Method of manufacturing stringer for basalt hybrid aircraft

Abstract

FIELD: aerospace industry.SUBSTANCE: invention relates to technological elements made in the form of a T-shaped profile to strengthen the power structure of an aircraft or vessel. A method for manufacturing a basalt hybrid aircraft stringer, comprising manufacturing a composite basalt base in the form of fibre roving impregnated with binder resins, drawing a rod through a die, and cutting the blank. When producing a composite basalt base in the form of fibre roving impregnated with binding resins, basalt powder is first added to the resin and mixed evenly, the profile configuration is achieved by smoothly joining in the transition zone of the wall to the shelf by using profiling rollers of conjugation radii.EFFECT: increased stability of the wall and shelf of the device by improving the rigidity of epoxy hybrid composites.1 cl, 2 dwg

Description

[0001] Technical field

[0002] The invention relates to technological elements in the aerospace industry, made in the form of a T-shaped profile for strengthening the power structure of an aircraft or vessel.

[0003] Technology Level

[0004] A method is known for producing a ship stringer (patent RU 2143365, IPC B63B 3 / 28. Published on 27.12.1999), containing a section with a variable linear dimension, made to strengthen structures in aircraft construction.

[0005] The disadvantage of the known method is the low stability of the wall and shelf of the structure.

[0006] The closest method of implementation is a stringer (patent RU 2492107, IPC B64C 3 / 18. Published 10.09.2013. Bulletin No. 25), characterized by being made of a multilayer composite material, having, in essence, an L-shaped and T-shaped cross-section along its length and a geometry that changes along at least part of its length with an increase in the distance in the direction along its length, and containing a base and a rib extending from the base, a first surface of the base made with the possibility of its adjoining to the structure of the aerospace device, a second surface of the base located on the opposite side from the first surface, a third surface located on or in the rib on one layer of composite material with the first surface, and a fourth surface located on the rib on the same side as the second surface, wherein the above-mentioned change in geometry is made in the form of a displacement of the first surface in the direction towards the second surface,displacement of the fourth surface in the direction of the third surface, and with the possibility of thereby reducing the risk of the formation of unwanted folds, stresses or stretching of the layers of the composite material in the zone of change of the above-mentioned geometry during manufacturing.,

[0007] The disadvantage of the closest device is the low stability of the wall and shelf of the structure.

[0008] Disclosure of invention

[0009] The technical result is to increase the stability of the wall and shelf of the device by improving the rigidity of epoxy hybrid composites.

[0010] The present technical result is achieved in a method for manufacturing a stringer for a basalt hybrid aircraft, comprising manufacturing a composite basalt base in the form of fiber roving impregnated with binding resins, drawing a rod through a die, cutting a blank, wherein during the manufacturing of the composite basalt base in the form of fiber roving impregnated with binding resins, basalt powder is first added to the resin and mixed uniformly, the profile configuration is performed by smooth conjugation in the transition zone of the wall to the shelf by using conjugation radii in profiling rollers.

[0011] Distinctive features are

[0012] When producing a composite basalt base in the form of fiber roving impregnated with binder resins, basalt powder is first added to the resin and mixed evenly. The use of such a technological method increases the stability of the device by improving the rigidity of epoxy hybrid composites [3, 4];

[0013] The profile configuration is achieved by smoothly joining in the wall-to-shelf transition zone using joining radii in the profiling rollers. This maintains the stability of the device connection due to the rigidity of the hybrid epoxy composites in the joining radii by adding basalt powder to the resin.

[0014] A comparison of the claimed solution with analogs and the prototype did not reveal any features that distinguish the claimed solution, which allows us to conclude that it meets the “novelty” criterion.

[0015] Brief description of figures

[0016] Fig. 1 shows an isometric view of a device in a method for manufacturing a stringer for a hybrid basalt aircraft, including: 1 - a wall; 2 - a shelf; 3 - a smooth connection in the transition zone of the wall to the shelf.

[0017] Fig. 2 shows cutout A on the wall of the hybrid basalt-plastic stringer from Fig. 1, including: 4 - basalt roving threads arranged in the required order; 5 - basalt powder.

[0018] Implementation of the invention

[0019] The primary raw material for composite stringer production is basalt strand. Basalt strand is produced by melting basalt and then drawing it into a thread 10 to 20 microns thick. Additionally, the following are required to produce a composite stringer: resins; ethyl alcohol; acetone; and dicyandiamide. Basalt powder is obtained from crushed basalt by grinding it in an AGO-2S planetary ball mill and sifting it to a fraction of 77 microns.

[0020] The manufacturing process for a composite stringer blank is as follows: roving 4 threads are fed from a special creel device to a tensioning mechanism, where they are arranged in the appropriate order. Once arranged in the desired order, the 4 threads undergo a drying and preheating process with hot air. The heated roving is immersed in an impregnation bath containing epoxy resin pre-mixed with powder 5. This material increases the strength, which reduces wear resistance, of the stringer, a fuselage structural element, by improving the rigidity of the epoxy composites through a combination of basalt fibers 4 and basalt powder 5. The continuous composite rod is passed through a drawing mechanism, at the exit of which the rod is cut to the specified blank size. From the bath, the material is pulled through the mill rollers to obtain a specified area and shape in the cross-section of the stringer T-bar blank.During the rolling operation, a wall 1 and a shelf 2 are formed with a profile configuration that is performed by a smooth conjugation 3 in the wall-to-shelf transition zone by using conjugation radii in the profiling rollers that are required by the nonlinear form, for the stability of the wall and shelf of the device by improving the rigidity of the epoxy hybrid by adding basalt powder to the resin.

[0021] The uniaxial compressive strength of basalt is on average 160 MPa, which increases the surface and volumetric stability of the device [5].

[0022] Thus, the claimed method increases the stability of the stringer of a basalt hybrid aircraft by improving the rigidity of epoxy hybrid composites during its operation and eliminates the possibility of its weakening.

[0023] Sources of information

[0024] 1. Patent RU 2143365, IPC B63B 3 / 28. Published 12 / 27 / 1999.

[0025] 2. Patent RU 2492107, IPC B64C 3 / 18. Published 10.09.2013. Bulletin No. 25.

[0026] 3. Hybrid influence of basalt fibers and basalt powder on thermomechanical properties of epoxy composites. Composites Part B: Mechanical Engineering, Vol. 125, 2017, pp. 157-164.

[0027] 4. Gavrilov M.A. Technology of production and chemical-biological stability of epoxy composites based on production waste. Diss. Cand. Tech. Sciences, p. 278 pp. 128, 133-134. http: / / dissovet.pguas.ru / files / 212-184-01 / Gavrilov / Dissertaciya_GavrilovMA.pdf

[0028] 5. Fundamentals of Rock Physics, Geomechanics, and Massif State Management. Portsevsky A.K., Katkov G.A. UMO approval (No. 51-73 of June 28, 2004) Registered with the Federal Education Agency (No. 5374 of November 16, 2005), 120 pp. p. 21.

Claims

A method for manufacturing a stringer for a basalt hybrid aircraft, comprising manufacturing a composite basalt base in the form of fiber roving impregnated with binding resins, passing a rod through a drawing mechanism, cutting a blank, characterized in that during the manufacture of the composite basalt base in the form of fiber roving impregnated with binding resins, basalt powder is first added to the resin and mixed uniformly, the profile configuration is performed by smooth conjugation in the zone of transition of the wall to the shelf by using conjugation radii in profiling rollers.

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