RU2153419C1 - Screen shell of revolution (versions) - Google Patents

Abstract

FIELD: articles made from composite materials; manufacture of cases or compartments of flying vehicles. SUBSTANCE: shell of revolution has many intersecting spiral and circular stiffeners (1, 2) with outer skin 4 whose layers 3 may be fastened by means of circular, spiral or spiral with circular plates (11, 14) made from spirally crossing unidirectional fibers (7, 8). Outer skin may be provided with additional fibers and coat. Shell may be lined with layers of film elastic-flexible or thermoplastic material. EFFECT: increased stiffness; enhanced strength and reliability at minimum mass. 7 cl, 8 dwg

Description

 The invention relates generally to structures made of composite materials and can be used, in particular, in the manufacture of airframes or compartments of aircraft used in rocket or aviation technology.

 Enclosures in the form of a body of revolution made of composite materials are subject to increased requirements for rigidity, strength, and reliability, while the products must have a minimum weight. However, when solving issues of weight reduction, there is a danger of premature destruction of products. Therefore, various reinforcing elements and fastening means are introduced into the shells in the form of a body of revolution, which make it possible to strengthen the transverse bonds between the layers of the composite material. Mechanical methods for enhancing the transverse connections of the layers of the composite material in the structure during the production of shells by winding filamentary materials slow down the process of their manufacture, the formulation of such reinforcements is laborious and technologically complex. Methods of modifying polymer binders used in mesh shells of rotation have practically exhausted their capabilities and are implemented with strict observance of technological regulations. Particularly relevant is the task of creating rigid and durable mesh shells of revolution, in which stiffeners and lining have a layered structure of the composite material.

Known mesh shell of rotation, containing many intersecting spiral and annular stiffeners and covering the outer skin layers with respectively oriented in them intersecting unidirectional threads, fastened with a polymer binder (RF patent N 2107622, IPC ⁶ V 64 C 13/26, 1998). To increase both rigidity and strength between spiral and annular stiffeners in this mesh shell of rotation, based on them and the outer skin layers covering them, fine-mesh layers of intersecting unidirectional threads or woven tapes with a width exceeding the width of the ribbons in the ribs and forming supporting flanges of stiffeners bonded with them and the outer layers of the sheathing with a polymer binder. However, in mesh shells of rotation with sufficiently narrow spiral and ring stiffeners, the technical connection of the layers of the ribs with the skin layers cannot be resolved with such a technical solution, stiffeners crack when sheathed with the maximum possible axial compression loads and peel off the skin, the structure breaks down .

 Similar disadvantages are manifested in other mesh shells of rotation (US patent N 3083864, NKI 220-83, 1963, N 3300354, NKI 156-159, 1967; N 4137354, NKI 428-116, 1979; N 4278485, NKI 156-173, 1981 )

 On experimental samples of mesh shells of revolution (Journal of Advanced Materials (ISSN, 1070-9789) January 1998, Volume 30, No. 1 "Design Damage Toleranec and Filament Wound Attach Fitting for Launch Vehiele", A. Hou, K. Gramoll, pp16 -21) subjected to axial compression tests, confirmation of the influence of the arrangement of spiral and annular stiffeners and the strength of their bonds on the reliability of the structure is obtained.

 The closest analogue, selected as a prototype, adopted the mesh shell of rotation according to the patent of the Russian Federation N 2107622.

 The main objective is to create a mesh shell of revolution based on the use of unidirectional filaments, a polymer binder and new reinforcement structures and the organization of bonds between spiral and ring stiffeners and covering layers of the skin.

 The technical result from the use of the invention is to increase the rigidity, strength and reliability of the mesh shell of rotation, obtaining its minimum mass. The main problem is solved and the technical result is achieved by changing the structure of the reinforcing layers between the covering sheathing layers and the spiral and ring stiffeners, introducing reinforcing sheathing layers into the layers of stiffening ribs with three technical solutions.

 The first option is in a mesh shell of rotation, containing many intersecting spiral and annular stiffeners and the outer skin layers covering them with intersecting unidirectional threads respectively oriented in them, fastened with a polymeric binder, the outer skin covering layers are made on the outer surface side of the intersecting spiral and annular stiffeners in the form of annular floorings of spiral crossover unidirectional threads placed between the annular ribs ty, with an overlap of their edges on the ring stiffeners, fixed by loops of spirally intersecting threads for unidirectional threads of the ring stiffeners.

 The second option is in a mesh shell of rotation, containing a lot of intersecting spiral and annular stiffeners and the outer skin layers covering them with intersecting unidirectional threads respectively oriented in them, fastened with a polymeric binder, the outer skin covering layers are made on the outer surface side of the intersecting spiral and annular stiffeners in the form of spiral decks of spirally intersecting unidirectional threads placed between spiral ribs awn in each of their directions, with an overlap of their edges on spiral stiffeners, fixed by loops of spirally intersecting threads for unidirectional threads of spiral stiffeners.

 The third option is in a mesh shell of rotation, containing many intersecting spiral and annular stiffeners with intersecting unidirectional threads respectively oriented in them, fastened with a polymeric binder, the covering layers of the outer skin are made on the side of the outer surface of the intersecting spiral and annular stiffeners in the form of spiral and ring decks spirally intersecting unidirectional filaments, the spiral decks being placed between the spiral ribs and in each of their directions with overlapping of their edges on spiral stiffeners, ring decks cover spiral decks and are placed between ring stiffeners with overlapping of their edges on annular stiffeners, helically intersecting unidirectional threads of spiral decks are looped for unidirectional threads of spiral ribs helically intersecting unidirectional filaments of annular decks are looped to unidirectional filaments of annular stiffeners.

 In the shells of all variants, the covering layers of the outer skin over the decks of spirally intersecting unidirectional yarns can be made in the form of unidirectional yarns of the circumferential direction fastening them or with a protective coating of elastic-elastic or thermoplastic material, respectively, such as rubber or polyurethane; floorings of helically intersecting unidirectional filaments along the inner contour from the side of the inner surface may be lined with a layer of polymer binder or a layer of film thermoplastic or elastic-elastic material; spiral and circular stiffening ribs along the inner contour can be lined with a layer of film of elastic-elastic or thermoplastic material, respectively, such as rubber or polyurethane with mesh material from intersecting threads introduced into it.

Distinctive features of the mesh shell of rotation are the following features:
first option:
- the implementation of the covering layers of the casing on the side of the outer surface of the intersecting spiral and annular stiffeners in the form of annular floorings of spirally intersecting unidirectional threads,
- the placement of the annular decking of spiral intersecting unidirectional threads between the annular stiffeners,
- overlap of the edges of the ring decks on the ring stiffeners,
- fastening of helically intersecting unidirectional filaments of annular flooring loops for unidirectional filaments of annular stiffeners.

second option:
- the implementation of the covering layers of the casing on the side of the outer surface of the intersecting spiral and annular stiffeners in the form of spiral decks spiraling intersecting unidirectional threads,
- placement of spiral decks of spiral crossover unidirectional threads between spiral stiffeners of each direction,
- overlap of the edges of the spiral decks on the spiral stiffeners,
- fastening of spiral intersecting filaments of spiral decks with loops for unidirectional filaments of spiral stiffeners.

third option:
- the implementation of the covering layers of the sheathing on the side of the outer surface of the intersecting spiral and annular stiffeners in the form of spiral and annular floorings of helically intersecting unidirectional threads,
- placement of spiral decks between spiral stiffeners in each direction,
- overlap of the edges of the spiral decks on the spiral stiffeners,
- coverage of spiral decks ring decks,
- placement of ring decks between the ring stiffeners,
- overlap of the edges of the ring decks on the ring stiffeners,
- fastening helically intersecting unidirectional threads of spiral decks with loops for unidirectional threads of spiral stiffeners,
- fastening of helically intersecting unidirectional filaments of annular flooring loops for unidirectional filaments of annular stiffeners.

Additional distinctive features of the mesh shell of rotation of all options are the following features:
- the implementation of the coating layers of the outer skin on top of the flooring from spirally intersecting unidirectional yarns in the form of unidirectional yarns of the circumferential direction fastening them,
- the implementation of the coating layers of the outer skin with a protective coating of elastic material or thermoplastic material, respectively, such as rubber or polyurethane,
- lining the flooring of spiral crossover unidirectional filaments along the inner contour from the side of the inner surface with a layer of a polymer binder or a layer of a film of thermoplastic or elastic material,
- lining of spiral and annular stiffeners along the inner contour with a layer of film of elastic or thermoplastic material, respectively, such as rubber or polyurethane with the introduction of a mesh material from intersecting threads.

 These distinctive features are significant, since each of them individually and jointly aimed at solving the problem and achieving a new technical result. In the proposed variants of the mesh shell of rotation between the stiffeners of the corresponding direction, the inner layers of the outer skin are made in the form of decks of spirally intersecting unidirectional filaments with an overlap of their edges on the stiffeners and fastening them with loops for unidirectional threads of the corresponding stiffeners. This solution allows you to securely fasten the outer skin with stiffeners in the radial, axial and circumferential directions and to provide such bonding with increased structural strength. Depending on the load of the mesh shell of rotation, taking into account the proposed technical solution, various combinations of structures for their reinforcement can be obtained, which opens up wide possibilities for their application in the considered field of technology. The introduction in the outer sheathing of circumferential yarns on top of the decking from spirally intersecting unidirectional yarns allows them to be compacted to minimum thicknesses and to ensure reliable bonding with stiffeners. The protective coating of the layers of decking from spiral crossover unidirectional threads on both the outer and inner surfaces allows sealing the mesh shell of rotation. The lining of stiffeners in the form of a mesh material and a polymer matrix eliminates cracking of stiffeners when loading the shell, increases their stability and resistance. The mesh shells of rotation with the proposed reinforcement structures open up a new direction for their modifications.

 Distinctive essential features are new, since their use in the prior art, analogues and prototype, was not found, which allows us to characterize the mesh shell of rotation in the proposed set of essential features in accordance with the criterion of "novelty."

 A single set of new essential features with common essential known features allows us to solve the problem of obtaining mesh shells of rotation of high rigidity, strength and reliability. New technical solutions in the mesh shells of rotation are the result of analysis and experimental research, a creative contribution to the development and creation of new modifications of the mesh shells of rotation, obtained without the use of standards or any recommendations in the art, are non-obvious and original, together significant features meet the criterion of "inventive step".

 In FIG. 1 shows a General view of the mesh shell of rotation with many intersecting spiral and annular stiffeners and outer skin, figure 2 - the first version of the mesh shell of rotation with ring decking of the covering layers of the outer skin, figure 3 - the second version of the mesh shell of rotation with spiral decking covering layers of the outer skin, in FIG. 4 - the third version of the mesh shell of rotation with the covering layers of the outer skin of a combination of spiral and annular decking, Fig.5 is a diagram of the reinforcing of the coating layers of the outer skin with the introduction of unidirectional filaments of circumferential direction, Fig.6 - the implementation of the outer skin with an outer coating Fig.7 is a diagram of the cladding of the outer skin along the inner contour, Fig.8 is a diagram of the cladding of spiral and annular stiffeners in the mesh shell of rotation along the inner contour.

 The mesh shell of rotation (Fig. 1) contains many intersecting spiral and annular stiffening ribs 1,2 and the layers of the outer skin 4 covering them 3 with the corresponding oriented unidirectional crossing threads 5,6,7,8, bonded with a polymer binder 9. Covering layers 3 of the outer skin 4 (Fig. 1) are made from the side of the outer surface 10 of intersecting spiral and annular stiffening ribs 1.2 in the form of annular floorings 11 (Fig. 2) of spirally intersecting unidirectional threads 7.8 placed between the annular and stiffeners 2, with an overlap of 12 of their edges on the annular stiffeners 2, fixed by loops 13 of spirally intersecting strands 7.8 for unidirectional strands 6 of the annular stiffeners 2 (Fig. 6). The covering layers 3 of the outer skin 4 (Fig. 1) can be made on the side of the outer surface 10 of the intersecting spiral and annular stiffeners 1,2 in the form of spiral decks 14 (Fig. 3) of spirally intersecting unidirectional threads 7.8 placed between the spiral ribs stiffness 1, fixed by loops 16 of spirally intersecting unidirectional threads 7.8 for unidirectional threads 5 of spiral stiffening ribs 1 (Fig.6). The covering layers 3 of the outer skin 4 (Fig. 1) can be made on the side of the outer surface 10 of intersecting spiral and annular stiffeners 1,2 in the form of a combination of spiral and annular floorings 14 and 11 (Fig. 4) of spirally intersecting unidirectional threads 7,8 moreover, the spiral decks 14 are placed between the spiral stiffeners 1 in each direction with an overlap of 15 of their edges on the spiral stiffeners 1, the annular decks 11 cover the spiral decks 14 and are placed between the annular stiffeners 2 with an overlap 12 of their edges to ring stiffeners 2, spiral cross-over unidirectional threads of 7.8 spiral deck 14 are looped 16 for unidirectional threads 5 of spiral reinforcement 1, and spiral cross-over unidirectional threads of 7.8 ring deck 11 are looped 13 to unidirectional threads of 6 ring ribs stiffness 2 (Fig.6). In the mesh shell of rotation (Figs. 1-4), the outer layers 3 covering layers 3 on top of the decks 11.14, or a combination thereof of spirally intersecting unidirectional filaments 7.8, are made in the form of unidirectional filaments fastening them 17 in a circular direction (Fig. 5). The same coating layers 3 can be made with a protective coating 18 (Fig. 6) of an elastic-elastic or thermoplastic material, respectively, such as rubber or polyurethane. The floorings 11,14 or a combination thereof in the covering layers 3 of the outer skin 4 made of spiral crosses of unidirectional filaments 7.8, may be lined with a layer 21 of a polymeric material or a film of thermoplastic or elastic material along the inner contour 19 from the side of the inner surface 20. Spiral and ring stiffeners of 1.2 mesh shells of revolution along the inner contour 22 can be lined with a layer 23 of a film of elastic or thermoplastic material, respectively, such as rubber or polyurethane with mesh material 24 made of intersecting threads introduced into it (Fig. 8).

 The manufacture of the mesh shell of rotation in the proposed versions is made by winding threads, decking on a special mandrel.

 The functioning of the mesh shell of rotation consists in the simultaneous connection to the work of all helically intersecting and annular stiffeners with external casing due to the introduction of decking from helically intersecting unidirectional threads and fastening them with loops with unidirectional threads of ring and / or spiral stiffeners.

 The tests of mesh shells of rotation confirmed their high strength and reliability. The tests of the shells were carried out for compression in the axial direction. The implementation of the proposed technical solutions allows you to get high-quality products for the hull compartments of aircraft.

 Thus, the new technical solution described above in terms of design is technologically new and efficient compared to the prior art.

 The scope of the invention should be understood broader than the specific implementation given in the description, formula and drawings. It should be borne in mind that the form of the invention is only possible preferred options for its implementation, there may be various embodiments of the invention in relation to the shape, size and location of the individual elements, if all this does not go beyond the scope set forth in the claims.

 In addition, the proposed technical solution is not limited to their use in mesh shells of rotation for aircraft and can be used in other areas of technology where the use of shells in the form of bodies of revolution from composite materials of increased strength, tightness and reliability and other properties described in the materials is required applications.

 The new technical solution in the proposed combination of essential features meets the criterion of "industrial applicability", i.e. level of invention.

Claims (7)

 1. A mesh shell of revolution, containing many intersecting spiral and annular stiffeners and the outer skin layers covering them with intersecting unidirectional threads correspondingly oriented in them, fastened with a polymer binder, characterized in that the outer skin covering layers are made on the outer surface side of the intersecting spiral and annular stiffeners in the form of annular decking of spiral intersecting unidirectional threads placed between the annular ribs w stiffness with an overlap of their edges on the ring stiffeners, fixed by loops of spirally intersecting threads for unidirectional threads of the ring stiffeners.  2. The mesh shell of rotation, containing many intersecting spiral and annular stiffening ribs and the outer skin layers covering them with intersecting unidirectional threads respectively oriented in them, fastened with a polymer binder, characterized in that the outer skin covering layers are made on the outer surface side of the intersecting spiral and annular stiffeners in the form of spiral decks of spirally intersecting unidirectional threads placed between spiral ribs stiffness in each their direction with their edges overlapping on spiral ribs intersecting helically looped strands of unidirectional filaments of spiral ribs.  3. The mesh shell of rotation, containing many intersecting spiral and annular stiffeners and the outer skin layers covering them with intersecting unidirectional threads respectively oriented therewith fastened with a polymer binder, characterized in that the outer skin covering layers are made on the outer surface side of the intersecting spiral and annular stiffening ribs in the form of spiral and annular floorings of spirally intersecting unidirectional threads, moreover, spiral floorings placed between spiral stiffeners in each direction with an overlap of their cuts on spiral stiffeners, ring decks cover spiral decks and placed between ring stiffeners with overlap of their edges on annular stiffeners, unidirectional threads of spiral decks spiraling intersecting are fixed with single-loop threads stiffening ribs, and spirally intersecting unidirectional filaments of annular decks are looped to unidirectional filaments of rings stiffening ribs.  4. The shell according to any one of claims 1 to 3, characterized in that the covering layers of the outer skin over the decking of spirally intersecting unidirectional filaments are made in the form of unidirectional filaments of circumferential orientation.  5. The shell according to any one of claims 1 to 4, characterized in that the covering layers of the outer skin are made with a protective coating of an elastic material or thermoplastic material, respectively, such as rubber or polyurethane.  6. A sheath according to any one of claims 1 to 5, characterized in that the floorings of helically intersecting unidirectional filaments along the inner contour from the side of the inner surface are lined with a layer of polymer binder or a layer of thermoplastic film or elastic material.  7. A shell according to any one of claims 1 to 6, characterized in that the spiral and annular stiffeners along the inner contour are lined with a layer of film of elastic or thermoplastic material, respectively rubber or polyurethane, with mesh material from intersecting threads introduced into it.

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