RU196657U1 - Aircraft wing panel - Google Patents

Abstract

The utility model relates to the field of creating aircraft with increased strength, in particular, to reinforcing wing panels of the power frame of an airframe for increasing the load-bearing capacity and stability, as well as for choosing their rational configuration in aircraft units that receive compressive loads in operation. The wing panel consists of typical stringers and the skin integrating them. Stringer profile power set of panels, in turn, combine the limiters of torsional deformations in the form of transverse ties, located in the gap between the ribs of the panels of the power frame. The configuration and fastening of the transverse couplers compensate for the force that occurs when twisting between the stringers of an open asymmetric profile and amounts to at least 0.3% of the calculated longitudinal tensile compressive load. The technical result consists in increasing the strength parameters of the panels during their deformation from the action of compressive forces. 3 ill.

Description

The utility model relates to the field of creating aircraft with increased strength, in particular, to objects of experimental reinforced wing panels of the aircraft, with increased stability and bearing capacity under compression loading, and also serves to select a rational configuration of reinforced power panels with a longitudinal set of asymmetric type profile in the units of the aircraft (LA).

From the existing level of technology (see patent RU 2490513 C2, G01N 3/24, published 08/20/2013), a sample is known for a shear diffusion test of sheet blanks, consisting of two overlapped plates forming a diffusion joint having overlays combined with them, located on the opposite sides of the connection. The length of the working part of the sample is equal to the length of the overlap, which is at least a quarter of the height of the sample, the width of the sample is not less than half the length of the overlap. The known sample does not provide the possibility of reinforcing compressed panels with a longitudinal set of asymmetric profiles that increase the threshold barrier of flexural-torsional loss of stability (IKPU) arising from the longitudinal compression of the power set.

Also from the prior art (see patent RU 127920 U1, G01N 3/24, published May 10, 2013), a test specimen for eccentric compression of I-shaped metal profiles with holes in the corners on the upper and lower surfaces for fixing it in the test device is known, and the device additionally equipped with lower and upper base plates with locking studs.

The specified sample and device do not provide the possibility of reinforcing the compressed panels with transverse bonds that keep the stringer of the longitudinal set from twisting.

In addition, an analog of the claimed technical solution is a sample (device) for testing a reinforced panel, known from patent SU 1840335 A1, G01N 3/08, published 10.10.2006.

The specified sample for testing a reinforced string panel for compression consists of two parallel uncut three-span panels, two extreme and two middle ribs connecting the panels together and two side walls attached to the ribs. The sample is also equipped with support hinge assemblies, the outer clips of which are fixed on the corresponding extreme ribs, and the inner ones on the ends of one of the uncut three-span panels, while the hinge axis lies on the line of intersection of the midplane of the corresponding extreme rib with a plane parallel to the sheathing through the line of centers of gravity panel cross sections. The specified sample does not provide the possibility of reinforcement by transverse ties (ties) of stringers of a compressed longitudinal set.

There is also known a device for compression tests of articulated supports along vertical edges and pinched along loaded edges of PCM plates (see. "Strength and Stability of Elements and Joints of Elements of Aircraft Structures from Composites. Moscow. Fizmatlit. 2013, p. 89-99 )

The specified device does not provide the possibility of reinforcing the compressed stringer panels between the ribs.

Another analogue of the claimed technical solution is a shear testing device for a smooth PCM plate fixed in a rigid square frame with swivel joints in its corners (see "Strength and Stability of Elements and Joints of Aircraft Structures from Composites", Moscow. Fizmatlit. 2013 city, pp. 89-99, pp. 100, 105, 115).

The specified device does not provide the possibility of loading compression panels of aircraft with a high threshold barrier IKPU power set.

An analogue of the claimed technical solution can also be a stand (device), which includes a metal-composite connection, for compression testing of PCM panels (see patent for utility model RU 148805, G01N 3/08, published on December 20, 2014).

The specified device (stand) does not allow to strengthen the experimental design of the aircraft and to obtain a rational strength of the power frame panels.

Another analogue of the claimed technical solution is a device and a sample for compression tests of typical elements of the power frame of an aircraft glider: multi-span reinforced panels in laboratory conditions. For testing, an experimental three-span panel is used, equipped with strain gauges, with transverse ribs or frames attached to it with typical fasteners, side walls, which, in turn, are connected to a second identical panel, forming a closed system in the form of a caisson. Testing of the caisson panels takes place one at a time, while in the average test span, the conditions for supporting the full-scale structural panel at the junction of it with the ribs or frames are implemented, which are close to real (see the scientific journal Research of the Science City, No. 1 (11), 2015, p. 32-39).

The specified device for testing does not provide the possibility of reinforcing the compressed panels, wing and a number of other units of the airframe of the aircraft with ties between the stringers of an open asymmetric profile.

The closest analogue of the claimed technical solution is a sample, for example, a wing panel of an aircraft, for compressive strength testing experimentally supported by stringers, for example, an asymmetric open profile of a panel consisting of two identical parallel three-span panels with an offset middle part on which strain gages are installed. The panels are interconnected by four ribs of the transverse set, interconnected with a typical fastener by a pair of side walls. The panel is loaded using a power drive, for example, a testing machine, by moving the active beam, which includes an adjustable spherical hinge, or by means of exciters associated with the oil pump station (see "Air Fleet Technique", 1986, No. 1, p. 70-73). The specified device does not provide the possibility of reinforcing the compressed panels of the aircraft by transverse ties (ties) between the elements of the longitudinal set of the asymmetric profile of the power frame, increasing the threshold barrier of the IKPU.

The disadvantage of all the above technical solutions is the lack of the ability to reduce the negative impact of IKPU in the compressed panels of the power set of airframe units of the aircraft.

The technical result is to increase the threshold barrier IKPU (strength) of the longitudinal stringer set and the bearing capacity of the compressed panels.

The technical result is achieved by the fact that the wing panel of the aircraft containing stringers of an asymmetric open profile of a longitudinal set and ribs of the transverse set additionally contains limiters of torsional deformations in the form of transverse couplers located between the ribs and rigidly connected to the stringers, while the section of the coupler is determined by the strength conditions

P _{screed poper.} / _{Rpaneli prod.} ≥ 0.003,

Where

P _{screed popper} - the maximum value of the effort of destruction of the screed or plastic deformation of its materials with torsional loss of stability of the profile of the stringers,

P _{panels prod.} - the estimated compressive force in the panels of the compressed plane of the power frame of the wing.

Torsional strain limiters are located in those wing areas where the stringer flexibility is in the range of 27-70.

Brief Description of the Drawings

Details, features, as well as advantages of this utility model follow from the description of an example of the claimed panel using sketches showing:

FIG. 1 - Flexural-torsional buckling of the asymmetric open section of the stringer under the action of a compressive load P;

FIG. 2 - a) Cross connection screed connected to the shelves of stringers Z-shaped section;

b) Communication of a number of stringers installed in series;

c) Communication groups of stringers;

FIG. 3 - Diagrams of deformation of the source material of the power caisson panel. Increasing the threshold barrier for the appearance of IKPU and tensile strength in the compressed force panels of the wing.

The reinforced compressed wing panel contains asymmetric open profile stringers of force longitudinal set 1, sheathing 2, torsional strain limiters in the form of transverse ties 3 located between the ribs along the span edges (the ribs are not shown conditionally), fasteners, for example, bolted (Fig. 2a). The limiters of torsional deformation 3 are located in those areas of the wing where the flexibility of the stringers is in the range of 27-70. The panel of the power frame, for example, the upper surface of the wing, depending on the design features of the design, taking into account operational requirements, can be strengthened by combining the ties of a number of consecutively installed stringers, or by combining groups of stringers in the gap between the ribs (Fig. 2b, c). At the same time, the strength of the transverse anti-torsion bonds (ties) should be at least 0.3% of the calculated longitudinal breaking load on the long panel from the longitudinal flow of compressive forces.

Studies of the strength and stability of model samples of compressed power panels show that the installation of additional cross-links (ties) between the shelves of typical stringers of an asymmetric open profile in the gap between the ribs of a typical panel increases the threshold barrier of the bending-torsional buckling of the stringers of an open asymmetric section of power panels and the level of local loss of stability of the skin and the tensile strength of the panels, for example, the upper surface of the wing.

On the one hand, the larger the spaced areas in the section of the stringer stringers are, the more rigid they are and the greater the load, on the other hand, the higher the vertical walls, the greater the likelihood of “collapsing” stringers at the early stage of deformation of the compressed longitudinal kit (bending-twisting loss of stability).

The simplest and most effective way to hold compressed longitudinal stringers, even with small deviations from the equilibrium position, from blocking, is to install, as a refinement of the original structures, additional anti-torsion ties (ties) that are technologically advanced in production and installation, between the shelves of typical stringers Z -shaped profile between ribs, which allows to increase the strength of compressed panels by at least 10-15%.

So, the technical result is an increase in the threshold barrier of the IKPU (strength) of the longitudinal stringer set and the bearing capacity of the compressed panels is achieved by reducing the effect of twisting of the stringers of an open asymmetric profile, i.e. lowering the critical half-wave length of the IKPU (l _cr .), we increase the critical stress of the ultimate strength.

IKPU occurs in the range of flexibility of the power skeleton panels λ = 27-70 (G. Hertel Mechanical Engineering. 1965), and this is precisely the range in which more than 90% of the compressed airframe panels are located (Fig. 1). Argyris, Flexure-Torsion Failure of Panels, Aircraft Engineering 1954.

The technical result of the claimed utility model is achieved by installing ties between the free shelves of asymmetric open profiles (stringers), either during the initial production of long panels of the power wing box, or, if necessary, improvements that increase the bearing capacity (tensile strength) of the compression stringers.

The technical result is achieved due to the fact that the compressed panel of the wing of the aircraft contains limiters of torsional deformations of stringers, for example, Z-shaped, in the form of transverse ties located between the ribs of the transverse set and rigidly connected to the stringers of the longitudinal set of an asymmetric open profile, for example, bolt fasteners ( Fig. 2a).

Claims (6)

1. The wing panel of the aircraft, containing stringers of an asymmetric open profile of a longitudinal set and ribs of the transverse set, characterized in that it further comprises limiters of torsional deformations in the form of transverse couplers located between the ribs and rigidly connected to the stringers, while the section of the coupler is determined by the strength conditions P _{screed poper.} / P _{panels prod.} ≥0.003 Where P _{screed popper} - the maximum value of the effort of destruction of the screed or plastic deformation of its materials with torsional loss of stability of the profile of the stringers, P _{panels prod.} - the estimated compressive force in the panels of the compressed plane of the power frame of the wing. 2. The wing panel of the aircraft according to claim 1, characterized in that the torsional strain limiters are located in those wing areas where the stringer flexibility is in the range of 27-70.

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