Joint for composite wings

A wing joint including a T-chord and a splice plate for connecting an inboard wing panel assembly and an outboard wing panel assembly. The wing panel assemblies include a stringer co-bonded or co-cured with a wing skin. The webbing and cap of the stringer may be trimmed to expose a noodle and base flange. The noodle and base flange interface with the bottom of the T-chord and the wing skin interfaces with the splice plate. The exposed noodle may be non-flush with the base flange of the trimmed stringer. The bottom of the T-chord may include a groove to accommodate a non-flush noodle so that a gap does not exist between the T-chord and the base flange. Alternatively, shims may be used to compensate for a non-flush noodle or the base flange and web may include sacrificial plies permitting the base flange and web to be trimmed flush with the noodle.

BACKGROUND

1. Field of the Disclosure

The configurations described herein relate to a joint for composite wings. The joint may be for a lower side-of-body joint of an aircraft.

2. Description of the Related Art

Bolted side-of-body joints may be used to connect wings to the fuselage of an aircraft. One design of a side-of-body joint200presently used to connect a wing to a fuselage is shown inFIG. 12. The joint200includes a double plus chord210that includes a vertical portion211, an upper inboard portion212, a lower inboard portion213, an upper outboard portion214, and a lower outboard portion215. An inboard wing panel assembly220is connected to the inboard side of the double plus chord210and an outboard wing panel assembly230is connected to the outboard side of the double plus chord210.

The inboard wing panel assembly220includes a stringer260connected to an inboard wing skin240and the outboard wing panel assembly230includes a stringer260connected to an outboard wing skin250. The stringer260includes a base flange261on the bottom of the stringer260and a cap263located on the top with a web262connecting the cap263to the base flange261. The base flange261of the stringer260is connected to the inboard wing skin240. The base flange261may be bonded to the inboard wing skin240.

The cap263is connected to the upper inboard portion212of the double plus chord210by a plurality of fasteners281. A portion of the web262and base flange261of the stringer260is cut so that base flange261of the stringer260does not overlap the lower inboard portion213of the double plus chord210. A radius filler plate291is positioned above the base flange261. Fasteners290connect the radius filler plate291to the base flange261and the inboard wing skin240, which clamp the inboard wing skin240and base flange261to form a crack arrestment mechanism. Only the inboard wing skin240of the inboard wing panel assembly220is positioned below the lower inboard portion213of the double plus chord210. The inboard wing skin240is positioned between the lower inboard portion213of the double plus chord210and a splice plate270. Fasteners280connect the splice plate270to the lower inboard portion213of the double plus chord210securing the inboard wing skin240to the joint200.

The outboard wing panel assembly230is constructed the same way as the inboard wing panel assembly220. Fasteners281are used to connect the cap263of the stringer260to the upper outboard portion214of the double plus chord210. Fasteners280connect the outboard wing skin250to the splice plate270and the lower outboard portion215of the double plus chord210. The connection of one portion of a wing panel assembly to a first portion of a joint, and the connection of a second portion of a wing panel assembly to a second portion of the joint may result in differing forces to be applied to the different portions of the assembly.

SUMMARY

It may be beneficial to provide a joint that secures both portions of a wing panel assembly with a clamping configuration having a single interface.

One configuration is a wing joint comprising a T-chord, a splice plate, an inboard wing panel assembly, and an outboard wing panel assembly. The T-chord includes an inboard portion, an outboard portion, and a vertical portion. The splice plate has an inboard portion and an outboard portion. The wing joint includes at least one inboard stringer connected, such as being bonded, to the inboard wing skin to form an inboard wing panel assembly and at least one outboard stringer connected, such as being bonded, to the outboard wing skin to form an outboard wing panel assembly. A portion of the inboard wing panel assembly is positioned between the inboard portion of the T-chord and the inboard portion of the splice plate. A portion of the outboard wing panel assembly is positioned between the outboard portion of the T-chord and the outboard portion of the splice plate. A first plurality of fasteners connect the inboard portion of the T-chord with the inboard portion of the splice plate to secure the inboard wing panel assembly to the T-chord and the splice plate. A second plurality of fasteners connect the outboard portion of the T-chord with the outboard portion of the splice plate to secure the outboard wing panel assembly to the T-chord and the splice plate.

The outboard stringer and inboard stringer of the wing joint may each include a base flange, at least one web, and at least one noodle. The outboard stringer and inboard stringer may be blade stringers. The outboard stringer and inboard stringer may be I stringers. The I stringers may include a cap. The inboard stringer and outboard stringer may each be trimmed to expose at least one noodle. The inboard wing panel assembly may comprise a portion of an inboard wing skin, a portion of a base flange of an inboard stringer, and a portion of at least one exposed noodle. The outboard wing panel assembly may comprise a portion of an outboard wing skin, a portion of a base flange of an outboard stringer, and a portion of at least one exposed noodle.

The T-chord of the joint may include a first groove in the inboard portion to accommodate at least one exposed noodle of an inboard stringer and a second groove in the outboard portion to accommodate at least one exposed noodle of an outboard stringer. The joint may include a first shim positioned between the base flange of an inboard stringer and the inboard portion of the T-chord and a second shim positioned between the base flange of the outboard stringer and the outboard portion of the T-chord. The first and second shims may be positioned adjacent to at least one exposed noodle. The joint may be a lower side-of-body joint for a composite wing assembly.

The inboard portion of the T-chord may include at least one cutout and the outboard portion of the T-chord may also include at least one cutout. A portion of the web of the inboard stringer may extend into the cutout on the inboard portion of the T-chord and a portion of the web of the outboard stringer may extend into the cutout on the outboard portion of the T-chord. The inboard and outboard portions of the T-chord may include at least three longitudinal rows of fasteners securing the wing panel assemblies to the T-chord and the splice plate. The cutouts on the inboard and outboard portions of the T-chord may extend between fasteners in at least one row of the fasteners. The cutouts on the inboard and outboard portions of the T-chord may extend between fasteners in at least two rows of the fasteners. The T-chord and splice plate of the joint may be comprised of titanium or aluminum.

One configuration is a method of forming a wing joint. The method comprises forming an inboard wing panel assembly and forming an outboard wing panel assembly. The inboard wing panel assembly comprises at least one inboard stringer connected to an inboard wing skin, the stringer including a base flange, at least one web, and at least one noodle. The outboard wing panel assembly comprises at least one outboard stringer connected to an outboard wing skin, the stringer including a base flange, at least one web, and at least one noodle. The method includes trimming the web of the inboard stringer to expose at least one noodle and trimming the web of the outboard stringer to expose at least one noodle. The method includes positioning a portion of the inboard wing panel assembly between an inboard portion of a T-chord and an inboard portion of a splice plate and securing the inboard wing panel assembly to the T-chord and splice plate with a plurality of fasteners. The portion of the inboard wing panel assembly including a portion of the inboard wing skin, a portion of the base flange of the inboard stringer, and at least one exposed noodle. The method includes positioning a portion of the outboard wing panel assembly between an outboard portion of a T-chord and an outboard portion of a splice plate and securing the outboard wing panel assembly to the T-chord and splice plate with a plurality of fasteners. The portion of the outboard wing panel assembly including a portion of the outboard wing skin, a portion of the base flange of the outboard stringer, and at least one exposed noodle.

The method may include providing a groove in the inboard portion of the T-chord to accommodate at least one exposed noodle of the inboard stringer and providing a groove in the outboard portion of the T-chord to accommodate at least one exposed noodle of the outboard stringer. The method may include providing at least a first shim positioned between the inboard wing panel assembly and the inboard portion of the T-chord and providing at least a second shim positioned between the outboard wing panel assembly and the outboard portion of the T-chord. The shims may be positioned adjacent to at least one exposed noodle.

The stringers or the method may be composite materials comprised of a plurality of plies. The method may include adding additional sacrificial plies to the stringers prior to forming the wing panel assemblies, the sacrificial plies permitting the removal of at least a portion of the sacrificial plies to provide that an exposed noodle is flush without reducing the load bearing capability of the wing panel assemblies. The forming an inboard wing panel assembly may further comprise co-curing the inboard wing skin and the inboard stringer and forming an outboard wing panel assembly may further comprise co-curing the outboard wing skin and the outboard stringer. The forming an inboard wing panel assembly may further comprise co-bonding the inboard wing skin and the inboard stringer and forming an outboard wing panel assembly may further comprise co-bonding the outboard wing skin and the outboard stringer.

One configuration is a wing joint that comprises a first clamp plate, a second clamp plate, and a wing panel assembly. The wing panel assembly is comprised of a stringer bonded to a wing skin. A portion of the wing panel assembly is secured between the first clamp plate and the second clamp plate. The stringer of the wing panel assembly has been trimmed to expose a noodle, which is part of the portion of the wing panel assembly secured between the first clamp plate and the second clamp plate.

DETAILED DESCRIPTION

FIG. 1shows a configuration of a wing joint1. The wing joint1includes a first clamp plate10and a second clamp plate15used together to secure an inboard wing panel assembly20and an outboard wing panel assembly30. The first clamp plate10may be a T-chord and the second clamp plate may be a splice plate. Hereinafter, the first clamp plate will be referred to as a T-chord10and the second clamp plate will be referred to as a splice plate15. The T-chord10includes a vertical portion11, an inboard portion12, and an outboard portion13. The splice plate15includes an inboard portion16and an outboard portion17. The T-chord10and splice plate15are used to connect together an inboard wing panel assembly20and an outboard wing panel assembly30.

The inboard wing panel assembly20is comprised of an inboard wing skin40and a stringer60. The inboard wing skin40and the stringer60may both be comprised of a composite material, which may be comprised of multiple layers of a material bonded and/or cured together. The material may be comprised of various materials used in the formation of composite materials. One example of such material is carbon fiber reinforced plastic. Likewise, the outboard wing panel assembly30is comprised of an outboard wing skin50and a stringer60. As discussed above, the outboard wing skin50and the stringer60may also be co-bonded or co-cured. The stringer60used may be various stringers used to strengthen composite parts, such as an I stringer or a blade stringer.

The stringer60is bonded to the wing skin40,50to form a wing panel assembly20,30. The stringer60and wing skin40,50may be co-cured so as to form a bond between the two components. After the wing panel assemblies20,30are formed, the wing panel assemblies20, may then be connected together with T-chord10and splice plate15to form a wing joint1. The stringer60may include a base flange61and a web62. If the stringer60is an I stringer, as shown inFIG. 8, then the stringer60may include a cap63. The cap63and web62of the stringer60may be trimmed so that only the base flange61of the stringer60runs out into the wing joint1. The cap63and web62may be trimmed to expose a noodle64or a plurality of noodles as discussed below.

An end portion of the inboard wing panel assembly20may be positioned between the inboard portion12of the T-chord10and the inboard portion16of the splice plate15. As discussed above, the web62and cap63may be been trimmed so that only the base flange61of the stringer60, which is bonded to the inboard wing skin40, is positioned between the T-chord10and the splice plate15. As discussed below, the stringer60may also include an exposed noodle(s)64that is also positioned between the T-chord10and the splice plate15. A plurality of fasteners80connect the inboard portion12of the T-chord10to the inboard portion16of the splice plate15, securing the inboard wing panel assembly20to the wing joint1. Likewise, the outboard wing panel assembly30is connected to the outboard portion13of the T-chord10and the outboard portion17of the splice plate15.

FIG. 2shows a partial cross-section of a wing panel assembly20that includes a stringer60bonded to a wing skin40. The web62and cap63have been trimmed to expose a noodle64on the base flange61of the stringer60. Noodles64are typically unidirectional fibers that are used to fill a junction between portions of a stringer60as shown inFIG. 8. For example, an I stringer may be comprised of two “c” shaped brackets connected together back to back. A void may exist at both the top and bottom junctions where the back of the brackets meet. A noodle64, which may be a unidirectional fiber, may be used to fill the void. The noodle64may be comprised of various materials, such as unidirectional carbon fiber reinforced plastic, laminated carbon fiber reinforced plastic, or glass fiber reinforced plastic. As shown inFIG. 2, the noodle64may not be flush with the base flange61. If the noodle64is not flush with the base flange61, the T-chord10or stringer60may be modified to accommodate the non-flush noodle64, as discussed below.

FIG. 3is a schematic showing the potential forces that may be applied to the wing joint1. As both the inboard wing skin40and base flange61are secured to the T-chord10and the splice plate15at the same interface, the same tension force is applied to both components equally as shown by arrow85. Further, the tension forces (arrows90) on both the T-chord10and splice plate15are substantially equal and in the same direction, because the two components provide a single interface for capturing the wing panel assembly20in comparison to the multiple interfaces of the double plus chord210shown inFIG. 12.

FIG. 4shows a portion of a stringer60that may be connected to the wing joint1of the present disclosure. The stringer60includes a base flange61and web62trimmed to expose a noodle64. The stringer60may include a web and cap run out65where the trimmed web62interfaces with the exposed noodle64. As discussed above, the noodle64may be comprised of unidirectional fiber and may fill a void between two interfaces in the stringer60.

FIG. 5AandFIG. 5Bshow a configuration of T-chord10that may be used in the wing joint1. The T-chord10may include a scalloped or cutout feature14that permits the web62of the stringer60, such as the blade of a blade stringer, to extend between one or more rows of fasteners80that connect the T-chord10to a spice plate15. The T-chord10may include a plurality of rows of fasteners80. For example, the T-chord10may include a first row of fasteners81, a second row of fasteners82, and a third row of fasteners83. The cutout feature14may protrude so it crosses the first and second rows of fasteners81,82as shown inFIG. 5AandFIG. 5B. The T-chord10may include a plurality of cutout features14. The use of the cutout feature14of the T-chord10may permit the stringer60to be more robust by permitting a longer length of web62along the stringer60. The number and orientation of the cutout features14is for illustrative purposes only. The configuration, depth, and location of the cutout features14, as well as the number of rows and configuration of fasteners, may be varied as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure. For example, even the individual length of the cutout features14may be varied within a single T-chord10.

FIG. 6shows a partial cross-section of a configuration of T-chord10that includes at least one groove18on the bottom side of the inboard portion12of the T-chord10. The groove18may be adapted to accommodate a non-flush noodle64present on the wing panel assemblies20,30. The insertion of the non-flush noodle64into the groove18may enable the interface between the T-chord10and wing panel assembly20to be flush. The T-chord10may include a plurality of grooves18in the bottom of both the inboard12and outboard13portions to accommodate a plurality of exposed noodles64.

FIG. 7shows a configuration of a trimmed stringer60that includes shims67to accommodate for non-flush noodles64. The shim(s)67are located adjacent to the non-flush noodle64between the base flange61and the T-chord10. The shims67fill the gaps between the wing panel assembly20,30and the T-chord10due to the noodle64being non-flush. The shims67are shown for illustrative purposes only as the shape, number, and configuration of the shims67may be varied, as would be appreciated by one of ordinary skill in the art having the benefit of this disclosure.

FIG. 8shows a cross-section of an I stringer60bonded to a wing skin40. The I stringer60includes a base flange61, a web62, and a cap63. For co-bonded wing panels, the base flange61may include a base flange charge66, which is not required for co-cured wing panels. The cap63may include a cap charge68for both co-bonded and co-cured wing panels. As shown, noodles64fill the gap between the web62and the cap63as well as the gap between the web62and the base flange61. As discussed above, the cap63and web62may be trimmed on one end of the stringer60to expose the noodle64. The exposed noodle64and base flange61may then interface with the bottom of the T-chord10when the wing panel assembly20, the stringer60bonded to the wing skin40, is secured to the T-chord10and the splice plate15, as discussed above.

FIG. 9shows a cross-section of a blade stringer60that includes additional plies or layers, referred to herein as sacrificial plies69, that permit the removal of material from the stringer60while maintaining the desired structural integrity of the stringer60. As discussed above, the web62of the stringer60is trimmed to expose the noodle64and provide an interface between the stringer60and the T-chord10. Upon exposing the noodle64, the noodle64may not be flush with the base flange61. To accommodate for a potential non-flush noodle64, sacrificial plies69are added to the web62and base flange61of the stringer60. The sacrificial plies permit the web62and base flange61to be trimmed down to a level70, which is flush with the exposed noodle64while retaining a thickness of material of the stringer60that maintains its intended structural integrity.

Referring more particularly to the drawings, configurations of the disclosure may be described in the context of an aircraft manufacturing and service method100as shown inFIG. 10and an aircraft102as shown inFIG. 11. During pre-production, exemplary method100may include specification and design104of the aircraft102and material procurement106. During production, component and subassembly manufacturing108and system integration110of the aircraft102takes place. Thereafter, the aircraft102may go through certification and delivery112in order to be placed in service114. While in service114by a customer, the aircraft102is scheduled for routine maintenance and service116(which may also include modification, reconfiguration, refurbishment, and so on).

As shown inFIG. 11, the aircraft102produced by exemplary method100may include an airframe118with a plurality of systems120and an interior122. Examples of high-level systems120include one or more of a propulsion system124, an electrical system126, a hydraulic system128, and an environmental system130. Any number of other systems may be included. Although an aerospace example is shown, the principles of the disclosure may be applied to other industries, such as the automotive industry.

Apparatus and method embodied herein may be employed during any one or more of the stages of the aircraft manufacturing and service method100. For example, components or subassemblies corresponding to production process108may be fabricated or manufactured in a manner similar to components or subassemblies produced while the aircraft102is in service114. Also, one or more apparatus configurations, method configurations, or a combination thereof may be utilized during the production processes108and110, for example, by expediting assembly of or reducing the cost of an aircraft102. Similarly, one or more of apparatus configurations, method configurations, or a combination thereof may be utilized while the aircraft102is in service114, for example and without limitation, to maintenance and service116.

Although this disclosure has been described in terms of certain preferred configurations, other configurations that are apparent to those of ordinary skill in the art, including configurations that do not provide all of the features and advantages set forth herein, are also within the scope of this disclosure. Accordingly, the scope of the present disclosure is defined only by reference to the appended claims and equivalents thereof.

TABLE OF REFERENCE NUMERALS FOR FIGS. 1-121wing joint10T-chord11vertical portion of T-chord12inboard portion of T-chord13outboard portion of T-chord14cutout feature in T-chord15splice plate16inboard portion of splice plate17outboard portion of splice plate18grooves in T-chord20inboard wing panel assembly30outboard wing panel assembly40inboard wing skin50outboard wing skin60stringer61base flange62web63cap64noodle65cap and web run out66base flange charge67shim68cap charge69sacrificial plies70trimmed level80fastener81first row of fasteners82second row of fasteners83third row of fasteners85tension force on wing panel assembly90tension force on T-chord and splice plate200prior art wing joint210double plus chord211vertical portion of double plus chord212upper inboard portion of double plus chord213lower inboard portion of double plus chord214upper outboard portion of double plus chord215lower outboard portion of double plus chord220inboard wing panel assembly230outboard wing panel assembly240inboard wing skin250outboard wing skin260stringer261stringer base flange262stringer web263stringer cap270splice plate280fastener281fastener282fastener291radius filler