RU2643234C1 - Stand for testing the design of the flying machine for mechanical strength under the action of the bending moment - Google Patents

Abstract

FIELD: testing equipment.

SUBSTANCE: device contains a snap-in device for fixing the tested structure and a loading system. The loading system is located under the installation zone of the said structure and includes a drive arm connected to the power drive mounted on the base and mounted distribution traverses thereon. Distribution traverses serve to transfer the load to the tested structure through distribution beams, each pair of which is connected by means of links with a respective distributing beam. On the rack there is a carriage that moves vertically along it. The console is fixed on the carriage, located above the distribution beams. Moving upwards, the console raises the distributing beams to the upper position, at which mounting of the stand parts is carried out. When the console moves down, the beams are synchronously lowered to the lower position, in which contact of the beams with the test structure is ensured.

EFFECT: simplification of service of the stand, creation of loading on tested design in a wide range and maintenance of a steeples adjustment of loading.

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Description

FIELD OF THE INVENTION

The invention relates to the field of testing equipment and, in particular, to a stand intended for testing the aircraft structures for mechanical strength under the action of a bending moment. Among the designs whose tests can be carried out at the proposed stand include mainly the wing of the aircraft (or parts thereof, for example, a caisson), as well as elements of the wing mechanization: interceptor, aileron, flap, etc.

State of the art

A device for testing the strength under the action of the bending moment of the wing structure of the aircraft, having a base on which the upper and lower multi-link frames located on the side of the upper and lower wing skins are supported through hydraulic power exciters. On the frames there are elastic chambers in contact with the surfaces of the skin and connected to a pressure source. During the tests, the necessary distribution of loads on the wing surface is achieved by moving the upper and lower multi-link frames using hydraulic force exciters and simultaneously supplying the working medium from the pressure source to the elastic chambers (see SU 581787 A1). The device has a bulky, unreliable and inconvenient to use design due to the use of a two-sided loading circuit of the test object (from the upper and lower casing), requiring the use of a double set of loading means, due to the significant number of hydraulic force exciters, the use of elastic chambers and additional use of the source pressure for supplying a working medium to the chambers.

A known installation for testing mechanical strength under the action of the bending moment of the wing of an aircraft, containing equipment for fixing the test object in a horizontal position during testing and a loading system connected to a device for creating a mechanical load and with elements of local action on the wing (load distribution clamps), located along the wing and covering it in the transverse direction. The loading system is formed by a plurality of traverses connecting the mechanical load generating device (power drive) with distribution clamps (see US 4481817 A). A disadvantage of the known design is that the traverses forming the installation have a complex orientation in space, which greatly complicates the maintenance of the installation.

A known bench for testing the design of the bar type for mechanical strength under the action of a bending moment, containing equipment for fixing the test structure in a horizontal position during testing and a loading system connected to a device for creating a mechanical load (power drive) and with elements of local influence on the test structure ( load distribution beams) arranged in a row under the structure in the transverse direction. The loading system includes a drive traverse connected to the power drive, and associated distribution traverses, the rods of which are connected to the load beams (see RU 2539835 C1). The scheme used to create a load on the test structure used in the stand has significant drawbacks. The loading system is located above the test structure, and the load on the structure is directed upward, which requires the use of a very powerful bulky carrier frame with large dimensions in the stand (this can be clearly seen in Fig. 1 of the patent). In addition, the maintenance of such a stand, in which the nodes and mechanisms are at a considerable height, is very difficult, because it will require the use of special platforms, lifts, stairs.

As the closest analogue to the claimed stand adopted installation for testing the mechanical strength under the action of the bending moment of the wing of the aircraft, containing a base with a mounted lift, a stand mounted on the base and serving to secure the test wing above the lift, and a loading system (CN204422347 U , publ. 24 06 2015). The loading system includes massive heavy blocks placed in a row on the platform of the elevator and under the wing, and load distribution beams by the number of blocks installed in a row on the upper skin of the wing in the transverse direction to it and connected via cables to the blocks. When lowering the elevator, the platform moves down and ceases to support the blocks, which as a result become suspended and transfer the necessary load to the beams that load the wing. Despite the fact that the loading system located under the wing is, in comparison with the design according to RU 2539835, more accessible for installation work during operation of the installation, however, the use of massive heavy blocks in this system significantly complicates the maintenance of the installation. With this embodiment, the ability to adjust the magnitude of the loads transmitted to the wing is limited. Changing the load is possible only by changing the mass of the blocks due to, for example, hanging additional loads on them, which, on the one hand, is extremely inconvenient and time-consuming, and does not make it possible to adjust loads in a wide range, and on the other, such adjustment is stepwise and will not allow create a stepless load on the test structure (as required by the test conditions), significantly limiting the technological capabilities of the installation.

Disclosure of invention

The objective of the invention is to develop a bench for testing the mechanical strength of aircraft structures with the creation of a stress-strain state similar to the work of the aircraft structure under the action of a bending moment in real conditions.

The technical result achieved by the implementation of the claimed invention is to simplify the maintenance of the stand during its operation, while expanding the technological capabilities of the stand by creating a load on the tested structure in a wide range and providing stepless load adjustment.

To achieve the specified technical result, a stand is proposed for testing the aircraft design for mechanical strength under the action of a bending moment, containing a base with a stand fixed on it, supporting equipment for fixing the test structure, distribution beams located one above the other on the upper surface of the specified structure in a row its entire length in the transverse direction relative to the longitudinal axis of the structure, a power drive mounted on the base, and a system on loading placed under the installation zone of the specified design and connected to the distribution beams. In contrast to the known stand, the loading system of the claimed stand contains a drive beam connected to the power drive, and distribution travers mounted on it, each of which is connected via rods to each pair of distribution beams

Preferably, the stand further comprises a carriage mounted on a rack with the possibility of vertical movement, with a console mounted thereon, located above the distribution beams.

The stand also additionally contains pendants mounted on the console from the side of its surface facing the distribution beams.

Each distribution beam preferably has a pair of holders located on different sides of the vertical axis of symmetry of the beam, in each of which a roller is installed with the possibility of free rotation.

The bench preferably contains at least two support nodes for supporting the test structure, including a hanging holder fixed to the console and a support roller located at its end.

The support roller is preferably adapted to be adjusted in height and / or installation angle.

The power drive is preferably a hydraulic cylinder.

Brief Description of the Drawings

The invention is illustrated by drawings, where:

In FIG. 1 shows a proposed stand, front view;

In FIG. 2 - proposed stand, side view;

In FIG. 3 is a view along AA in FIG. one;

In FIG. 4 is a view along BB in FIG. 3.

The implementation of the invention

The proposed stand provides the ability to test the design of the aircraft for mechanical strength under the action of a bending moment. Tests are carried out to determine the SSS of the elements of the test structure, assess their rigidity and are associated with the need to conduct a structural strength analysis to describe the structural failure process with subsequent experimental verification of the results.

The bench contains a base 1 with a vertical strut 2 fixed on it, in the upper part of which there is a power tool 3, which ensures the fixation of the structure during its testing, and a loading system. Power equipment 3 should provide for the fixing of the tested structures is the same as in the real structure of the aircraft.

The following is a description of the proposed stand is shown on the example of using, as a test design, the wing box of the aircraft.

The loading system is located in the lower part of the stand on the base 1 under the tested structure (under the caisson 4). The specific loading system shown in FIG. 1, 2, includes a drive traverse 5 and two distribution traverses 6 and 7, the name of which is due to the function they perform - load distribution from the power drive (hydraulic cylinder) 10 to the sections of the test wing box 4.

The beam 8 of the drive beam 5 is connected through a plug 9 to the rod of the hydraulic cylinder 10, mounted through a force sensor 11 on the support node 12 mounted on the base 1. The beam 13 of each distribution beam 6, 7 is a cross with sidewalls 14 and a jumper 15.

At the end sections of the beam 8 at equal distances from its vertical axis 16 (through which the axis of the hydraulic cylinder 10 passes), rods 17 and 18 are fixed. The end of the rod 17 is connected to the middle of the bridge 15 of the beam 13 of the distribution beam 6 and, accordingly, the end of the rod 18 is connected to the middle of the bridge 15 of the beam 13 distribution beam 7.

On each sidewall 14 of the beam 13 of the distribution beam 6, on either side of the bridge 15 and at the same distance from the vertical axis of symmetry of the bridge, two rods 19 are fixed. Similarly, on each side of the beam 14 of the beam 13 of the distribution beam 7, on opposite sides of the bridge 15 and at the same distance from the vertical axis of symmetry of the jumper, two rods are fixed 20. The indicated distances for both distribution traverses are sustained in the same size.

The load created by the loading system is transmitted to the tested structure by distribution beams 21. The beams 21 are mounted on the side of the upper surface 22 of the wing box 4 in the transverse direction to it and are arranged in a row one after another and parallel to each other from the fixation section of the tested structure in the snap 3 and to the distal, with respect to the fixation site, part 23 of the wing box. In the case of testing structures with an aerodynamic profile (for example, wing structures), the surfaces of the distribution beams 21 adjacent to the curved surface of such a structure have a configuration that ensures that they fit snugly against this curved surface (in particular, to the wing skin).

For the distribution beam 6, two opposite rods 19, mounted on different sides 14 of the beam 13 of the beam 6, are connected at their ends to the end sections of the distribution beam 21a, and two other opposite rods 19, mounted on different sides 14 of the beam 13 of the beam 6, are connected at their ends to end portions of adjacent distribution beam 21b.

Similarly, for the distribution beam 7, two opposite rods 20 fixed on different sides 14 of the beam 13 of the beam 7 are connected at their ends to the end sections of the distribution beam 21c, and two other opposite rods 20 mounted on different sides 14 of the beam 13 of the beam 7 are connected by their ends to end portions of adjacent distribution beam 21d. Thus, a pair of adjacent distribution beams 21a, 21b is connected to the distribution beam 6, and a pair of adjacent distribution beams 21c, 21d is connected to the distribution beam 7.

On each distribution beam 21 a pair of holders 25 and 26 are mounted, located on different sides from the vertical axis of symmetry 27 of the beam. In each of the holders mounted freely rotating roller 28.

A vertically oriented carriage 29 is located on a vertical strut 2 on the side opposite to the power tool 3. The carriage has the ability to move in a vertical plane relative to the strut 2 along the guide rollers 30 provided on the strut. The movement of the carriage 29 is provided by the handle 31 of the screw mechanism 32. A console 34 is fixed to the upper end of the carriage 29, which extends over the distribution beams 21a to 21d. In order to reduce weight, the carriage 29 and the console 34 are made frame type.

Suspensions are welded to the console 34 from the side of its surface facing the distribution beams 21a - 21d. A pair of suspensions 35 and 36 are provided for each distribution beam 21a - 21d, which are located on different sides from the vertical axis of symmetry 27 of the beam and further from this axis than the holders 25 and 26.

Holes 37 are provided in the suspensions 35 and 36, and slots are provided in the holders 25 and 26. An axis 39 passes through the holes of each pair of suspensions and through the slots of each pair of holders.

To ensure the convenience of supplying the test structure to the power tool 3 and holding it in the process of fixing in the tool, at least two support nodes are used. Each of the nodes is formed by a pair of hanging holders 40 mounted on a console 34 and oriented vertically downward, and supporting elements located at the ends of the holders, which are removable freely rotating rollers 41. The position of the rollers 41 is adjustable both in height and in angle of installation.

Testing the design of the aircraft at the proposed stand is as follows.

In the process of preparing the wing box for testing, strain gauge sensors are installed on the sections of the box, depending on the specified test conditions.

At the initial stage, the assembly of the stand nodes is carried out. In this case, the console 34 is set to its highest position by moving it upward by rotating the handle 31 of the screw mechanism 32. To the console 34 in this position, the distribution beams 21 are suspended. For this, with respect to each distribution beam 21a to 21d, through the slots in the holders 25 and 26 and through the holes 37 in the suspensions 35 and 36 pass the axis 39. The distribution beams 21a - 21d are raised, hang securely on their axles 39, and you can begin installation work. Distribution traverses 6 and 7 must be connected to the distribution beams 21a - 21d. Rods 19 (for beams 21a, 21b) and rods 20 (for beams 21c, 21d) are connected to the end sections of the distribution beams 21a - 21d. To the free ends of the rods are connected the beams 13 of the distributing traverse 6 and 7, to which, in turn, the rods 17, 18 of the drive traverse 5 are fixed, mounted on the hydraulic cylinder 10.

As already noted, at this stage, the console 34 is in its upper position. The removable rollers 41 are mounted on the hanging holders 40 and the test structure is rolled onto the rollers 41 (wing box 4). By rotating the handle 31 of the screw mechanism 32, the carriage 29 is moved downward. Together with the carriage 29, the console 34 with the distribution beams 21a - 21d suspended on it is lowered to the position where the beams 21a - 21d come into contact with the surface of the test caisson 4. Additionally lower the console 34 even lower, to enable the axles 39 to be released and removed.

At the end of installation, they begin to test the coffer 4 fixed in the snap-in 4. Turn on the hydraulic drive. When lowering the rod of the hydraulic cylinder 10, the drive beam 5 and the distribution beam 6 and 7 move downward. The load created by the hydraulic cylinder 10 is transmitted through the said beam to the distribution beams 21a - 21d, which transfer the load to the caisson 4, subjecting it to intense bending. During the test, the load is changed in accordance with the test procedure. During the tests, the effective load and deformation of the test structure are recorded according to the readings of the strain gauges.

Claims (12)

1. A bench for testing the design of an aircraft for mechanical strength under the action of a bending moment, containing a base with a stand fixed on it, carrying a snap for fixing the test structure, distribution beams located above the upper surface of the specified structure in a row one after another along its entire length in the transverse direction relative to the longitudinal axis of the structure, a power drive mounted on the base and a loading system located under the installation zone of the specified design and connected to the distribution beams, characterized in that the loading system contains a drive beam connected to the power drive, and distribution traverses mounted on it, each of which is connected by means of rods to each pair of distribution beams. 2. The stand under item 1, characterized in that it further comprises a carriage mounted on a rack with the possibility of vertical movement, with a console mounted on it, located above the distribution beams. 3. The stand according to claim 2, characterized in that it further comprises pendants fixed to the console from the side of its surface facing the distribution beams. 4. The stand according to claim 1, characterized in that each distribution beam has a pair of holders located on opposite sides of the vertical axis of symmetry of the beam, in each of which a roller is installed with the possibility of free rotation. 5. The stand according to claim 1, characterized in that it comprises at least two support nodes for supporting the test structure, including a hanging holder fixed to the console and a support roller located at its end. 6. The stand according to claim 5, characterized in that the support roller is made with the possibility of adjustment in height and / or installation angle. 7. The stand under item 1, characterized in that the power drive is a hydraulic cylinder.

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