.
3. A stiffened panel according to claim 1 or claim 2, wherein the upstanding edge regions have upper portions turned over together to define a flange portion lying generally parallel to the base web.
4. A stiffened panel according to any of the preceding claims wherein the base web includes fibres set at substantially 0 , 90 , -45' and +45'.
5. A stiffened panel according to claim 4, wherein the upstanding edge regions are sen- erally aligned with those reinforcing fibres of the base web which are set at 0'.
6. A stiffened panel according to claim 4 or claim 5, wherein the strips include fibres set at substantially 0" and 90 , fibres of a particular orientation in the intermediate region being aligned with correspondingly orientated fibres of the base web.
7. A stiffened panel according to claim 6, wherein the strips further include fibres at substantially - 45" and + 45 , the 0 and 90 fibres predominating, and the - 45" and
+ 45 fibres being positioned in each strip such that they lie on or adjacent the adjoining faces of adjacent strips.
8. A stiffened panel, according to claim 2 or any claim dependent on claim 2, wherein the backing web includes fibres set at substantially 0" and 90 being aligned with corresponding fibres in the base web.
9. A stiffened panel according to any of the preceding claims, wherein the panel is provided with a connecting region, arranged to allow connection to a further structural element, and a transition region leading to the connecting region, a progressively increasing portion of the upstanding edge regions in the transition region being turned over together to lie substantially parallel to the base web, the height of the upstanding edge regions proportinally decreasing, so that eventually the connecting region is provided wherein substantially the whole of the upstanding edge regions comprise turned over portions.
1 0. A stiffened panel substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8010941 | 1980-04-01 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2072579A true GB2072579A (en) | 1981-10-07 |
| GB2072579B GB2072579B (en) | 1984-06-06 |
Family
ID=10512540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8109541A Expired GB2072579B (en) | 1980-04-01 | 1981-03-26 | Stiffened panel of fibre reinforced plastics materials |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2072579B (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0217315A2 (en) * | 1985-09-30 | 1987-04-08 | The Boeing Company | Wing box cover panel and method of making same |
| EP0758607A3 (en) * | 1995-08-11 | 1998-04-01 | Deutsches Zentrum für Luft- und Raumfahrt e.V. | Shear-proof aircraft wing box formed from fibre reinforced material |
| WO2000009321A1 (en) * | 1998-08-15 | 2000-02-24 | Bae Systems Plc | Composite material construction |
| EP1566334A1 (en) * | 2004-02-20 | 2005-08-24 | Airbus France | Stiffener end with staggered slopes and panel with such stiffener end |
| US7546864B2 (en) | 2000-09-07 | 2009-06-16 | Airbus Uk Limited | Stiffening means for structural components, method of manufacturing and apparatus therefor |
| EP1942052B2 (en) † | 2006-12-13 | 2016-11-02 | The Boeing Company | Rib support for wing panels |
| US10023293B2 (en) | 2010-09-28 | 2018-07-17 | Airbus Operations Limited | Stiffener run-out |
-
1981
- 1981-03-26 GB GB8109541A patent/GB2072579B/en not_active Expired
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0217315A2 (en) * | 1985-09-30 | 1987-04-08 | The Boeing Company | Wing box cover panel and method of making same |
| JPS62168789A (en) * | 1985-09-30 | 1987-07-25 | ザ ボーイング カンパニー | Wing-box cover panel and manufacture thereof |
| EP0217315A3 (en) * | 1985-09-30 | 1988-01-07 | The Boeing Company | Wing box cover panel and method of making same |
| EP0758607A3 (en) * | 1995-08-11 | 1998-04-01 | Deutsches Zentrum für Luft- und Raumfahrt e.V. | Shear-proof aircraft wing box formed from fibre reinforced material |
| WO2000009321A1 (en) * | 1998-08-15 | 2000-02-24 | Bae Systems Plc | Composite material construction |
| US6582792B1 (en) | 1998-08-15 | 2003-06-24 | Bae Systems Plc | Composite material construction |
| US7546864B2 (en) | 2000-09-07 | 2009-06-16 | Airbus Uk Limited | Stiffening means for structural components, method of manufacturing and apparatus therefor |
| EP1566334A1 (en) * | 2004-02-20 | 2005-08-24 | Airbus France | Stiffener end with staggered slopes and panel with such stiffener end |
| FR2866626A1 (en) * | 2004-02-20 | 2005-08-26 | Airbus France | OFFSET OF STIFF SLITTED SLOPES AND PANEL PROVIDED WITH SUCH A STOP |
| US7682682B2 (en) | 2004-02-20 | 2010-03-23 | Airbus France | Stiffener stop with staggered slopes and panel fitted with such a stop |
| EP1942052B2 (en) † | 2006-12-13 | 2016-11-02 | The Boeing Company | Rib support for wing panels |
| US10023293B2 (en) | 2010-09-28 | 2018-07-17 | Airbus Operations Limited | Stiffener run-out |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2072579B (en) | 1984-06-06 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |