Metal-lining-containing fiber winding shell for relieving metal deformation and buckling and design method of metal-lining-containing fiber winding shell

Abstract

The invention relates to a metal-lining-containing fiber winding shell for relieving metal deformation and buckling and a design method. The metal-lining-containing fiber winding shell comprises a metal lining, an elastic layer and a fiber shell structure. The elastic layer is located between the metal lining and the fiber shell structure and smoothly covers the lap joint position of the shell barrel section and the end socket. The inner surface of the elastic layer adheres to the outer surface of the metal lining, and the outer surface of the elastic layer adheres to the inner surface of the fiber shell structure. The thickness of the elastic layer is uniform and is 5%-10% of the total thickness of the metal lining and fiber shell structure, and the elastic layer is made of EPDM rubber materials. By adding the middle elastic layer, deformation and buckling of the metal lining are relieved, the possibility of shell debonding is reduced, and the product performance of the fiber-wound gas cylinder containing the metal lining is effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines and relates to a fiber-wound casing containing a metal liner for alleviating deformation and buckling and a design method thereof. Background Art

[0002] Fiber-wound gas cylinders with linings are generally required to have sufficient strength and good airtightness. Currently, the commonly used lining materials are metal linings and plastic linings. Plastic linings have the disadvantages of low collision strength, poor airtightness, and temperature sensitivity. Composite gas cylinders with metal linings have the advantages of good airtightness and excellent corrosion resistance. They have been widely used in the aerospace and weapons industry. The lining is an isotropic material and mainly plays a sealing role. The outer fiber layer mainly plays a load-bearing role. The two work together to give the wrapped container good mechanical properties.

[0003] During the production process of composite pressure vessels, the pressure vessels are often first subjected to a self-tightening process so that the excellent performance of the fiber can be fully exerted, thereby significantly improving the bearing capacity of the pressure vessel. However, due to the mismatch between the performance of the metal liner and the composite material, the metal liner will produce irreversible plastic deformation during the self-tightening process, while the composite material is still within the elastic range. After the self-tightening pressure is unloaded, there is a compressive force between the liner and the composite material. The metal liner is prone to instability at high compressive stress, thus affecting the service life of the pressure vessel. Since the metal liner is very thin, compressive stress is generated inside the metal liner under the action of fiber tension during the winding process. As the winding tension increases, the weakening effect of the stress stiffness matrix increases. When a certain load is reached, its weakening effect exceeds the inherent stiffness of the metal liner, and the metal liner buckles and fails. However, the current research on composite pressure vessels by domestic and foreign scholars focuses on strength analysis and material failure, and the research and optimization of liner stability are relatively scarce. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, and to propose a fiber-wound shell containing a metal liner and a design method for alleviating metal deformation and buckling for composite material gas cylinders containing metal linings. By adding an intermediate elastic layer, the deformation and buckling of the metal liner are alleviated, the possibility of shell debonding is reduced, and the product performance of the fiber-wound gas cylinder containing a metal liner is effectively improved.

[0005] The technical solution of the present invention is: a fiber-wound shell containing a metal liner for alleviating metal deformation and buckling, comprising a metal liner, an elastic layer, and a fiber shell structure; the inner surface of the elastic layer is bonded to the outer surface of the metal liner, and the outer surface of the elastic layer is bonded to the inner surface of the fiber shell structure; the thickness of the elastic layer is uniform, which is 5% to 10% of the total thickness of the metal liner + fiber shell structure, and smoothly covers the overlap position of the shell barrel section and the head.

[0006] Furthermore, the material of the elastic layer is selected from one of EPDM rubber material and nitrile rubber material.

[0007] Furthermore, the preparation of the elastic layer includes the following two methods:

[0008] One is molded into a rectangular sheet, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a hand-pasting process; the other is molded into a narrow strip, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a winding process.

[0009] A method for designing a filament-wound shell containing a metal liner for alleviating metal deformation buckling comprises the following steps:

[0010] Complete the manufacturing process of metal lining;

[0011] Grinding the outer surface of the metal lining to increase the roughness of the outer surface of the metal lining;

[0012] Making an elastic layer of equal thickness, the thickness of the elastic layer is 5% to 10% of the total thickness of the metal lining + fiber shell structure;

[0013] After brushing glue on the outer surface of the metal lining, evenly paste the elastic layer of equal thickness. During the pasting process of the elastic layer, ensure that the elastic layer completely covers the metal lining and ensure that the elastic layer at the overlap position of the shell section and the head is smooth and has no warping edges;

[0014] Fiber winding is performed after applying glue on the outer surface of the elastic layer;

[0015] After the shell is wound, the entire shell is placed in a curing oven for curing.

[0016] Furthermore, the material of the elastic layer is selected from one of EPDM rubber material and nitrile rubber material.

[0017] Furthermore, the preparation of the elastic layer includes the following two methods:

[0018] One is molded into a rectangular sheet, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a hand-pasting process; the other is molded into a narrow strip, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a winding process.

[0019] Furthermore, the curing temperature covers the vulcanization temperature of the elastic layer, and during the curing process, the elastic layer completes the vulcanization process along with the curing furnace.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] (1) The present invention reduces the possibility of buckling failure of the metal liner due to instability by adding an intermediate elastic layer and specifically designing the material and thickness of the intermediate elastic layer, thereby effectively improving the product performance of the fiber-wound gas cylinder containing the metal liner;

[0022] (2) The elastic layer material of the present invention is easy to obtain, and the preparation process of the fiber-wound shell with the elastic layer added is innovative, so the process is highly feasible and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of a conventional fiber winding structure containing a metal liner;

[0024] Figure 2 A schematic diagram of a fiber winding structure containing a metal liner with an additional elastic layer according to the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Conventional fiber-wound structures containing metal linings such as Figure 1 As shown in the figure, it includes an inner metal layer and an outer fiber winding structure. Since the metal lining is very thin, compressive stress is generated inside the metal lining under the action of fiber tension during the winding process. As the winding tension increases, the weakening effect of the stress stiffness matrix increases. When a certain load is reached, its weakening effect exceeds the inherent stiffness of the metal lining, and the metal lining undergoes buckling failure.

[0027] In order to alleviate the deformation and buckling of metal, the present invention proposes a fiber-wound shell with a metal liner and an additional elastic layer, such as Figure 2 As shown, it includes a metal lining, an elastic layer, and a fiber shell structure; the elastic layer is located between the metal lining and the fiber shell structure, and smoothly covers the overlapping position of the shell barrel section and the head; the inner surface of the elastic layer is bonded to the outer surface of the metal lining, and the outer surface of the elastic layer is bonded to the inner surface of the fiber shell structure; the thickness of the elastic layer is uniform, which is 5% to 10% of the total thickness of the metal lining + fiber shell structure.

[0028] Preferably, the material of the elastic layer can be selected from EPDM rubber material and nitrile rubber material.

[0029] There are two methods for preparing the elastic layer. One is to mold it into a larger rectangular sheet, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a hand-pasting process; the other is to mold it into a narrow strip, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a winding process.

[0030] Accordingly, the present invention proposes a design method for a filament-wound shell containing a metal liner for alleviating deformation buckling, comprising the following steps:

[0031] (1) First, the manufacturing process of the metal liner is completed according to the conventional metal liner forming process;

[0032] (2) Grinding the outer surface of the metal lining (without reducing the thickness of the metal lining) to increase the roughness of the outer surface of the metal lining;

[0033] (3) Making an elastic layer of equal thickness, the elastic layer material is EPDM rubber material, and the thickness of the elastic layer is 5% to 10% of the total thickness of the metal liner + fiber shell structure;

[0034] (4) Apply glue on the outer surface of the metal lining to ensure that the elastic layer and the metal lining are firmly bonded to prevent debonding. After applying glue, evenly paste an elastic layer of equal thickness on the outer surface of the metal lining. During the process of pasting the elastic layer, ensure that the elastic layer completely covers the metal lining and has a uniform thickness, especially at the overlap position of the shell section and the head. Ensure that the elastic layer at this position has a smooth transition and no warping;

[0035] (5) applying glue on the outer surface of the elastic layer, and after the application of glue, performing fiber winding on the outer surface of the elastic layer, the fiber winding process is consistent with the process of the original fiber winding shell containing a metal liner;

[0036] (6) After the shell is wound, the shell is placed in a curing furnace for curing. During the curing process, the elastic layer completes the vulcanization process along with the curing furnace. After the curing is completed, the manufacturing process of the entire shell is completed and other subsequent processes can be carried out.

[0037] Among them, the preparation process of the elastic layer in step (3) includes: two schemes, one is to mold it into a larger rectangular sheet, and the elastic layer corresponding to this scheme is pasted on the outer surface of the metal lining by a hand-pasting process; the other is to mold it into a narrow strip, and the elastic layer corresponding to this scheme is pasted on the outer surface of the metal lining by a winding process.

[0038] The curing temperature during the shell curing process in step (6) should cover the vulcanization temperature of the elastic layer.

[0039] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0040] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A filament-wound shell containing a metal liner for alleviating metal deformation and buckling, characterized in that: It includes a metal lining, an elastic layer, and a fiber shell structure; the inner surface of the elastic layer is bonded to the outer surface of the metal lining, and the outer surface of the elastic layer is bonded to the inner surface of the fiber shell structure; the thickness of the elastic layer is uniform, which is 5% to 10% of the total thickness of the metal lining + fiber shell structure, and smoothly covers the overlapping position of the shell barrel section and the head.

2. The filament-wound shell containing a metal liner for alleviating metal deformation and buckling according to claim 1, characterized in that: The material of the elastic layer is selected from EPDM rubber material and nitrile rubber material.

3. The filament-wound shell containing a metal liner for alleviating metal deformation and buckling according to claim 1, characterized in that: The preparation of the elastic layer includes the following two methods: One is molded into a rectangular sheet, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a hand-pasting process; the other is molded into a narrow strip, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a winding process.

4. A method for designing a filament-wound shell containing a metal liner to alleviate metal deformation and buckling, characterized in that: The following steps are involved: Complete the manufacturing process of metal lining; Grinding the outer surface of the metal lining to increase the roughness of the outer surface of the metal lining; Making an elastic layer of equal thickness, the thickness of the elastic layer is 5% to 10% of the total thickness of the metal lining + fiber shell structure; After brushing glue on the outer surface of the metal lining, evenly paste the elastic layer of equal thickness. During the pasting process of the elastic layer, ensure that the elastic layer completely covers the metal lining and ensure that the elastic layer at the overlap position of the shell section and the head is smooth and has no warping edges; Fiber winding is performed after applying glue on the outer surface of the elastic layer; After the shell is wound, the entire shell is placed in a curing oven for curing.

5. The method for designing a filament-wound shell containing a metal liner for alleviating metal deformation and buckling according to claim 4, characterized in that: The material of the elastic layer is selected from EPDM rubber material and nitrile rubber material.

6. The method for designing a filament-wound shell containing a metal liner for alleviating metal deformation and buckling according to claim 4, characterized in that: The preparation of the elastic layer includes the following two methods: One is molded into a rectangular sheet, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a hand-pasting process; the other is molded into a narrow strip, and the corresponding elastic layer is pasted on the outer surface of the metal lining by a winding process.

7. The method for designing a filament-wound shell containing a metal liner for alleviating metal deformation and buckling according to claim 4, characterized in that: The curing temperature covers the vulcanization temperature of the elastic layer, and during the curing process, the elastic layer completes the vulcanization process along with the curing furnace.

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