DE102005015337B4 - Box girder of an aerodynamic surface structure - Google Patents

Abstract

Box girder of an aerodynamic surface structure, which is formed from two supporting aerodynamic panels (1, 2) with half-rib components (14, 15) arranged transversely to the span and first and second spars (4, 5) running in the span direction and by connecting elements (17, 18, 27 , 28, 29; 39, 40), characterized in that the half-rib components (14) of the one aerodynamic panel (1) and the corresponding half-rib components (15) of the second aerodynamic panel (2) on a near the first spar (4th ) arranged first position immovably connected to one another and held at a rigid distance from each other at a second position spaced apart from them in terms of their longitudinal direction and close to the second spar (5).

Description

The invention relates to a box girder of an aerodynamic surface structure according to the preamble of claim 1.

Conventional box girders of aerodynamic surface structures, such. As of wings or tail, represent a total of stringerversteiften hides (panels), spars and ribs, which are interconnected by bolts or rivets. Such constructions make z. B. use of center boxes made of CFRP materials, as in the aircraft B-777 and A-310, described for example at Heißler H., "Reinforced plastics in aerospace engineering", Verlag W. Kohlhammer, Stuttgart, Berlin, Cologne , Mainz, 1986; Fawcett A. Trostle J., Ward S. "777 Empennage Certification Approach", 11-th International Conference on Composite Materials (ICCM-11), Australia, July 14-18, 1997; Flight Review, September 1999; Bergmann H. W., "Construction principles for fiber composite components" Springer-Verlag, Berlin, Heidelberg, 1992. The assembly of these center boxes takes place in a long assembly line with complex fixation of the numerous ribs on a sliding unit and with subsequent riveting with stringerversteiften shells and often using additional connecting components. The production of stringerversteiften panels is also complicated by the design of stringers (integral construction) or by a special production of stringers and subsequent positioning and Polimerisation (adhesion) to the skins.

In aircraft IL-28, a two-bar wingbox beam is provided, the material of which consists of metal alloys and which comprises an upper and a lower shell, each shell having a half-rib and half-spar structure with stringers described, for example, in Schulshenko MN "Construction of Aircraft", Military Publisher, Berlin, 1976; Glagolev AN, Goldinov MJ, Grigorenko SM "Construction of Aircraft" (in Russian), Maschinostroenie, Moscow, 1975 and Eden P., Mönk S. "Modern military aircraft", Bassermann Verlag, 2003. The two prefabricated shells (panels) are in the tendon plane coupled by two Halbholmeckprofile. The separation point in this case has only two rows of bolts in the stalk areas which extend in the spanwise direction. Such a construction and coupling construction significantly facilitates the assembly and thus reduces costs. This construction also offers the possibility to make both shells independently of each other and to distribute the work. On the other hand, the said construction is not a so-called "tolerance-free" design concept, because the accuracy of the aerodynamic contour is ultimately achieved by intermediate layers provided between the two shells belonging Halbholmeckprofilen and extend along the entire span of the box girder. This means extra customization and additional manufacturing costs. In addition, each prefabricated shell has numerous rivets between half-ribs, half-beams, skins and stringers, which is also time-consuming in the implementation of the assembly of each shell and contributes significantly to the manufacturing cost.

The proportion of components made of fiber composite materials is steadily increasing in aircraft construction, see Heißler H. "Reinforced plastics in the aerospace industry" a. a. O. and Niu M.C. Y. "Composite Airframe Structures", Second Published, Conmilit Press Ltd, Honkong, 1996.

Today's load-bearing fiber composite components mostly consist of CFRP materials (carbon fiber reinforced plastic). The use of these structural materials in aircraft construction provides significant weight reduction, but at a higher cost compared to the use of conventional metal alloys (eg, aluminum alloys). The higher input costs of fiber composites are to be justified on the one hand by higher CFRP material costs and on the other hand by higher production costs, cf. Bieling U. "Fiber-Reinforced Plastics in Civil Aviation", Innovative Vehicle Construction, Conference May 21, 2001 in Salzgitter, and Flemming N., Ziegmann G., Roth S. "Composite Structures: Semi-Finished Products and Construction Methods", Springer-Verlag, Berlin, Heidelberg 1996. The prices of CFRP materials, both the prices of their components (carbon fiber and resin systems) and their semi-finished products (eg prepregs), are still high today despite favorable developments in recent years.

From the US 2 403 569 A is an aerodynamic surface made of metal, such as a wing, a rudder or a flap, supported by a box girder formed by two aerodynamic panels with transversely spanwise half-rib members and spanwise beams and assembled by respective connecting elements , To produce the known surface structure, first respective half shells are formed, each comprising a planking, various stiffening and rib elements and rail elements close to the wing leading edge and the wing trailing edge. These half-shells are then joined together to form the final assembly. When assembling the half-shells, the elements of bars and ribs provided on each half-shell are connected to one another by spot welding. The transversely to the spanwise direction extending half ribs are connected to each other over their entire length extending from one spar to the other spar length. The nose region of the aerodynamic surface is formed by upper and lower half ribs, which extend forwards from the front spar and which overlap at their front ends and are welded together there. Next is from the US 2 558 819 A a wing of an aircraft and a method for producing such a known, with which the goal of a rational production should be achieved. The wing is formed by each with transverse to the spanwise extending half ribs stiffened skins comprehensive half-shells, which are connected at their front end by a spar and at its rear end by the skins directly to each other. To produce the wing first seen in the rib profile tapering towards each other upper and lower panels are connected together and then brought together the upper and lower shell and the half-ribs joined together by rivets. At the leading edge, the wing is then completed by a spar and a nose assembly. The nose assembly is formed by bending together a continuous plank which is stiffened by upper and lower half ribs, which are then also joined together. Then it is out of the DE 736 964 A known to manufacture for aircraft, in particular for aircraft wings, provided components with ribs by carving out the ribs from a flat or slightly curved metal planking, bent inwards and connected to an opposite planking of the component. The US 2 421 960 A describes the articulation of a control surface of an aircraft, which is realized by a control fork From the GB 635 823A Airfoils are known which have skins made of fiber-reinforced sandwich structures.

The object of the invention is to provide a box girder aerodynamic surface structure, which is to construct and assemble with reduced effort. In particular, such a box girder to be created, which is suitable for a structure of fiber composites.

This object is achieved by a box girder having the features of claim 1.

Advantageous developments and embodiments of the box girder according to the invention are specified in the subclaims.

The invention provides a box girder of an aerodynamic surface structure, which is formed from two load-bearing aerodynamic panels with transversely to the spanwise direction arranged semi-rib members and spanwise extending first and second spars and assembled by fasteners. According to the invention, it is provided that the half-rib members of the one aerodynamic panel and the corresponding half-rib members of the second aerodynamic panel are immovably connected to each other at a first location near the first spar and spaced apart from the second spar in a longitudinal direction thereof spaced apart from the second spar are held rigidly spaced from each other.

According to one embodiment of the invention, it is provided that the half-rib members are directly connected to each other at the first location.

According to another preferred embodiment of the invention, it is provided that the half-rib members are connected to each other at the first location via an intermediate component.

According to one embodiment of the invention, it is provided that the intermediate component in the rib plane is wedge-shaped.

According to one embodiment of the invention, it is provided that the first connection point lies with respect to the rib longitudinal direction in the region between the front and the rear spar.

According to another embodiment of the invention, it is provided that the first connection point with respect to the rib longitudinal direction is outside the region between the front and the rear spar.

According to an advantageous embodiment of the invention, it is provided that the half-ribs have a double-T-profile with straps, between which the connection of the first connection point is formed.

According to an advantageous embodiment of the invention, it is provided that the connection is formed at the first connection point by bolt connection.

According to another embodiment of the invention, it is provided that the connection is articulated at the first connection point.

In this case, the connection can be made at the first connection point by a hinge.

The connection at the second connection point can be made via a spar and / or the supporting panels.

Preferably, the connection is made at the second connection point by bolt connection.

According to an advantageous embodiment of the invention, it is provided that the spar at the second connection point is a spar with a one-piece profile, in particular with a C-profile.

According to another advantageous embodiment of the invention, it is provided that the spar at the second connection point contains a tolerance corner profile to compensate for distance tolerances between the first and second panels.

According to an advantageous embodiment of the invention, it is provided that the half-ribs continue at the second connection point in the form of half-ribbons beyond the spar.

Preferably, in this case, the connection between the half-belt and the rudder fork belts is performed by bolt connection.

According to an advantageous embodiment of the invention, it is provided that the second connection point is coupled to a coupling element for a flap or a rudder, in particular with a rudder fork.

According to an advantageous embodiment of the invention, it is provided that the articulation element is connected via first bolts to the half-ribbons and via second bolts to the half-ribbons and the panels.

According to an advantageous embodiment of the invention, it is provided that the load-bearing panels are designed in Stringerversteifungsbauweise.

According to a particularly advantageous embodiment of the invention, it is provided that the supporting panels are designed in sandwich construction.

According to an advantageous embodiment of the invention, it is provided that the core of the sandwich structure is a foam.

According to a particularly advantageous embodiment of the invention, it is provided that the inner skin of the sandwich panels as a flat surface ( 9 ) is trained.

In this case, provision may in particular be made for the half-ribs to have a constant cross-section over at least a substantial part of their length.

The ribs may form multiple groups, with the ribs of a group having equal rib heights and cross-sections.

The ribs can advantageously be manufactured by pultrusion method.

According to an advantageous embodiment of the invention, it is provided that the sandwich panel has a monolithic reinforcement in the front region.

According to another advantageous embodiment of the invention, it is provided that the sandwich panel has a monolithic reinforcement in the rear region.

Preferably, the sandwich panels are connected to the monolithic reinforcements by means of bolt connections to the respective spar.

According to an advantageous embodiment of the invention, it is provided that the panel at the end closer to the first connection point has a flanging for a coupling to the strut which is closer to the first connection point.

Preferably, the coupling of the flanging on the spar is carried out by bolt connection.

According to one embodiment of the invention, it is provided that the first connection point lies within the spar.

According to another embodiment of the invention, it is provided that the first connection point is outside the beam.

According to an advantageous embodiment of the invention, it is provided that the first connection point is arranged near the front spar and the second connection point near the rear spar of the aerodynamic surface structure.

Preferably, the half-rib components and / or the intermediate component are able to compensate for tolerances in the direction transverse to the rib plane.

According to one embodiment of the invention, the box girder is designed in metallic construction.

According to a particularly advantageous embodiment of the invention, the box girder is constructed by fiber composite components.

According to an advantageous embodiment of the invention, the fiber composite components of the box girder are manufactured in wet technology.

According to another advantageous embodiment of the invention, the fiber composite components of the box girder are manufactured in prepreg technology.

According to an advantageous embodiment of the invention, the ribs are glued to the panels.

According to another advantageous embodiment of the invention, the ribs are connected to the panels by co-polymerization.

In the following embodiments of the box girder invention will be explained with reference to the drawing.

It shows:

1 a simplified perspective exploded view of a box girder according to the invention of an aerodynamic surface structure;

2 a cross-sectional view of in 1 shown box girder according to the first embodiment of the invention;

3 an enlarged partial sectional view of the in 2 illustrated box girder along the line AA;

4 an enlarged partial sectional view of the in 2 illustrated box girder along the line BB;

5 another sectional view of the in 2 illustrated box girder according to the first embodiment of the invention with a schematized replacement representation of a force profile in the box girder representative truss; and

6 a cross-sectional view of a box girder of an aerodynamic surface structure according to a second embodiment of the invention.

In the 1 shown exploded view of a box girder an aerodynamic surface structure shows two load-bearing aerodynamic panels 1 . 2 and spanwise front and rear spars 4 . 5 , The panels 1 . 2 are supported by half ribs, of which the half ribs 3 of the second panel 2 are shown visible.

In the 2 shown cross-sectional view of the box girder according to a first embodiment of the invention shows side panels 1 . 2 made in sandwich construction with an outer skin 6 and an inner skin 7 and a foam core provided therebetween 8th are formed. The respective inner surface 9 the panels 1 . 2 is formed in the form of a plane.

The two panels 1 . 2 are of linearly extending half ribs 14 . 15 worn, which have a constant cross-section over the substantial part of their length. Such ribs can be easily prepared in series, for. B. by pultrusion technique and then on the panels 1 . 2 either glued or copolymerized in the panel production.

In the front area are the panels 1 . 2 through a front spar 4 interconnected, in the rear area are the panels 1 . 2 through a rear spar 5 connected with each other. Every panel 1 . 2 has a monolithic reinforcement in the front area 10 , which for receiving a possible sudden stress from the nose side 11 by z. B. a bird strike may occur, for protection and force introduction into the sandwich structure. On the other hand serves the monolithic area 10 also as a structural mechanical reinforcement for absorbing the bending stress of the entire box girder by aerodynamic forces. Every panel 1 . 2 can also have a monolithic reinforcement in the back area 12 have, which serves to absorb and distribute forces in this area, for example, actuators of rudders or flaps, as well as for absorbing the bending stress of the whole box girder on aerodynamic forces.

In the front area has each panel 1 . 2 over a bead 37 for coupling to the front spar 4 by a bolt connection 28 , The rear spar 5 can be considered a one-piece C-profile or, as in 2 represented, in two parts by a main part 5 of the spar and a so-called tolerance corner profile 13 be formed. The rear spar 5 is by means of bolt connection 29 with the monolithic areas 12 the panels 1 . 2 connected.

The 2 and 3 show the connection of the half-rib components 14 . 15 of the first panel 1 or the second panel 2 at a first location by means of a wedge-shaped component 17 in an immovable way. The wedge-shaped component 17 is by means of bolt connection 18 with the half-ribs 14 . 15 connected and allows a compensation in the direction transverse to ribs level 19 to bridge manufacturing tolerances.

Alternatively to the illustrated embodiment, the connection between the half-ribs 14 . 15 also be articulated, z. B. by a hinge.

The 2 and 4 clarify the coupling of the half ribs 14 . 15 on the rear spar 5 and to a steering element for a rudder or a flap in the form of a rudder fork 20 , The half ribs 14 . 15 point through the rear spar 5 and the tolerance corner profile 13 walking half-ribbons 21 on that for the transmission of normal forces 22 with the rudder fork straps 23 by bolt connection 24 are coupled. Such a connection also ensures a tolerated coupling of the half-ribs 14 . 15 with the rudder fork 20 with a possible displacement of the ribs 14 . 15 concerning the rib plane 19 , The lateral force 25 from the oar fork 26 is by bolt connection 27 in the spar 5 initiated.

Thus, the half-rib members are 14 of a panel 1 and the corresponding half-rib members 15 the second panel 2 at the first location, typically only at a single coupling point through the component 17 immovably connected to each other and at a longitudinal direction thereof spaced second location by the rear spar 5 kept at a rigid distance from each other.

The half ribs 14 . 15 have several functions. First, they strengthen the panels 1 . 2 in the sense of a distributed force introduction of normal forces 22 the oar forks 20 in the panels 1 . 2 and help provide additional reinforcement (skin thickening) to the panels required for this purpose 1 . 2 and thus to avoid increased production costs. On the other hand prevent the half ribs 14 . 15 a mutual displacement of the panels 1 . 2 by the action of the forces on the rudder fork 20 and reinforce the respective panel 1 . 2 for the absorption of the local load by air forces. The reinforcement with the ribs 14 . 15 on the panels 1 . 2 also reduces bulging stresses for the sandwich panels 1 . 2 ,

The through the half ribs 14 . 15 and through the monolithic reinforcements 10 . 12 stiffen sandwich panels 1 . 2 can the distributed load by air forces by means of bolt connections 28 . 29 directly on the front and rear struts 4 . 5 forward, without connection between the half rib webs 38 and the spars 4 . 5 (please refer 2 ).

In 5 is a structure-mechanical replacement scheme of the box girder cross-section with the rudder fork 20 in the form of a framework with knots 30 . 31 . 32 . 33 for receiving the rudder fork forces 34 and 35 shown. Here are the half ribs 14 . 15 as a substitute with trusses 30 - 31 and 30 - 32 , and the oar fork 26 as a replacement, as a truss 31 - 32 shown. Thus, the arrangement described above provides a rigid structure. The half ribs 14 . 15 From a structural mechanical point of view, they act both as a frame construction for the absorption of air forces together with the sandwich panels 1 . 2 , as well as trusses for the stiffening of the force absorption at the rudder fork 20 ,

6 shows a second embodiment of the box girder, in which a wedge connection of the half ribs 14 . 15 through a wedge-shaped component 36 outside the front spar 4 is provided. Furthermore, additional bolt connections 39 and 40 between the half rib webs 38 and the front and rear spars 4 . 5 shown.

The outer arrangement of the spline connection can simplify the coupling work (drilling, bolt connection assembly). The additional connection between the half ribs 14 . 15 and the spars 4 . 5 through the bolt connections 39 and 40 can structurally improve the operation of the box girder, on the one hand by eliminating the bending stress of the leading and trailing edges 10 . 12 the sandwich panels 1 . 2 in passing the air forces on the panels 1 . 2 on the spars 4 . 5 , and on the other hand by a more stable positioning of the leading and trailing edges 10 . 12 the panels 1 . 2 and a corresponding increase in the Beulspannungen these panels.

The fiber composite parts of the box girder can be manufactured using both wet and prepreg technology.

Alternatively, the construction described can also be realized in a box girder in metallic structural design.

LIST OF REFERENCE NUMBERS

1

paneling

2

paneling

3

half ribs

4

front spar

5

rear spar

6

outer skin

7

inner skin

8th

foam core

9

flat surface

10

monolithic reinforcement

11

nasal side

12

monolithic reinforcement

13

Toleranzeckprofil

14

half rib

15

half rib

16

belt

17

wedge-shaped component

18

bolt connection

19

ribs level

20

Oarlock

21

Half rib chords

22

normal force

23

Rudergabelgurt

24

bolt connection

25

lateral force

26

Oarlock Steg

27

bolt connection

28

bolt connection

29

bolt connection

30

Truss nodes

31

Truss nodes

32

Truss nodes

33

Truss nodes

34

Oarlock force

35

Oarlock force

36

keying

37

beading

38

Half rib web

39

bolt connection

40

bolt connection

Claims (37)

Box girder of an aerodynamic tensile structure consisting of two load-bearing aerodynamic panels ( 1 . 2 ) with transversely to the span arranged half rib members ( 14 . 15 ) and spanwise first and second spars ( 4 . 5 ) and by connecting elements ( 17 . 18 . 27 . 28 . 29 ; 39 . 40 ), characterized in that the half-rib members ( 14 ) of an aerodynamic panel ( 1 ) and the corresponding half-rib components ( 15 ) of the second aerodynamic panel ( 2 ) at a near the first spar ( 4 ) arranged immovably connected to each other and at a longitudinal direction thereof spaced, near the second spar ( 5 ) arranged second location are held at a rigid distance from each other. Box girder according to claim 1, characterized in that the half-rib members ( 14 . 15 ) are directly connected to each other in the first place. Box girder according to claim 1, characterized in that the half-rib members ( 14 . 15 ) in the first place via an interposed component ( 17 ) are interconnected. Box girder according to claim 3, characterized in that the intermediate component ( 17 ) in the rib plane ( 19 ) is wedge-shaped. Box girder according to one of claims 1 to 4, characterized in that the first connection point with respect to the rib longitudinal direction in the region between the two bars ( 4 . 5 ) within the spar ( 4 ), near which it is located. Box girder according to one of claims 1 to 5, characterized in that the first connection with respect to the rib longitudinal direction outside the first spar ( 4 ), near which it is located. Box girder according to one of claims 1 to 6, characterized in that the half ribs ( 14 . 15 ) a double T-profile with straps ( 16 ), between which the connection of the first connection point is formed. Box girder according to one of claims 1 to 7, characterized in that the connection at the first connection point by bolt connection ( 18 ) is trained. Box girder according to one of claims 1 to 7, characterized in that the connection is articulated at the first connection point. Box girder according to claim 9, characterized in that the connection is made at the first connection point by a hinge. Box girder according to one of claims 1 to 10, characterized in that the connection at the second connection point via a spar ( 5 ) and / or the supporting panels ( 1 . 2 ) is executed. A caddy according to claim 11, characterized in that the connection at the second connection point by bolt connection ( 27 . 29 ; 40 ) is executed. Box girder according to claim 11 or 12, characterized in that the spar ( 5 ) is at the second connection point a spar with a one-piece profile, in particular with a C-profile. Box girder according to claim 11 or 12, characterized in that the spar ( 5 ) at the second connection point a Toleranceckprofil ( 13 ) to compensate for distance tolerances between the first and second panels ( 11 . 12 ) contains. Box girder according to one of claims 11 to 14, characterized in that the half ribs ( 14 . 15 ) at the second connection point in the form of half-ribbons ( 21 ) over the spar ( 5 ) continue. Box girder according to claim 15, characterized in that the connection between the Half-ribbons ( 21 ) and the rudder fork straps ( 23 ) by bolt connection ( 24 ) is executed. Box girder according to one of claims 1 to 15, characterized in that the second connection point with a coupling element for a flap or a rudder, in particular with a rudder fork ( 20 ) is coupled. Box girder according to claim 17 in conjunction with claim 15 or 16, characterized in that the articulation element ( 20 ) via first bolts ( 27 ) with the spar ( 5 ) and second bolts ( 24 ) with the half-ribbons ( 21 ) and / or the panels ( 1 . 2 ) connected is. Box girder according to one of claims 1 to 18, characterized in that the load-bearing panels ( 1 . 2 ) are executed in Stringerversteifungsbauweise. Box girder according to one of claims 1 to 18, characterized in that the load-bearing panels ( 1 . 2 ) are executed in sandwich construction. Box girder according to claim 20, characterized in that the core of the sandwich structure is a foam. Box girder according to claim 20 or 21, characterized in that the inner skin ( 7 ) of sandwich panels ( 1 . 2 ) as a flat surface ( 9 ) is trained. Box girder according to claim 22, characterized in that the half ribs ( 14 . 15 ) have a constant cross section over at least a substantial part of their length. Box girder according to claim 23, characterized in that the ribs ( 14 . 15 ) form several groups, the ribs ( 14 . 15 ) have a group of equal rib heights and cross sections. Box girder according to claim 23 or 24, characterized in that the ribs are manufactured by pultrusion method. Box girder according to one of claims 20 to 25, characterized in that the sandwich panel ( 1 . 2 ) in the front area a monolithic reinforcement ( 10 ) having. Box girder according to one of claims 20 to 26, characterized in that the sandwich panel ( 1 . 2 ) in the back area a monolithic reinforcement ( 12 ) having. Box girder according to claim 26 or 27, characterized in that the sandwich panels ( 1 . 2 ) on the monolithic reinforcements ( 10 . 12 ) by means of bolt connections ( 28 . 29 ) with the respective spar ( 4 . 5 ) are connected. Box girder according to one of claims 1 to 28, characterized in that the panel ( 1 . 2 ) at the end closer to the first joint a bead ( 37 ) for a coupling to the first connection point closer Holm ( 4 ) having. Box girder according to claim 29, characterized in that the coupling of the flange ( 37 ) on the spar ( 4 ) by bolt connection ( 28 . 39 ) is executed. Box girder according to one of claims 1 to 30, characterized in that the half-rib members ( 14 . 15 ) and / or the intermediate component ( 17 ) Tolerances in the direction transverse to the rib plane ( 19 ) are able to compensate. Box girder according to one of claims 1 to 31, characterized in that the box girder is designed in metallic construction. Box girder according to one of claims 1 to 31, characterized in that the box girder is constructed by fiber composite components. Box girder according to claim 33, characterized in that the fiber composite components of the box girder are manufactured in wet technique. Box girder according to claim 33, characterized in that the fiber composite components of the box girder are manufactured in prepreg technique. Box girder according to one of claims 33 to 35, characterized in that the ribs ( 14 . 15 ) with the panels ( 1 . 2 ) are glued. Box girder according to one of claims 33 to 35, characterized in that the ribs ( 14 . 15 ) with the panels ( 1 . 2 ) are linked by co-polymerization.

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