Orthogonal upright carbon fiber reinforced cylindrical shell structure and processing method thereof

Abstract

The invention relates to an orthogonal upright carbon fiber reinforced cylindrical shell structure and a processing method thereof.The orthogonal upright carbon fiber reinforced cylindrical shell structure comprises a cylindrical shell body and a reinforcing rib structure located on the inner side face of the cylindrical shell body, the cylindrical shell body is made of aluminum alloy and integrally formed through a rotary extrusion process, and the reinforcing rib structure is fixedly connected to the inner side face of the cylindrical shell body; comprising two rows of vertical ribs and transverse ribs located between the two rows of vertical ribs, a plurality of vertical ribs are arranged in each row and distributed in the circumferential direction of the barrel shell body, the transverse ribs are carbon fiber reinforcing ribs and are formed through a carbon fiber prepreg winding technology, and the vertical ribs are made of thermoplastic carbon fiber materials and are machined and formed through a mold pressing technology. On the premise that the bearing performance of the whole structure is guaranteed, the carbon fibers are used for replacing aluminum alloy ribs, and the purpose of overall weight reduction is achieved; and in the aspect of process processing, rotary extrusion, laser welding and fiber winding modes are adopted, the precision in the aspect of rib processing is improved, and the processing method is easy to implement and has high application and popularization values.

Description

Technical Field

[0001] The invention relates to the technical field of manufacturing main load-bearing components of aerospace structures, and in particular to an orthogonal carbon fiber reinforced cylinder shell structure and a processing method thereof. Background Art

[0002] Thin-walled cylindrical shell structures have high specific stiffness and high specific strength. In the field of aerospace, grid-reinforced cylindrical shell structures are widely used as the main connection and load-bearing structure. Under the action of compressive loads, instability is the main form of failure. During the rocket launch process, the thin-walled cylindrical shell structure is subjected to huge axial compressive loads due to overload, and is prone to buckling instability, resulting in structural failure. Therefore, the ultimate bearing capacity of the thin-walled cylindrical shell structure under axial compression conditions is a key assessment indicator in the design process of aerospace structures such as launch vehicles. Under axial compression conditions, the main failure mode of the reinforced cylindrical shell structure is buckling instability, including overall structural instability, local skin instability, local rib instability and material plastic instability.

[0003] In order to meet the strength and stiffness requirements of the components, the skin thickness or rib thickness of the shell is usually increased, which leads to an increase in the weight of the component. At the same time, the existing forming methods of the shell structure are usually casting, extrusion, machining and welding, but each process has certain disadvantages, such as low production precision and easy deformation during processing. In the fields of aviation launch vehicles, satellites, and spacecraft, grid-reinforced shells are often used as connecting components, mainly for bearing. In order to ensure its bearing performance, the skin thickness and reinforcement thickness have to be increased, resulting in a greater price for the metal material grid-reinforced shell to meet the strength and stiffness requirements, thereby increasing the overall structural weight. With existing processing technology, high-precision machining is required in the later stage of forging to ensure the reinforcement accuracy of the product. After extrusion, the rib accuracy is still difficult to guarantee. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide an orthogonal carbon fiber reinforced cylinder shell structure and a processing method thereof.

[0005] The present invention is achieved through the following technical solutions:

[0006] An orthogonal carbon fiber reinforced cylinder shell structure comprises a cylinder shell body and a reinforcing rib structure located on the inner side of the cylinder shell body, wherein the cylinder shell body is made of aluminum alloy and is integrally formed by a rotary extrusion process, wherein the reinforcing rib structure is fixedly connected to the inner side of the cylinder shell body and comprises two rows of vertical ribs and transverse ribs located between the two rows of vertical ribs, wherein each row of the vertical ribs comprises a plurality of ribs distributed along the circumference of the cylinder shell body.

[0007] According to the above technical solution, preferably, the transverse ribs are carbon fiber reinforcement ribs, which are formed by a carbon fiber prepreg winding process.

[0008] According to the above technical solution, preferably, the vertical ribs are made of thermoplastic carbon fiber material and are formed by a molding process.

[0009] According to the above technical solution, preferably, the vertical ribs are fixedly connected to the inner side surface of the cylinder shell body by one or more methods of bonding, riveting, welding, and laser welding.

[0010] According to the above technical solution, preferably, the shell body includes a skin, an upper end frame and a lower end frame located at both ends of the skin, and the reinforcing rib structure is fixedly connected to the surface of the skin.

[0011] According to the above technical solution, preferably, the contact side of the vertical rib with the skin is an arc contact surface, and its inner radius is equal to the radius of the outer surface of the skin.

[0012] According to the above technical solution, preferably, the width of each row of the vertical ribs is unequal, and the two rows of the vertical ribs are arranged in a vertically symmetrical manner.

[0013] The present application also discloses a method for processing an orthogonal carbon fiber reinforced cylindrical shell structure, which is used to process the above-mentioned orthogonal carbon fiber reinforced cylindrical shell structure, and comprises the following steps:

[0014] S1. The shell body is integrally formed by a rotary extrusion process;

[0015] S2. The vertical ribs are fixedly connected one by one to the inner surface of the skin of the shell body, and the positions of the transverse ribs are reserved between the two rows of the vertical ribs, and the spacing is the width of the transverse ribs;

[0016] S3. Using a fiber winding device to wind carbon fiber in the reserved gap between two rows of vertical ribs;

[0017] S4. Place the whole in a high-temperature curing furnace, cool it after curing, and take out the carbon fiber reinforced shell structure to complete the entire process.

[0018] According to the above technical solution, preferably, in step S2, the vertical ribs are fixedly connected to the inner surface of the skin one by one by using a laser welding process, and the laser welding process includes:

[0019] Place the prefabricated vertical reinforcement in the fixture at the top of the fixture;

[0020] The fixing device applies pressure through a cylinder to make the vertical ribs fit tightly against the outer surface of the skin;

[0021] The laser irradiation side of the laser head is located on the inner surface of the skin, and the laser power range of 700w-800w, the laser scanning speed of 10mm / s, and the laser light plate diameter of 5mm are selected as welding process parameters to complete the welding of the vertical ribs and the skin;

[0022] After completing the welding of one set of vertical ribs, the cylinder shell body is rotated by a spacing distance to complete the welding operation of the next set of vertical ribs.

[0023] The beneficial effects of the present invention are:

[0024] The present invention provides an orthogonal carbon fiber reinforced thermoplastic composite grid reinforced cylindrical shell structure, which can utilize carbon fibers to replace aluminum alloy ribs while ensuring the bearing performance of the overall structure, thereby achieving the purpose of overall weight reduction; at the same time, in terms of process processing, unlike the existing traditional processing methods, it adopts rotary extrusion, laser welding and fiber winding, and the accuracy of rib processing is improved. The processing method is easy to implement and has a high application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a main structural schematic diagram of the present invention.

[0026] Figure 2 It is a schematic diagram of the main structure of the barrel shell body of the present invention.

[0027] Figure 3 It is a schematic diagram of the main structure of the reinforcing rib structure part of the present invention.

[0028] Figure 4 It is a schematic diagram of the local structure of the connection between the skin and the reinforcing rib structure of the present invention.

[0029] Figure 5 It is a schematic diagram of the three-dimensional structure of the transverse rib part of the present invention.

[0030] Figure 6 It is a three-dimensional structural schematic diagram of the laser welding process of the present invention.

[0031] In the figure: 1. upper end frame; 2. skin; 3. lower end frame; 4. vertical rib a; 5. transverse rib; 6. vertical rib b; 7. laser welding equipment; 8. robotic arm; 9. laser head; 10. fixing device. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiment. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the invention.

[0033] In the description of the invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the invention.

[0034] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Embodiment 1: As shown in the figure, the present invention discloses an orthogonal carbon fiber reinforced cylinder shell structure, including a cylinder shell body and a reinforcing rib structure located on the inner side of the cylinder shell body. The cylinder shell body is made of aluminum alloy and is integrally formed by a rotary extrusion process. The cylinder shell body includes a skin 2, an upper end frame 1 and a lower end frame 3 located at both ends of the skin 2, and the reinforcing rib structure is fixedly connected to the surface of the skin 2.

[0036] The reinforcing rib structure includes two rows of vertical ribs and transverse ribs 5 located between the two rows of vertical ribs, each row of the vertical ribs includes a plurality of ribs, which are distributed along the circumference of the shell body. The vertical ribs are made of thermoplastic carbon fiber material, formed by molding, and evenly arranged in two rows (i.e., vertical ribs a4 and vertical ribs b6) near the upper end frame 1 and the lower end frame 3 on the shell body. The vertical ribs are fixedly connected to the inner side of the shell body by one or more methods of bonding, riveting, welding, and laser welding. Specifically, in this example, the side where the vertical ribs contact the skin 2 is an arc contact surface, and its inner radius R is equal to the radius R of the outer surface of the skin 2. The vertical ribs a4 and b6 are arranged in a symmetrical manner. In this example, it is preferred but not limited to that three thin vertical ribs are spaced between each thick vertical rib, and they are evenly arranged. When applying actual products, the arrangement can be designed according to the specific stress conditions. In addition, the transverse ribs 5 are carbon fiber reinforcement ribs, which are formed by a carbon fiber prepreg winding process. Specifically, the transverse ribs 5 are formed by a 90° circumferential multi-layer winding method of prepreg, the width of the prepreg is consistent with the width of the transverse ribs 5, and the winding height is consistent with the height of the vertical ribs.

[0037] Embodiment 2: The present application also discloses a method for processing an orthogonal carbon fiber reinforced cylindrical shell structure, which is used to process the above-mentioned orthogonal carbon fiber reinforced cylindrical shell structure, and comprises the following steps:

[0038] S1. The shell body is integrally formed by a rotary extrusion process;

[0039] S2. The vertical ribs are fixedly connected one by one to the inner surface of the skin 2 of the shell body, and the position of the transverse ribs 5 is reserved between the two rows of the vertical ribs, and the spacing is the width of the transverse ribs 5;

[0040] S3. Install the shell body with welded vertical ribs on the fiber winding equipment, and use the fiber winding equipment to wind carbon fiber in the reserved gap between the two rows of vertical ribs. Specifically, in this example, the carbon fiber is T700-grade carbon fiber filament with epoxy resin for 90° circumferential winding, the width of the transverse rib 5 is reserved at 3.5mm, and 1 strand of yarn is selected for winding, with a yarn width of 3.5mm;

[0041] S4. Finally, place the whole in a high-temperature curing furnace. The curing conditions are 80℃ / 2h and 100℃6h. After the curing is completed, stop the furnace and cool it to below 40℃. Take out the reinforced tube to complete the whole process.

[0042] According to the above embodiment, preferably, in step S2, the vertical ribs are fixedly connected one by one to the inner surface of the skin 2 by using a laser welding process, and the laser welding equipment 7 includes a mechanical arm 8, a laser head 9 and a fixing device 10. The laser welding process includes:

[0043] S21. The prefabricated carbon fiber vertical ribs a4 and b6 are placed in the rectangular groove formed by the fixture 10 at the upper portion. The fixture 10 has an automatic locking structure for the vertical ribs and axial lifting and pressurization capabilities (cylinder pressurization);

[0044] S22. The fixing device 10 applies pressure through the cylinder so that the vertical ribs a4 and b6 fit closely with the outer surface of the skin 2;

[0045] S23. The laser irradiation side of the laser head 9 is located on the inner surface of the skin 2, and the laser power range of 700w-800w, the laser scanning speed of 10mm / s, and the laser light plate diameter of 5mm are selected as welding process parameters to complete the welding of the vertical ribs and the skin 2;

[0046] S24. After completing the welding of one set of vertical ribs, the cylinder shell body is rotated by a spacing distance and then the welding operation of the next set of vertical ribs is completed.

[0047] The present invention discloses an orthogonal carbon fiber reinforced thermoplastic composite grid reinforced shell structure and a processing method thereof, wherein the skin and the upper and lower end frames are integrally formed by a rotary extrusion process of an aluminum alloy material, the vertical ribs are carbon fiber reinforcement ribs, formed by a carbon fiber molding process, and the skin is completed by a laser welding process, and the transverse ribs are carbon fiber reinforcement ribs, formed by a carbon fiber prepreg winding process. The carbon fiber grid reinforced shell manufactured by the above processing method reduces the weight of the shell while ensuring the requirements of its strength and rigidity, and reduces the processing difficulty and saves costs.

[0048] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An orthogonal carbon fiber reinforced shell structure, characterized in that: It includes a shell body and a reinforcing rib structure located on the inner side of the shell body. The shell body is made of aluminum alloy and is integrally formed by a rotary extrusion process. The reinforcing rib structure is fixedly connected to the inner side surface of the cylindrical shell body, and comprises two rows of vertical ribs and transverse ribs (5) located between the two rows of vertical ribs. Each row of the vertical ribs comprises a plurality of ribs distributed along the circumference of the cylindrical shell body.

2. According to claim 1, an orthogonal carbon fiber reinforced cylindrical shell structure is characterized in that: The transverse ribs (5) are carbon fiber reinforcement ribs, which are formed by a carbon fiber prepreg winding process.

3. The orthogonal carbon fiber reinforced shell structure according to claim 2, characterized in that: The vertical ribs are made of thermoplastic carbon fiber material and are formed by a molding process.

4. The orthogonal carbon fiber reinforced shell structure according to claim 3, characterized in that: The vertical ribs are fixedly connected to the inner side surface of the cylinder shell body by one or more methods of bonding, riveting, welding, and laser welding.

5. The orthogonal carbon fiber reinforced shell structure according to any one of claims 1 to 4, characterized in that: The shell body comprises a skin (2), an upper end frame (1) and a lower end frame (3) located at two ends of the skin (2), and the reinforcing rib structure is fixedly connected to the surface of the skin (2).

6. The orthogonal carbon fiber reinforced cylindrical shell structure according to claim 5, characterized in that: The contact side of the vertical rib with the skin (2) is an arc contact surface, the inner radius of which is equal to the radius of the outer surface of the skin (2).

7. The orthogonal carbon fiber reinforced cylindrical shell structure according to claim 1, characterized in that: The widths of the vertical ribs in each row are not equal.

8. The orthogonal carbon fiber reinforced cylindrical shell structure according to claim 7, characterized in that: The two rows of vertical ribs are arranged in a vertically symmetrical manner.

9. A method for processing an orthogonal carbon fiber reinforced cylindrical shell structure, used for processing an orthogonal carbon fiber reinforced cylindrical shell structure as claimed in claim 5, characterized in that: The steps include: S1. The shell body is integrally formed by a rotary extrusion process; S2. The vertical ribs are fixedly connected one by one to the inner surface of the skin (2) of the shell body, and positions for transverse ribs (5) are reserved between the two rows of vertical ribs, with the spacing being the width of the transverse ribs (5); S3. Using a fiber winding device to wind carbon fiber in the reserved gap between two rows of vertical ribs; S4. Place the whole in a curing furnace, cool it after curing, and take out the carbon fiber reinforced shell structure to complete the entire process.

10. The method for processing an orthogonal carbon fiber reinforced cylindrical shell structure according to claim 9, characterized in that: In step S2, the vertical ribs are fixedly connected one by one to the inner surface of the skin (2) by using a laser welding process, and the laser welding process includes: Placing the prefabricated vertical reinforcement in a fixture at the upper portion of the fixing device (10); The fixing device (10) applies pressure through a cylinder so that the vertical ribs are closely fitted to the outer surface of the skin (2); The laser irradiation side of the laser head (9) is located on the inner surface of the skin (2), and the laser power usage range of 700W-800W, the laser scanning speed of 10mm / s, and the laser light plate diameter of 5mm are selected as welding process parameters to complete the welding of the vertical ribs and the skin (2); After completing the welding of one set of vertical ribs, the cylinder shell body is rotated by a spacing distance to complete the welding operation of the next set of vertical ribs.

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