Large-span continuous reinforced integral wall plate type sealed cabin shell structure

Abstract

A large-span continuous reinforced integral wall plate type sealed cabin shell structure belongs to the technical field of spacecraft sealed cabin structures, is used for providing high bearing efficiency of a whole cabin and meeting the requirement of extreme light weight, and comprises a frame and a wall plate which are welded by adopting a friction stir welding process; the wall plate comprises ribs and skin which are integrally formed. The ribs are of a continuous structure and comprise main ribs and auxiliary ribs. The main reinforcements play a main bearing role and can improve the load transmission efficiency; the auxiliary ribs are used for improving local stability; the main reinforcements comprise longitudinal main reinforcements, annular main reinforcements and inclined main reinforcements, the longitudinal main reinforcements and the annular main reinforcements are continuous in the whole cabin and are distributed according to the load layout condition, the inclined main reinforcements are arranged on column sections of the whole cabin and are distributed according to the load layout, the auxiliary reinforcements are uniformly distributed among the main reinforcements of the whole cabin, and the whole cabin is continuous.

Description

Technical Field

[0001] The invention relates to a large-span continuously reinforced integral wall plate type sealed cabin shell structure, belonging to the technical field of spacecraft sealed cabin structures. Background Art

[0002] The sealed cabin is an important section of the manned lunar lander. It is the section where astronauts can land on the moon, work and live on the moon, and take off and return from the moon. The sealed cabin structure must have both load-bearing and sealing functions. Compared with other manned spacecraft in low-Earth orbit such as space stations, the manned lunar lander has a longer flight distance and needs to realize functions such as taking off from the moon, so the platform has a stronger demand for lightweighting.

[0003] Wall panel sealed cabins are widely used in manned spacecraft because of their advantages such as high structural efficiency, high reliability and strong adaptability. Traditional wall panel sealed cabins weld wall panel parts, frame parts and the like into one body by welding, wherein the wall panel is a skin reinforced structure, and the wall panel reinforcement ribs are upright and orthogonal reinforcement ribs. The above traditional sealed cabin structure has the following problems.

[0004] (1) The stiffeners are not continuous throughout the cabin. There are no stiffeners on the connecting frame. The stiffeners of the wall panels are cut off in the weld area. The stiffeners are not continuous in the longitudinal and circumferential directions, resulting in indirect load transfer and low structural load-bearing efficiency.

[0005] (2) The cabin skin is relatively thick, the wall plate reinforcement is relatively high and thick, the rib parameters are consistent throughout the cabin, all ribs are of equal height and width, and have the same parameters. It is impossible to adjust the rib parameters according to the load and layout, resulting in a low degree of lightweighting;

[0006] (3) Due to process limitations, the wall panel parameters cannot be further thinned, nor can the parameters be optimized, which limits the need to further optimize the weight of the manned lunar capsule.

[0007] (4) The reinforcing ribs are all orthogonal and their orientation and layout are not changed due to large openings in the side walls or the installation of large loads. Therefore, the load transfer efficiency is not high and does not meet the lightweight requirements of the lunar lander.

[0008] Therefore, the specific issues that need to be addressed are as follows:

[0009] (1) The lunar module of the Apollo Program exited the cabin through the square hatch at the front of the cylindrical cabin. In order to ensure the convenience of exiting the cabin and the safety of the astronauts, it is better to exit the cabin from the side of the cabin. A square exit opening needs to be set on the side wall of the cabin. The opening on the side wall of the cabin will greatly weaken the overall rigidity of the sealed cabin. At the same time, the surrounding structure of the door frame needs to be integrated with the cabin door. It is required to ensure the overall rigidity of the cabin and match the rigidity of the cabin and door to ensure the sealing performance.

[0010] (2) The sealed cabin is connected to the propulsion cabin through a pyrotechnic lock. The local load at a single point of the pyrotechnic lock connection is large, reaching more than 10 tons. Currently, there is no efficient connection method for the sealed cabin.

[0011] (3) The lunar module of the Apollo Program consisted of an ascent stage and a descent stage. Its landing legs were installed on the non-sealed descent stage to achieve lunar landing. In order to make the configuration more compact, it was considered not to set up an ascent stage and a descent stage. The landing legs were directly installed on the sealed cabin. The landing impact load of the landing legs was as high as 6 tons. How to install the landing legs on a thin-walled sealed cabin and withstand the large landing impact load was a difficult problem that needed to be solved.

[0012] (4) For the first time, the sealed cabin was equipped with an ultra-large mass tank, weighing 6 tons. The payload during the launch phase reached 60 tons. How the sealed cabin could connect the tank and withstand the huge tank load was a difficult problem that needed to be solved. Summary of the invention

[0013] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a large-span continuously reinforced integral wall plate sealed cabin shell structure with high cabin load-bearing efficiency and extreme lightness.

[0014] The purpose of the present invention is achieved through the following technical solutions:

[0015] In a first aspect, the present invention provides a large-span continuous reinforced integral wall plate sealed cabin shell structure, comprising a front cone section, a first column section, a second column section, and a rear cone section, wherein a connecting frame is provided between the front cone section and the first column section, between the first column section and the second column section, and between the second column section and the rear cone section;

[0016] The first column section and the second column section are both panel structures, each of which is welded from multiple panel parts; the front cone section is integrally formed using a spinning process, and the rear cone section uses an integral forging ring without welding seams; all components and the connecting frame are welded using a stir friction welding process to form the entire cabin;

[0017] The whole cabin is provided with reinforcements, which are continuous structures, including main reinforcements and auxiliary reinforcements. The main reinforcements play the main load-bearing role and can improve the load transfer efficiency; the auxiliary reinforcements are used to improve local stability.

[0018] The main reinforcement includes longitudinal main reinforcement, circumferential main reinforcement and oblique main reinforcement. The longitudinal main reinforcement and circumferential main reinforcement are continuous in the whole cabin and are distributed according to the load layout. The oblique main reinforcement is set in the column section of the whole cabin and is distributed according to the load layout. The auxiliary reinforcement is evenly distributed between the main reinforcements and is continuous in the whole cabin.

[0019] In combination with the first aspect, preferably, the connecting frame is an integral circular structure, the outer wall of the connecting frame has longitudinal reinforcement ribs, the cross-section of the connecting frame is determined based on the internal pressure load, welds are set at both ends of the connecting frame, a stiffness enhancing flange is set on the inner side of the connecting frame, and a lightening groove is set on the flange.

[0020] In a second aspect, the present invention provides a large-span continuously reinforced integral wall plate type sealed cabin shell structure, comprising a frame and a wall plate, wherein the frame and the wall plate are welded by a stir friction welding process;

[0021] The wall panel includes ribs and skin, which are formed in one piece. The ribs are continuous structures, including main ribs and auxiliary ribs. The main ribs play the main bearing role and can improve the load transfer efficiency. The auxiliary ribs are used to improve local stability.

[0022] The main reinforcement includes longitudinal main reinforcement, circumferential main reinforcement and oblique main reinforcement. The longitudinal main reinforcement and circumferential main reinforcement are continuous in the whole cabin and are distributed according to the load layout. The oblique main reinforcement is set in the column section of the whole cabin and is distributed according to the load layout. The auxiliary reinforcement is evenly distributed among the main reinforcements of the whole cabin and is continuous in the whole cabin.

[0023] In combination with the first aspect or the second aspect, preferably, the distribution angle of the longitudinal main reinforcement in the circumferential direction of the entire cabin is adjusted according to the cabin configuration size and load layout, the distribution position of the annular main reinforcement is adjusted according to the cabin configuration size and load layout, and the distribution position and angle of the oblique main reinforcement are adjusted according to the cabin configuration size and load layout.

[0024] In combination with the first aspect or the second aspect, preferably, the main reinforcement is determined by the following optimization process:

[0025] Firstly, a finite element model of the sealed cabin structure is established. According to the load conditions of the lunar lander, the main reinforcement is topologically optimized to determine the layout position and configuration of the main reinforcement. The topological optimization is based on the constraints of meeting the strength and stiffness requirements and the goal of minimizing the structural weight. Then, the machinable model is reconstructed according to the topological optimization results. Then, the main reinforcement thickness in different areas and the overall reinforcement height are used as optimization variables for parameter optimization. The parameter optimization is based on the constraints of the minimum structural instability coefficient ≥ 2 and the goal of minimizing the weight. Finally, the model is reconstructed for strength and stiffness verification.

[0026] In combination with the first aspect or the second aspect, preferably, the auxiliary reinforcement is determined by the following optimization process: taking the minimum instability coefficient of the local structure ≥ 2 as a constraint and minimizing the weight as a goal, the auxiliary reinforcement parameters are optimized.

[0027] Combined with the second aspect, preferably, the wall panel rib processing process is: the non-welding area completes the rib processing in the part state, the welding area is not processed before welding, the welding area is reserved as a uniform thick material of a certain thickness, and after welding is completed, the ribs in this area are milled.

[0028] In combination with the first aspect or the second aspect, preferably, a hatch door that can be opened and closed inwards and outwards is provided on the side of the sealed cabin shell structure, a reinforcing beam is screwed at the hatch opening, annular load expansion reinforcement ribs are partially provided at the hatch opening, and the local skin is not specially thickened.

[0029] In combination with the first aspect or the second aspect, preferably, the two-cabin connecting corner boxes are glued and screwed on the mating surface of the sealed cabin shell structure. In order to efficiently diffuse the load, the bonding surface between the two-cabin connecting corner boxes and the cabin body is designed to be semicircular, and a shear cone sleeve is nested in the connecting corner box to bear the shear load of the two cabins.

[0030] In combination with the first aspect or the second aspect, preferably, landing legs are installed below the sealed cabin shell structure, with a total of four landing legs, which are evenly arranged in the circumferential direction, and each landing leg includes a main leg and two auxiliary legs; the main legs and the auxiliary legs are connected to the cabin body through connecting corner boxes, and the connecting corner boxes corresponding to the main legs are glued and screwed to the rear connecting frame of the sealed cabin shell structure, and the high-strength rear connecting frame is used for load bearing. At the same time, the connecting corner boxes corresponding to the main legs are connected to the sealed cabin shell structure by surface connection, which is conducive to bearing shear loads; the two auxiliary legs are connected to the connecting corner boxes of the two cabins.

[0031] In combination with the first aspect or the second aspect, preferably, an inverted cone skirt structure is provided on the inner side wall of the sealed cabin, and the skirt-shaped skin is obliquely pulled onto the sealed cabin shell to achieve connection and bearing of the tank.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) Improved load-bearing efficiency: Compared with traditional wall-plate sealed cabins, all the reinforcing ribs of the integral wall-plate sealed cabin, including longitudinal ribs, annular ribs, and diagonal ribs, are continuous structures. The ribs are not disconnected in the annular weld and longitudinal weld areas, so the force transmission is direct and continuous, and the load transfer efficiency is improved;

[0034] (2) Reduced weight of sealed cabin structure: Different from the orthogonal reinforcement ribs of traditional siding sealed cabins, the siding ribs of integral siding sealed cabins are multi-level, including main ribs and auxiliary ribs. The main ribs play the main load-bearing role and have high load-bearing efficiency. The main ribs are composed of longitudinal main ribs, annular main ribs and large-span integral oblique main ribs. The longitudinal main ribs, annular main ribs and oblique ribs work together, with high load transfer efficiency and good overall structural stability. The auxiliary ribs are composed of longitudinal auxiliary ribs, annular auxiliary ribs and oblique auxiliary ribs, which are used to improve local stability. The multi-level continuous reinforcement configuration has good stability and good buckling resistance. It can also suppress local instability, has strong load-bearing capacity and a high degree of structural lightweight.

[0035] (3) Flexible design: Unlike the traditional wall-plate sealed cabin with all the same parameters of the orthogonal reinforcement ribs, the main and auxiliary reinforcements of the integral wall-plate sealed cabin have different functions. The parameters can be optimized according to the size of the sealed cabin, the load size, and the load layout. The main reinforcement and auxiliary reinforcement are designed with different parameters. In addition, the direction of the reinforcement can be changed according to the load requirements, which greatly reduces the weight of the structure. The design can be changed according to needs, with flexible design and higher degree of lightweight.

[0036] (4) Adopting new technology to improve structural performance: For the first time, stir friction welding with high welding coefficient and excellent welding performance is used on manned spacecraft to achieve welding of medium-thickness cabin structure, thereby realizing continuous reinforcement of the cabin structure; the raw material of the front spherical cone is integrally formed by spinning process, and the raw material of the rear cone structure is integrally forged ring, without welding seams, which improves structural efficiency, enhances structural rigidity and simplifies the processing technology.

[0037] (5) Efficient reinforcement of hatch openings: Reinforcement beams are directly bolted to the hatch openings instead of local thickening. There is no need to design complex cross-section reinforcement frames for the wall panels, the raw materials do not need to be thickened a lot, and the processing technology is simplified. Annular load expansion reinforcement ribs are designed locally at the hatch openings, and local skin does not need to be specially thickened, which has high structural efficiency and lightweight.

[0038] (6) The connection of the two cabins’ pyrotechnic locks is achieved by gluing and screwing the two cabins’ connecting corner boxes on the cabin hull butt surfaces. The semicircular corner boxes are glued to the side walls to efficiently diffuse the interface loads. Shear cone sleeves are embedded in the corner boxes to bear the shear loads of the two cabins.

[0039] (7) The main leg corner box of the landing leg is glued and screwed to the rear connection frame, and the high-strength rear connection frame is used for load bearing. The two auxiliary legs are connected to the two-cabin connection corner boxes, and the two-cabin connection corner boxes and cabin reinforcement areas are reused, thereby improving the structural efficiency.

[0040] (8) The side wall is designed with an inverted tapered skirt structure, and the skin is diagonally pulled to the side wall to achieve the connection and load-bearing of the tank. This connection form reduces the bending moment of the tank load acting on the side wall, effectively solving the load-bearing problem.

[0041] (9) The product of the present invention has been verified by ground tests and has passed the identification level test. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the structural composition of the large-span continuously reinforced integral wall plate type sealed cabin shell of the present invention;

[0043] Figure 2 It is a schematic diagram of the sealed cabin shell structure (square exit opening angle);

[0044] Figure 3 It is a schematic diagram of the main reinforcement of the sealed cabin shell structure; Figure 3 a is the two-dimensional unfolded diagram of the main reinforcement, Figure 3 b is a three-dimensional schematic diagram of the main reinforcement;

[0045] Figure 4 It is a schematic diagram of auxiliary reinforcement of the sealed cabin shell structure; Figure 4 a is the two-dimensional unfolded view of the auxiliary reinforcement. Figure 4 b is a three-dimensional schematic diagram of the auxiliary reinforcement;

[0046] Figure 5 It is a schematic diagram of the front ball cone of the sealed cabin shell structure;

[0047] Figure 6 It is a front spherical cone cross-section of the sealed cabin shell structure;

[0048] Figure 7 It is a schematic diagram of the column section wall panel of the sealed cabin shell structure;

[0049] Figure 8 It is a cross-sectional view of the column section wall plate of the sealed cabin shell structure;

[0050] Fig. 9 It is a schematic diagram of the rear cone section of the sealed cabin shell structure;

[0051] Fig.10 1. It is a schematic diagram of the hatch opening structure of the sealed cabin shell;

[0052] Fig.11 (a) is a schematic diagram of the composition of the I-beam structure for the side reinforcement of the sealed hatch;

[0053] Fig.11 (b) is a schematic diagram of the overall structure of the I-beam reinforced by the sealed hatch side;

[0054] Fig.12 This is a schematic diagram of the connection structure of the two-cabin pyrotechnic locks;

[0055] Fig.13 This is a schematic diagram of the connection between the two cabins;

[0056] Fig.14 This is a schematic diagram of the connection between the landing legs and the cabin;

[0057] Fig.15 It is the landing leg and main leg connection structure;

[0058] Fig.16 It is the landing leg and auxiliary leg connection structure;

[0059] Fig.17 It is a schematic diagram of the tank connection structure. DETAILED DESCRIPTION

[0060] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0061] A large-span continuously reinforced integral wall plate sealed cabin shell structure, which includes a front cone section 2, a first column section 4, a second column section 6, and a rear cone section 8, as distinguished from top to bottom by the structural appearance. Connecting frames are provided between the front cone section 2 and the first column section 4, between the first column section 4 and the second column section 6, and between the second column section 6 and the rear cone section 8. All components are welded as a whole to form a sealed cabin shell structure.

[0062] A large-span continuous reinforced integral wall plate sealed cabin shell structure, which can also be divided into frame and wall plate according to the form of component parts. The main materials of frame and wall plate are 5B70 aluminum alloy. In order to meet the lightweight requirements, the wall plate includes ribs and ultra-thin skin, the thickness of the ultra-thin skin is only 1.2mm, and the total height of the sealed cabin shell wall plate reinforcement is only 15mm.

[0063] The wall plate reinforcements of the sealed cabin shell structure are all continuous structures, and the reinforcements in the circumferential weld and longitudinal weld areas are not disconnected, so the force transmission is direct and continuous, and the load transmission efficiency is high.

[0064] In order to improve the load transfer efficiency, the wall panel reinforcement is in a multi-level form (divided into two levels), including main reinforcement and auxiliary reinforcement. The main reinforcement includes longitudinal main reinforcement, circumferential main reinforcement and oblique main reinforcement. The longitudinal main reinforcement and circumferential main reinforcement are continuous in the whole cabin and are distributed according to the load layout. The oblique main reinforcement is set in the first column section 4 and the second column section 6. The auxiliary reinforcement is evenly distributed between the main reinforcements and is continuous in the whole cabin.

[0065] The main reinforcement includes longitudinal main reinforcement, annular main reinforcement and oblique main reinforcement, which are continuous in the whole cabin. The longitudinal main reinforcement, annular main reinforcement and oblique main reinforcement work together, with high load transfer efficiency and good overall structural stability. The continuous oblique main reinforcement has greatly improved the load-bearing efficiency compared to the traditional pure reinforcement, and the angle of the oblique main reinforcement can be adjusted according to the cabin configuration size and the main load of the cabin.

[0066] The wall reinforcement and main reinforcement optimization process of the sealed cabin shell structure are as follows: first, a finite element model of the sealed cabin structure is established, and according to the load conditions of the lunar lander, the main reinforcement of the wall reinforcement is topologically optimized to determine the layout position and configuration of the reinforcement. The topological optimization is based on the constraints of strength and stiffness meeting the requirements and the goal of minimum structural weight; the second step is to reconstruct the processable model according to the topological optimization results; the third step is to use the reinforcement thickness in different regions and the overall reinforcement height as optimization variables for parameter optimization. The parameter optimization is based on the constraint of minimum structural instability coefficient ≥2 and the goal of minimum weight; the fourth step is to check the strength and stiffness after the model is reconstructed. The auxiliary reinforcement optimization process is as follows: the auxiliary reinforcement parameters are optimized with the constraint of minimum local structural instability coefficient ≥2 and the goal of minimum weight.

[0067] The sealed cabin shell structure adopts a new process to improve the structural performance: for the first time, stir friction welding with a high welding coefficient and excellent welding performance is used on a manned spacecraft to achieve the welding of medium-thickness cabin structures, thereby achieving continuous reinforcement of thin-walled cabin structures. Specifically: the front spherical cone raw material of the front cone section 2 is integrally formed using a spinning process, and the raw material of the rear cone section 8 uses an integral forging ring without welding seams, thereby improving structural efficiency, enhancing structural rigidity, and simplifying processing technology. The connection frames and wall panels in other positions are welded using a stir friction welding process.

[0068] In order to ensure the continuity of the wall panel reinforcement, the wall panel reinforcement processing process is as follows: the non-weld area completes the reinforcement processing in the part state, the welding area is not processed before welding, and the welding area is reserved as a 20mm thick uniform thick material. After welding is completed, the reinforcement in this area is milled. The VPPA welding thickness used in traditional manned sealed cabins is 3 to 10mm, which cannot meet the requirements, so stir friction welding with a larger welding thickness range is used for the first time on manned sealed cabins.

[0069] The front cone section 2 is an integral wall panel structure of a dome configuration, which is integrally formed without weld joints. The raw materials adopt an integral spinning forming process, which reduces the welding links between the wall panels, optimizes the manufacturing process, and increases the shell rigidity. The first column section 4 and the second column section 6 are wall panel structures, which are welded from four wall panel parts respectively. The sealed cabin rear cone section 8 is integrally formed, and the raw materials adopt an integral ring-binding process, which reduces two ring welds and multiple longitudinal welds, optimizes the manufacturing process, and increases the shell rigidity.

[0070] The large-span continuously reinforced integral wall panel sealed cabin shell structure is designed with an exit hatch that can be opened and closed inwards and outwards on the side, which serves as a passage for astronauts to enter and exit the lunar surface. The exit hatch opening is directly screwed with reinforcing beams instead of using the traditional local thickening method. The wall panels do not need to be designed with reinforcing frames with complex cross-sections locally, the raw materials do not need to be thickened a lot, and the processing technology is simplified. Annular load expansion reinforcement ribs are designed locally at the hatch opening to improve the local strength and rigidity of the cabin. The local skin does not need to be specially thickened, and the structure has high utilization efficiency and lightweight. The exit hatch is a square hatch with a diameter of 1000mm×1000mm. The side wall of the sealed cabin is designed with an opening of 1000mm×1000mm. The strength and rigidity of the shell structure at the opening are greatly weakened. In order to increase the local rigidity, I-section reinforcement beams are screwed on both sides of the shell to strengthen the shell structure. Fig.11 (a) Fig.11 (b) as shown.

[0071] The connection frames are all annular integral structures, the outer wall of the connection frame has longitudinal reinforcement ribs, the cross section of the connection frame is determined based on the internal pressure load, welding joints are set at both ends of the connection frame, a rigidity enhancement flange is set on the inner side of the connection frame, and a lightening groove is set on the flange. Specifically: the connection frame between the front cone section 2 and the first column section 4 is the front connection frame 3, the connection frame between the first column section 4 and the second column section 6 is the middle frame 5, and the connection frame between the second column section 6 and the rear cone section 8 is the rear connection frame.

[0072] The large-span continuous reinforced integral wall plate sealed cabin shell structure is designed to achieve the connection of the two cabin pyrotechnic locks (such as Fig.12As shown in the figure, the two cabins connecting corner box is glued and screwed on the cabin docking surface (the two cabins connecting corner box and the cabin are glued and screwed) to realize the connection of the two cabins pyrotechnic locks, and the rear end frame of the sealed cabin is the two cabin docking frame; in order to efficiently diffuse the load, the bonding surface of the two cabins connecting corner box and the cabin side wall is designed to be semicircular, and the shear cone sleeve is embedded in the corner box to bear the shear load of the two cabins, as shown in the figure. Fig.13 The main leg connection corner box of the landing leg is glued and screwed to the rear connection frame, and the high-strength rear connection frame is used for load bearing. The landing leg auxiliary leg connection interface is designed on the two-cabin connection corner box, and the auxiliary leg is also connected to the two-cabin connection corner box. The two-cabin connection corner box and the cabin reinforcement area realize structural reuse, which improves the structural efficiency.

[0073] The landing legs are installed below the large-span continuous reinforced integral wall plate sealed cabin shell structure. Fig.14 As shown, there are four landing legs, evenly arranged in the circumferential direction, and each landing leg includes a main leg and two auxiliary legs. The main leg and the auxiliary legs are connected to the cabin body through corner boxes. The main leg corner box is glued and screwed to the rear connection frame, and the high-strength rear connection frame is used for load bearing. At the same time, the main leg connection corner box has a large connection surface with the cabin wall, and is connected to the surrounding skin of the connection frame, which is conducive to bearing shear loads; the two auxiliary legs are connected to the two cabin connection corner boxes. This design can reuse the two cabin connection corner boxes and the cabin body reinforcement area, which improves the structural efficiency. Fig.15 and Fig.16 shown.

[0074] The tank of the lander is limited by the design and process of the common bottom tank. The connecting flange cannot be designed as a conventional integral annular ear piece, but a direct flange. An inverted cone skirt structure is designed on the inner side wall of the sealed cabin, and the skin is diagonally pulled to the side wall. This connection form reduces the bending moment of the tank load on the side wall, and effectively solves the load-bearing problem, such as Fig.17 shown.

[0075] More specific:

[0076] Figure 1 The present invention is a schematic diagram of the composition of a large-span continuous reinforced integral wall plate sealed cabin shell structure. The sealed cabin shell structure consists of a front spherical cone, a column segment, and a rear cone. The connecting frame includes a front frame, a front connecting frame, a middle frame, a rear connecting frame, and a rear frame. The wall plate includes a front cone wall plate, a column segment wall plate 1, a column segment wall plate 2, and a rear cone wall plate. The connecting frame and the wall plate are welded to form the sealed cabin integral shell.

[0077] The total height of the sealed cabin is 3450mm, the front cone height is 500mm, the column section diameter is φ2800mm, and the main material of the shell structure, including the frame and wall panels, is 5B70 aluminum alloy.

[0078] The connecting frame is an integral circular forging ring. The outer wall of the connecting frame has longitudinal reinforcement ribs. The frame cross section is determined according to the internal pressure load. The welding of the connecting frame and the wall plate is as follows: Figure 3 shown.

[0079] The wall reinforcement consists of main reinforcement and auxiliary reinforcement, such as Figure 4 and Figure 5 As shown, the main reinforcement and auxiliary reinforcement are continuous structures at all longitudinal seams and circumferential seams, and are not disconnected in the weld area. In this example, the main reinforcement height of the side wall is 10mm, the main reinforcement width is 3mm, the auxiliary reinforcement skin thickness is 5.7mm, the auxiliary reinforcement width is 2mm, the weld skin thickness is 3mm, the weld height is 50mm, and the grid parameters are approximately between 130mmx130mm and 160mmx150mm.

[0080] The wall plate reinforcement processing is completed in the non-weld area in the part state. The welding area is processed into thick material with the same thickness as the side wall of the cabin before welding. After welding, the reinforcement in this area is completed by milling. The welding form of all longitudinal welds and circumferential welds is stir friction welding. The main reinforcement is composed of longitudinal main reinforcement, circumferential main reinforcement and large-span integral inclined main reinforcement. The inclined main reinforcement in this example is arranged according to the load. The rear cone load is larger, the inclined main reinforcement is arranged densely, and the inclination angle of all main reinforcements is between 30° and 45°.

[0081] The front cone wall plate is a spherical wall plate. Figure 6 and Figure 7 As shown, the front cone wall panel has no welds, the raw material is integrally spun, and the skin thickness is 1.2mm; the column wall panel is as shown Figure 8 and Fig. 9 As shown, column segment wall panels 1 and column segment wall panels 2 are welded from four wall panel parts into an annular wall panel assembly, and the wall panel skin thickness is 1.2 mm; the rear cone wall panel is as shown in FIG. Fig.10 As shown, the rear cone wall plate has no welds and the raw material is an integral forging.

[0082] The hatch opening is locally designed with annular load expansion reinforcement ribs. The hatch opening has an I-shaped section with a thickness of 2mm for the bulkhead, 2mm for the bottom plate, 4.85mm for the vertical plate and 6mm for the top plate. Figure 2 shown.

[0083] Eight pyrotechnic locks and eight spring separation push rods are installed on the separation surface of the two cabins. There are eight pyrotechnic locks evenly distributed around the circumference, with a distribution circle diameter of φ2776mm. In order to achieve the connection of the pyrotechnic locks of the two cabins, a high-strength connection corner box is bonded to the cabin body. As shown in the figure, the corner box material is 7075 high-strength aluminum, and the glue used for bonding with the cabin body and the rear end frame is 420 glue. The two cabins are connected by pyrotechnic locks, a shear cone sleeve is embedded on one side of the lunar module, and a cone is set on one side of the propulsion module. The cabins are shear-resistant through shear cones.

[0084] An inverted cone skirt structure is designed for the inner wall of the sealed cabin. The skirt-shaped skin is obliquely pulled onto the sealed cabin shell. The inverted cone skirt structure is a variable thickness section, and the thickness gradually increases from 10mm to 15mm. A boss is designed on the edge of the skirt, and M12 threaded holes are processed on the boss. There are 92 threaded holes in total for installing the tank.

[0085] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0086] 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.

Claims

1. A large-span continuously reinforced integral wall plate sealed cabin shell structure, characterized in that: It includes a front cone section, a first column section, a second column section, and a rear cone section, and a connecting frame is arranged between the front cone section and the first column section, between the first column section and the second column section, and between the second column section and the rear cone section; The first column section and the second column section are both panel structures, each of which is welded from multiple panel parts; the front cone section is integrally formed using a spinning process, and the rear cone section uses an integral forging ring without welding seams; all components and the connecting frame are welded using a stir friction welding process to form the entire cabin; The whole cabin is provided with reinforcements, which are continuous structures, including main reinforcements and auxiliary reinforcements. The main reinforcements play the main load-bearing role and can improve the load transfer efficiency. Auxiliary reinforcement is used to improve local stability; The main reinforcement includes longitudinal main reinforcement, circumferential main reinforcement and oblique main reinforcement. The longitudinal main reinforcement and circumferential main reinforcement are continuous in the whole cabin and are distributed according to the load layout. The oblique main reinforcement is set in the column section of the whole cabin and is distributed according to the load layout. The auxiliary reinforcement is evenly distributed between the main reinforcements and is continuous in the whole cabin.

2. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 is characterized in that: The connecting frame is an integral circular structure with longitudinal reinforcement ribs on the outer wall. The cross-section of the connecting frame is determined based on the internal pressure load. Welds are arranged at both ends of the connecting frame, a stiffness-enhancing flange is arranged on the inner side of the connecting frame, and a lightening groove is arranged on the flange.

3. A large-span continuously reinforced integral wall plate sealed cabin shell structure, characterized in that: It includes a frame and a wall panel, and the frame and the wall panel are welded by a stir friction welding process; The wall panel includes ribs and skins, which are formed in one piece. The ribs are continuous structures, including main ribs and auxiliary ribs. The main ribs play the main bearing role and can improve the load transfer efficiency. Auxiliary reinforcement is used to improve local stability; The main reinforcement includes longitudinal main reinforcement, circumferential main reinforcement and oblique main reinforcement. The longitudinal main reinforcement and circumferential main reinforcement are continuous in the whole cabin and are distributed according to the load layout. The oblique main reinforcement is set in the column section of the whole cabin and is distributed according to the load layout. The auxiliary reinforcement is evenly distributed among the main reinforcements of the whole cabin and is continuous in the whole cabin.

4. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 or 3, characterized in that: The distribution angle of the longitudinal main reinforcement in the circumferential direction of the entire cabin is adjusted according to the cabin configuration size and load layout, the distribution position of the circumferential main reinforcement is adjusted according to the cabin configuration size and load layout, and the distribution position and angle of the oblique main reinforcement are adjusted according to the cabin configuration size and load layout.

5. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 or 3, characterized in that: The main reinforcement is determined through the following optimization process: Firstly, a finite element model of the sealed cabin structure is established. According to the load conditions of the lunar lander, the main reinforcement is topologically optimized to determine the layout position and configuration of the main reinforcement. The topological optimization is based on the constraints of meeting the strength and stiffness requirements and the goal of minimizing the structural weight. Then, the machinable model is reconstructed according to the topological optimization results. Then, the main reinforcement thickness in different areas and the overall reinforcement height are used as optimization variables for parameter optimization. The parameter optimization is based on the constraints of the minimum structural instability coefficient ≥ 2 and the goal of minimizing the weight. Finally, the model is reconstructed for strength and stiffness verification.

6. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 or 3, characterized in that: The auxiliary reinforcement is determined through the following optimization process: the parameters of the auxiliary reinforcement are optimized with the minimum instability coefficient of the local structure ≥ 2 as the constraint and the minimum weight as the goal.

7. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 3 is characterized in that: The rib processing process of the wall panel is as follows: the rib processing of the non-welding area is completed in the part state, the welding area is not processed before welding, and the welding area is reserved as a uniform thick material of a certain thickness. After welding is completed, the ribs in this area are milled.

8. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 or 3, characterized in that: An exit hatch which can be opened and closed inwards and outwards is provided on the side of the sealed cabin shell structure. A reinforcing beam is screwed at the hatch opening. Annular load expansion reinforcement ribs are provided locally at the hatch opening, and the local skin is not specially thickened.

9. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 or 3, characterized in that: The two-cabin connecting corner boxes are glued and screwed on the butt joint surface of the sealed cabin shell structure. In order to efficiently diffuse the load, the bonding surface between the two-cabin connecting corner boxes and the cabin body is designed to be semicircular, and a shear cone sleeve is nested in the connecting corner box to bear the shear load of the two cabins.

10. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 9, characterized in that: Landing legs are installed below the sealed cabin shell structure, with a total of four landing legs, which are evenly arranged in the circumferential direction. Each landing leg includes a main leg and two auxiliary legs. The main legs and the auxiliary legs are connected to the cabin body through connecting corner boxes. The connecting corner boxes corresponding to the main legs are glued and screwed to the rear connecting frame of the sealed cabin shell structure, and the high-strength rear connecting frame is used for load bearing. At the same time, the connecting corner boxes corresponding to the main legs are connected to the sealed cabin shell structure by surface connection, which is conducive to bearing shear loads. The two auxiliary legs are connected to the connecting corner boxes of the two cabins.

11. The large-span continuously reinforced integral wall plate sealed cabin shell structure according to claim 1 or 3, characterized in that: An inverted cone skirt structure is provided on the inner side wall of the sealed cabin, and the skirt-shaped skin is obliquely pulled onto the sealed cabin shell to achieve connection and bearing of the tank.

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