Buckling-resistant sealed cabin, column segment, column segment main body and design method thereof with extruded ribs and milled ribs

Abstract

The application relates to the field of spacecrafts, in particular to a buckling-resistant sealed cabin with extruded ribs and milled ribs in cooperation and a column section and a column section main body thereof, which comprise: a plurality of wall plates with radii, the plurality of wall plates are circumferentially spliced to form a cylindrical shell; wherein the wall plate comprises: a skin, extruded ribs and milled ribs; the extruded ribs are extruded together with the skin, the extension direction of the extruded ribs is the same as the extrusion direction, and the extruded ribs are located on the outer side of the skin; the milled ribs which cross the extruded ribs are formed on the inner side of the skin by milling. The application breaks through the performance limitation of the equal-section aluminum extruded section sealed cabin and guarantees the buckling resistance of the aluminum extruded section sealed cabin.

Description

Technical Field

[0001] This application relates to the field of spacecraft, and more particularly to a buckling-resistant sealed cabin, column segment, column segment body, and design method thereof, featuring the synergistic effect of extruded and milled ribs. Specifically, it relates to the use of extruded and milled ribs to enhance the buckling resistance of the cabin structure. Background Technology

[0002] With the development of my country's space station and the increasing demands of space missions, the structural research of spacecraft cabins has received increasing attention. The function of a spacecraft cabin is to maintain internal environmental conditions and withstand loads. In the mechanical environment of spacecraft launch, on-orbit operation, and reentry, the spacecraft cabin must withstand launch loads and potential aerodynamic loads, as well as internal pressure loads.

[0003] Stiffened cylindrical shells are widely used in spacecraft sealed cabin structures. Currently, the Tiangong experimental module, the Tianhe core module, and most of the modules of the International Space Station adopt this structural form. As the main load-bearing section of a spacecraft, the thin-walled stiffened cylindrical shell section primarily bears axial compressive inertial loads during launch vehicle flight. For this type of structure, axial instability is the main failure mode. Arranging stiffeners is the main technical means to improve the stability and critical buckling load of the cylindrical shell. Currently, stiffened cylindrical shell configurations include upright orthogonal stiffeners, oblique orthogonal stiffeners, and ISO grid stiffeners, etc. The interlaced stiffeners ensure that the stiffened cylindrical shells have approximately isotropic mechanical properties.

[0004] Buckling typically refers to the abrupt change in the shape of a structure under compressive loads, leading to a significant reduction in its load-bearing capacity. This deformation can occur locally or globally. Spacecraft cabins need to withstand the coupled effects of multiple loads, including axial loads and internal pressure loads, during launch and on-orbit operation. Typical failure modes of cabins include overall buckling, skin buckling, and stiffener buckling. Therefore, designing a cabin structure with good buckling resistance is a prerequisite for the stable operation of spacecraft.

[0005] Due to their lightweight, high strength, and ease of processing, aluminum extrusion profiles are widely used in building materials, transportation vehicles, and other fields. Promoting the application of aluminum extrusion profiles in the load-bearing structures of spacecraft sealed compartments will help accelerate the rapid and high-quality development of the aerospace industry. For a long time, the application of aluminum extrusion profiles in the aerospace field has been limited by the fixed extrusion cross-sectional shape, making it difficult to achieve isotropic mechanical properties similar to traditional structures.

[0006] Therefore, how to overcome the performance limitations of aluminum extruded profile sealing chambers with uniform cross-section and ensure the buckling resistance of aluminum extruded profile sealing chambers is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The purpose of this application is to provide a buckling-resistant sealed chamber, column segment, column segment body and design method of the synergistic effect of extrusion ribs and milling ribs, so as to improve the stability and buckling critical load of the sealed chamber structure.

[0008] To solve the above-mentioned technical problems, this application provides the following technical solution: A column section of a buckling-resistant sealing chamber with synergistic extrusion ribs and milling ribs includes: multiple curved wall panels, which are circumferentially spliced ​​together to form a cylindrical shell; wherein, the wall panels include: skin, extrusion ribs, and milling ribs; the extrusion ribs are extruded together with the skin and the extension direction of the extrusion ribs is the same as the extrusion direction, and the extrusion ribs are located on the outer side of the skin; milling ribs that intersect with the extrusion ribs are formed on the inner side of the skin.

[0009] The column body of the buckling-resistant sealing chamber with the synergistic effect of the extrusion ribs and milling ribs as described above, wherein preferably, the extrusion ribs include: T-shaped extrusion ribs and I-shaped extrusion ribs; the T-shaped extrusion ribs are distributed in the middle of the outer side of the skin and extend perpendicular to the circumferential direction; the I-shaped extrusion ribs are distributed in the edge of the outer side of the skin and extend perpendicular to the circumferential direction, and the positioning and splicing of adjacent two wall panels are achieved by the I-shaped extrusion ribs.

[0010] The main body of the buckling-resistant sealing chamber with the synergistic effect of the extrusion ribs and milling ribs as described above, wherein preferably, the milling ribs include: milling ring ribs, milling oblique ribs, and milling secondary ribs: the milling ring ribs extend circumferentially; the milling oblique ribs extend obliquely and intersect with the milling ring ribs; the milling secondary ribs are distributed around the intersection of the milling oblique ribs and the milling ring ribs as the center point.

[0011] The column body of the buckling-resistant sealing chamber, as described above, features a combination of extrusion ribs and milling ribs. Preferably, multiple T-shaped extrusion ribs are distributed on the outer surface of the skin, with all T-shaped extrusion ribs arranged in equal phases.

[0012] A column segment of a buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs includes: an upper frame, a lower frame, and a column segment body as described in any one of the above; the upper end of the column segment body is fixedly connected to the upper frame, and the lower end of the column segment body is fixedly connected to the lower frame.

[0013] As described above, the column segment of the buckling-resistant sealing chamber, which utilizes the synergistic effect of extruded ribs and milled ribs, preferably includes the following: an E-type connector and an I-type connector; both the upper and lower frames include: an annular base, a welded support, and multiple short ribs; the side of the annular base is fixedly connected to the welded support, the skin is welded to the welded support of the upper frame, and the skin is welded to the welded support of the lower frame; the inner edge of the short rib is fixedly connected to the outer side of the welded support, and the short rib is opposite to the T-type extruded rib and the I-type extruded rib; the E-type connector is located at the joint between the I-type extruded rib and the short rib, and the outer part of the I-type extruded rib and the outer part of the short rib are inserted into the connecting groove of the E-type connector facing inward; the I-type connector is located at the joint between the T-type extruded rib and the short rib, and the lower part of the short rib is inserted into the connecting groove of the I-type connector facing upward, the connecting strip of the I-type connector facing downward is connected to the vertical bar of the T-type extruded rib, and the clamping strip of the I-type connector on the lower side presses against the outer side of the horizontal bar of the T-type extruded rib.

[0014] The column segment of the buckling-resistant sealed chamber, which is described above as having the synergistic effect of extrusion ribs and milling ribs, preferably further includes: in-chamber equipment; and an equipment mounting seat is milled on the inner side of the skin, to which the in-chamber equipment is mounted.

[0015] The column segment of the buckling-resistant sealing chamber, which combines the extrusion ribs and milling ribs as described above, preferably further includes: a circumferential hoop, which is installed on the inner side of the skin.

[0016] A buckling-resistant sealing chamber with the synergistic effect of extrusion ribs and milling ribs includes: an upper conical section and a column section as described in any one of the above, wherein the column section is fixedly connected to the upper conical section through an upper end frame.

[0017] A design method for a column section of a buckling-resistant sealed chamber with synergistic effects of extruded and milled ribs, specifically including the following steps: Step S510, determine the task indicators and structural shape parameters of the column section based on actual task requirements; Step S520, initialize the dimensional parameters of the skin, extruded ribs, and milled ribs using the task indicators and structural shape parameters as constraints, and complete the pre-design of the non-uniform layout of the ribs; Step S530, divide the structural unit cell based on the stiffened wall panel composed of the skin and ribs completed by the pre-design of the non-uniform layout, and establish a unit cell finite element model for the structural unit cell; Step S540, based on... Using the numerical asymptotic homogenization method, the equivalent stiffness coefficient of the structural unit cell is obtained based on the unit cell finite element model; in step S550, the equivalent stiffness coefficient is substituted into the Rayleigh-Ritz formula to analytically obtain the critical linear buckling load of the column segment and determine whether it meets the requirements of the task indicators. If it does, proceed to step S560; otherwise, return to step S520; in step S560, establish a complete finite element numerical model of the column segment to solve for the critical nonlinear buckling load and check whether the critical nonlinear buckling load meets the requirements of the task indicators. If it does, the design is completed; otherwise, return to step S510.

[0018] Compared to the aforementioned background technology, this application meets the stiffness and stability requirements of the sealed cabin during launch and operation through the combined action of extruded and milled ribs in the cabin's wall panels. Furthermore, this application overcomes the problems of strong anisotropy, poor stability, and low critical buckling load in the mechanical properties of traditional aluminum extruded wall panels. By milling away excess material from the extruded profile on the side of the extruded skin without reinforcing ribs, milled ribs are formed, creating near-orthogonal isotropic mechanical properties. This effectively reduces the span of the cabin skin, suppresses local instability of the wall panels, and improves the overall stability of the sealed cabin. Moreover, the use of aluminum extruded wall panels also reduces the cost of the sealed cabin and improves its processing efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 A schematic diagram of the cylindrical section of the sealed chamber; Figure 2 A schematic diagram of the forming process of extruded aluminum profile panels; Figure 3a This is a schematic diagram of one embodiment of the inner side of the wall panel; Figure 3b This is a schematic diagram of another embodiment of the inner side of the wall panel; Figure 4 This is a schematic diagram showing the connection between the wall panel and the upper frame; Figure 5 A flowchart illustrating the design method for a buckling-resistant column segment with synergistic effects of extruded and milled ribs; Figure 6a This is a schematic diagram showing the equal spacing and thickness of milled ring ribs, milled diagonal ribs, and milled secondary ribs in milled ribs; Figure 6b This is a schematic diagram showing the change in the spacing of the milled ring ribs in the milling ribs; Figure 6c This is a schematic diagram illustrating the variation in the thickness of the milling bevel. Figure 6d This is a schematic diagram illustrating the change in the thickness of the secondary milling rib in a milling rib. Figure 7a This is a schematic diagram showing the equal spacing of milled ring ribs in milled ribs; Figure 7b This is a schematic diagram showing the change in the spacing of the milling ring ribs in the milling ribs; Figure 8 A flowchart for solving the equivalent stiffness coefficients of a structural unit cell; Explanation of reference numerals in the attached figures 1-Upper frame; 11-Annular base; 12-Welded support; 13-Short rib; 2-Column segment main body; 21-Wall panel; 211-Skin; 212-T-type extruded rib; 213-I-type extruded rib; 214-Milled rib; 215-Equipment mounting base; 216-E-type connector; 217-I-type connector; 218-Milled diagonal rib; 219-Milled secondary rib; 220-Milled ring rib; 3-Lower end frame; 4-Circumferential hoop; 5-In-cabin equipment. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0022] As described in the background art, the mechanical properties of the sealed cabin wall panel made of aluminum extrusion profiles are highly anisotropic, resulting in poor stability and low critical buckling load. Under the action of axial load during launch, there is a risk of local skin instability and local rib instability.

[0023] To resolve the above issues, please refer to Figure 1This application provides a buckling-resistant sealing chamber with the synergistic effect of extruded ribs and milled ribs, comprising: an upper conical section and a column section (the upper conical section is not shown in the figure); wherein, the column section comprises: an upper end frame 1, a column section body 2 and a lower end frame 3, the upper end of the column section body 2 is fixedly connected to the upper end frame 1 (e.g., by welding, riveting, or bolting), and the lower end of the column section body 2 is fixedly connected to the lower end frame 3 (e.g., by welding, riveting, or bolting), thereby forming the column section; the column section is fixedly connected to the upper conical section through the upper end frame 1, thereby forming a buckling-resistant sealing chamber.

[0024] Please see Figure 1 and Figure 2 The column segment 2 is a cylindrical shell formed by splicing several curved wall panels 21 in a circumferential manner; wherein, the wall panel 21 is made of aluminum extrusion profile as blank, and the wall panel 21 includes: skin 211, T-shaped extrusion rib 212, I-shaped extrusion rib 213 and milling rib 214, and the T-shaped extrusion rib 212 and I-shaped extrusion rib 213 can be collectively referred to as extrusion rib.

[0025] exist Figure 2 In the illustrated embodiment, the T-shaped extrusion rib 212 and the I-shaped extrusion rib 213 are extruded together with the skin 211 using an aluminum extrusion process, and the T-shaped extrusion rib 212 and the I-shaped extrusion rib 213 are located on the outer side of the skin 211. The extension direction of the T-shaped extrusion rib 212 and the I-shaped extrusion rib 213 is the same as the extrusion direction, that is, the extension direction of the T-shaped extrusion rib 212 and the I-shaped extrusion rib 213 is longitudinal, giving the extruded skin 211 a curved shape. The aluminum extrusion process is a manufacturing process that extrudes aluminum alloy materials through a die, extruding a long profile of not less than 20 meters in a single operation, and then dividing the long profile into multiple segments of specific lengths along a direction perpendicular to the extrusion direction according to the size requirements of the spacecraft's sealed cabin. The long extruded profile is formed by continuously extruding aluminum alloy billets through an extrusion die under high temperature and high pressure from an outlet of a specific shape in the die, forming a long strip-shaped metal component with a fixed cross-sectional shape and continuous length.

[0026] T-shaped extrusion ribs 212 are distributed in the middle of the outer side of the skin 211 and extend perpendicularly to the circumferential direction, providing longitudinal stiffness for the column body 2. I-shaped extrusion ribs 213 are distributed at the edge of the outer side of the skin 211 and extend perpendicularly to the circumferential direction, enabling the positioning and splicing of adjacent wall panels 21. In the above description, the extension direction of the T-shaped extrusion ribs 212 and I-shaped extrusion ribs 213 perpendicular to the circumferential direction is the same as the axial direction of the cylindrical shell formed by the circumferential splicing of several wall panels 21.

[0027] Optionally, the vertical members of the T-shaped extrusion rib 212 are connected to the outer surface of the skin 211, and the horizontal members of the T-shaped extrusion rib 212 are parallel to the outer surface of the skin 211. Alternatively, multiple T-shaped extrusion ribs 212 are distributed on the outer surface of the skin 211, with all T-shaped extrusion ribs 212 arranged in equal phase. Still alternatively, two adjacent I-shaped extrusion ribs 213 on two adjacent wall panels 21 can be positioned and spliced ​​using bolts, rivets, etc.

[0028] exist Figure 2 In the embodiment shown, after the extruded long profile is divided into multiple segments of a specific length, the inner surface of the skin 211 is milled by machining to remove excess material from the inner surface of the extruded skin 211, forming milled ribs 214 that intersect with the T-shaped extrusion ribs 212 and I-shaped extrusion ribs 213. That is, the extension direction of the milled ribs 214 is circumferential. The milled ribs 214 provide circumferential stiffness to the column body 2. The milling thickness does not exceed the thickness of the skin 211 to ensure the sealing of the wall panel 21.

[0029] For some specific embodiments, please refer to Figure 3a The milling ribs 214 are arranged in a grid pattern; for example, the milling ribs 214 are machined into nested iso grids. See also... Figure 3b The milled rib 214 extends circumferentially and is orthogonal to the T-shaped extrusion rib 212 and the I-shaped extrusion rib 213. Since the cabin equipment 5 is usually installed on the inner side of the skin 211, the milled rib 214 is milled on the inner side of the skin 211 to form the equipment mounting base 215, according to the type and installation method of the cabin equipment 5, thereby providing reinforcement when the cabin equipment 5 is installed at the equipment mounting base 215.

[0030] Based on the above, such as Figure 6a As shown, the milled ribs 214 arranged in a grid include: milled oblique ribs 218, milled secondary ribs 219, and milled ring ribs 220; wherein, the milled ring ribs 220 extend in a circumferential direction, and the milled ring ribs 220 are orthogonal to the T-shaped extrusion ribs 212 and the I-shaped extrusion ribs 213; the milled oblique ribs 218 extend obliquely, that is, the extension direction of the milled oblique ribs 218 is at a certain angle to the extension direction of the milled ring ribs 220, and the milled oblique ribs 218 intersect with the milled ring ribs 220; the milled secondary ribs 219 are distributed around the intersection of the milled oblique ribs 218 and the milled ring ribs 220 as the center point, and the overall milled ring ribs 220, milled secondary ribs 219, and milled oblique ribs 218 exhibit a periodic distribution.

[0031] Optionally, the spacing between adjacent milled ring ribs 220 is equal, the spacing between adjacent milled inclined ribs 218 is equal, and each milled secondary rib 219 is a regular hexagon. Alternatively, such as... Figure 6bAs shown, the spacing between adjacent milled ring ribs 220 near the upper frame 1 and the lower frame 3 is smaller than the spacing between adjacent milled ring ribs 220 far from the upper frame 1 and the lower frame 3. "Near the upper frame 1 and the lower frame 3" means... Figure 6a and Figure 6b The left and right sides of the middle. Also optional, such as... Figure 6c and Figure 6d As shown, the thickness of the milled inclined rib 218 and the milled secondary rib 219 near the upper frame 1 and the lower frame 3 is greater than the thickness of the milled inclined rib 218 and the milled secondary rib 219 far from the upper frame 1 and the lower frame 3.

[0032] In addition, such as Figure 7a As shown, the circumferentially extending milled rib 214 includes a milled annular rib 220; wherein the milled annular rib 220 extends circumferentially. Optionally, the spacing between adjacent milled annular ribs 220 is equal. Further, Figure 7b As shown, the spacing between adjacent milled ring ribs 220 near the upper frame 1 and the lower frame 3 is smaller than the spacing between adjacent milled ring ribs 220 far from the upper frame 1 and the lower frame 3. "Near the upper frame 1 and the lower frame 3" means... Figure 7a and Figure 7b The left and right sides of the middle.

[0033] This application utilizes the longitudinally extending extruded ribs (T-shaped extruded ribs 212 and I-shaped extruded ribs 213) formed by aluminum extrusion process and the circumferentially extending milled ribs 214 formed by milling process to form approximately isotropic mechanical properties, thereby ensuring the load-bearing capacity and buckling resistance of the wall panel 21, and thus ensuring the load-bearing capacity and buckling resistance of the column segment body 2 and the column segment.

[0034] Based on the above, please refer to Figure 4The wall panel 21 also includes: an E-type connector 216 and an I-type connector 217; the E-type connector 216 has two connecting grooves on its inner side, where "inner side" refers to the direction towards the I-type extrusion rib 213; the I-type connector 217 has an inner and outer extending connecting groove on its upper side, and the lower side of the I-type connector 217 is an inner and outer extending connecting strip, with a pressing strip perpendicular to it on its outer side, where "upper" refers to the direction towards the annular base 11 and "lower" refers to the direction away from the annular base 11; the upper frame 1 and the lower frame 3 can both be made of friction stir solid-phase additive manufacturing, wherein both the upper frame 1 and the lower frame 3 include: an annular base 11, a welded support 12 and multiple short ribs 13; the annular base 11 faces the end face of the column segment body 2 and is fixedly connected to the welded support 12, and the skin 211 of the column segment body 2 is connected to the welded support 12 of the upper frame 1. The main body 2 of the column segment 2 is connected by welding. The skin 211 of the column segment 2 is connected to the welded support 12 of the lower frame 3 by welding. The inner edge of the short rib 13 is fixedly connected to the outer side of the welded support 12. Some of the short ribs 13 are opposite to the T-shaped extrusion rib 212 and some of the short ribs 13 are opposite to the I-shaped extrusion rib 213. The E-type connector 216 is located at the joint between the I-shaped extrusion rib 213 and the short rib 13. The outer part of the I-shaped extrusion rib 213 and the outer part of the short rib 13 are both inserted into the connecting groove of the E-type connector 216 facing inward. The I-type connector 217 is located at the joint between the T-shaped extrusion rib 212 and the short rib 13. The lower part of the short rib 13 is inserted into the connecting groove of the I-type connector 217 facing upward. The connecting strip of the I-type connector 217 facing downward is connected to the vertical bar of the T-shaped extrusion rib 212. The clamping strip of the I-type connector 217 on the lower side is pressed to the outside of the horizontal bar of the T-shaped extrusion rib 212. By using type E connector 216 and type I connector 217, the connection between T-shaped extruded rib 212 and short rib 13, as well as the connection between type I extruded rib 213 and short rib 13, can be achieved, thus ensuring the continuity of the reinforcing ribs and the continuous transmission of load. Of course, other methods can also be used to achieve the connection between T-shaped extruded rib 212 and short rib 13, as well as between type I extruded rib 213 and short rib 13.

[0035] Continue reading Figure 1 The column segment also includes a circumferential hoop 4, which is installed on the inner side of the skin 211, specifically on the surface of the skin 211 where milled ribs 214 are milled. Optionally, the circumferential hoop 4 is installed to the inner side of the skin 211 by adhesive bonding or mechanical connection. Alternatively, the circumferential hoop 4 is located in the middle of the column segment body 2. Also optionally, the circumferential hoop 4 is made of carbon fiber reinforced composite material. Additionally, the column segment also includes: internal equipment 5, which is installed on the equipment mounting base 215, allowing for the installation of different types of internal equipment 5 as needed.

[0036] like Figure 5As shown, this application also provides a design method for the main body of a buckling-resistant sealing chamber with the synergistic effect of extruded ribs and milled ribs, including the following steps: Step S510: Determine the task indicators and structural shape parameters of the column segment based on actual task requirements; Based on the actual task requirements, the task indicators and structural shape parameters of the column segment are determined. The task indicators include necessary design parameters such as minimum linear buckling load, minimum nonlinear buckling load, structural mass, and structural stiffness. The structural shape parameters include: column segment height. ,radius Necessary geometric parameters, etc.

[0037] Step S520: Using task indicators and structural shape parameters as constraints, initialize the dimensional parameters of skin, extrusion ribs, and milling ribs, and complete the pre-design of non-uniform rib layout. After completing step S510, the task indicators (minimum linear buckling load, minimum nonlinear buckling load, structural mass, and structural stiffness) and structural shape parameters (column height) of the column segment are obtained. ,radius (e.g., geometric parameters), the structural quality in the task indicators is used as the quality indicator constraint for step S520, and the column segment height in the structural shape parameters is used as the constraint. ,radius As the geometric boundary constraint executed in step S520, proceed to step S520.

[0038] Based on engineering experience, initial dimensional parameters for skin thickness, extruded ribs (T-shaped and I-shaped), and milled ribs (milled diagonal ribs 218, milled secondary ribs 219, and milled ring ribs 220) are given, including the thickness and spacing of each rib. The initial dimensional parameters for skin thickness, extruded ribs (T-shaped and I-shaped), and milled ribs (milled diagonal ribs 218, milled secondary ribs 219, and milled ring ribs 220) are candidate initial values ​​obtained through iterative calculations and are not required to directly meet design specifications. Then, a non-uniform layout pre-design is performed for the spacing between each rib (extruded and milled ribs) and the initial dimensional parameters such as the thickness of each rib, as shown below: Continue reading Figure 1 Since the two ends of the column segment 2 are connected to the upper frame 1 and the lower frame 3, the area near the upper and lower ends of the column segment 2 is the main stress-bearing area. Figure 6a It can be seen that the spacing between adjacent milled ring ribs 220 near the top and bottom ends can be adjusted. Specifically, the spacing between adjacent milled ring ribs 220 near the top and bottom ends can be set smaller, while the spacing between adjacent milled ring ribs 220 in the middle can be set larger. The schematic diagram of the adjusted arrangement of milled ring ribs 220 is shown below. Figure 6b As shown.

[0039] The expression for the spacing between adjacent milled ring ribs is as follows: ; Formula 1 in, Representing the The spacing between adjacent milled ring ribs It is the spacing between the first group of adjacent milled ring ribs closest to the top frame. It is the spacing between the last group of adjacent milled ring ribs closest to the bottom frame; This represents the total spacing between the first milled ring rib closest to the top frame and the last milled ring rib closest to the bottom frame; This represents the number of milled ring ribs between adjacent milled ring ribs. For example, if there are 3 milled ring ribs in total, then... =2, if there are a total of 5 milled ring ribs, then =4; This represents the minimum spacing between adjacent milled ring ribs, that is: the spacing between adjacent milled ring ribs closest to the upper / lower frame.

[0040] Continue reading Figure 1 Since the two ends of the column segment 2 are connected to the upper frame 1 and the lower frame 3, the area near the upper and lower ends of the column segment 2 is the main stress-bearing area. Figure 6a It can be seen that the thickness of the milled inclined rib 218 and the milled secondary rib 219 can be adjusted. Specifically, the thickness of the milled inclined rib 218 and the milled secondary rib 219 near the top and bottom ends can be set to be larger, while the thickness of the milled inclined rib 218 and the milled secondary rib 219 in the middle can be set to be smaller. The schematic diagram of the adjusted thickness of the milled inclined rib 218 and the milled secondary rib 219 is shown in the figure. Figure 6c and Figure 6d As shown.

[0041] The expressions for the thickness of milled inclined ribs and milled secondary ribs are as follows: ; Formula 2 ; Formula 3 in, Representing the Thickness of milled inclined ribs / milled secondary ribs; This represents the minimum thickness of the milled rib / secondary rib. This represents the maximum thickness of the milled rib / secondary rib. Representing the Position coefficient for milling inclined ribs / milling secondary ribs; Represents a nonlinear exponent; This represents the total number of sets of milled diagonal ribs / milled secondary ribs.

[0042] Continue reading Figure 1 Since the two ends of the column segment 2 are connected to the upper frame 1 and the lower frame 3, the area near the upper and lower ends of the column segment 2 is the main stress-bearing area. Figure 7a It can be seen that the spacing between adjacent milled ring ribs 220 near the top and bottom ends can be adjusted. Specifically, the spacing between adjacent milled ring ribs 220 near the top and bottom ends can be set smaller, while the spacing between adjacent milled ring ribs 220 in the middle can be set larger. The schematic diagram of the adjusted arrangement of milled ring ribs 220 is shown below. Figure 7b As shown.

[0043] The expression for the spacing between adjacent milled ring ribs is as follows: ; Formula 4 ; Formula 5 in, Representing the The spacing between adjacent milled ring ribs; This represents the minimum spacing between adjacent milled ring ribs, that is: the spacing between adjacent milled ring ribs closest to the upper / lower frame; This represents the maximum spacing between adjacent milled ring ribs, that is: the spacing between adjacent milled ring ribs located at the middle position; This represents the ratio of the maximum spacing to the minimum spacing. Representing the The position coefficient of the spacing between adjacent milled ring ribs; Represents a nonlinear exponent; This represents the number of spacings between adjacent milled ring ribs.

[0044] Step S530: Using the pre-designed skin and stiffeners of the non-uniform layout as the modeling basis, divide the structural unit cells and establish a unit cell finite element model for the structural unit cells. Based on the stiffened wall panel composed of skin and ribs (extruded ribs and milled ribs) pre-designed in step S520, the periodic structure of the stiffened wall panel is divided into structural unit cells. That is, the structural unit cell is a geometric entity cut out from the stiffened wall panel. Each structural unit cell includes: part skin + part extruded ribs + part milled ribs, which is a complete repeating geometric entity. Then, a unit cell finite element model is established for the structural unit cell.

[0045] When dividing the structure into unit cells and establishing the unit cell finite element model, the structural shape parameters (column segment height) given in step S510 are used. ,radius As a mesh constraint, mesh control conditions are executed synchronously to limit the mesh size of the skin element to no greater than the column segment height. And 10% of the diameter to control the mesh size within the skin surface, and ensure that the radial (rib protrusion height direction) of the ribs (extrusion ribs and milling ribs) is divided into at least two layers of mesh to control the number of mesh cells in the rib height direction.

[0046] Step S540: Based on the numerical asymptotic homogenization method, obtain the equivalent stiffness coefficient of the structural unit cell according to the unit cell finite element model; Based on the classical asymptotic homogenization theory, the equivalent stiffness coefficients of the structural unit cell are solved. These equivalent stiffness coefficients include: tensile stiffness coefficients. Coupling stiffness coefficient and bending stiffness coefficient ,like Figure 8 As shown, the specific steps include the following: Sub-step S541: Based on the unit strain field of the structural unit cell set by the asymptotic homogenization theory, construct the nodal displacement field corresponding to the unit strain field; According to the standard mathematical specification of the asymptotic homogenization theory, the in-plane strain field of the structural unit cell is: The unit bending strain field of the structural unit cell is Through the strain-displacement matrix E Constructing the strain field in a unit plane Corresponding nodal displacement field and unit bending strain field Corresponding nodal displacement field ,satisfy: , ; Formula 6 Sub-step S542: Apply nodal displacement field to the unit cell finite element model and solve for nodal support reaction field; The nodal displacement field obtained in substep S541 , The first static analysis was performed on the unit cell finite element model, using the model stiffness matrix. Solving the nodal displacement field Corresponding nodal support reaction field and nodal displacement field Corresponding nodal support reaction field ,satisfy: , ; Formula 7 Sub-step S543: Apply nodal support reaction fields and periodic boundary conditions of the structural unit cells to the unit cell finite element model, and solve for the characteristic displacement field; The nodal support reaction field obtained in sub-step S542 and An external load is applied to the original unit cell finite element model, and periodic boundary conditions of the structural unit cell are applied to the paired boundaries of the unit cell finite element model to conduct a second static analysis. The structural stiffness matrix under the periodic boundary conditions of the structural unit cell is then analyzed. Solve for the nodal support reaction field Corresponding characteristic displacement field and nodal support reaction field Corresponding characteristic displacement field ,satisfy: , ; Formula 8 Sub-step S544: Apply the characteristic displacement field to the unit cell finite element model and solve for the characteristic support reaction field; The characteristic displacement field obtained in sub-step S543 and A third static analysis was performed on the original unit cell finite element model, using the model stiffness matrix. Solving for the characteristic displacement field Corresponding characteristic support reaction field and characteristic displacement field Corresponding characteristic support reaction field ,satisfy: , ; Formula 9 Sub-step S545: Calculate the equivalent stiffness coefficient of the structural unit cell from the nodal displacement field, nodal support reaction field, characteristic displacement field, and characteristic support reaction field. The nodal displacement field obtained from the previous solution and Node support reaction field and Characteristic displacement field and Characteristic support reaction field and Substituting into Formula 10, the tensile stiffness coefficient is calculated. Coupling stiffness coefficient Bending stiffness coefficient ,satisfy: , , ; Formula 10 in, The volume of a structural unit cell; Indicates the first Input working condition for macroscopic deformation of unit number 1, Indicates the first Input condition for macroscopic deformation of unit number.

[0047] Step S550: Substitute the equivalent stiffness coefficient into the Rayleigh-Ritz formula to analyze the critical linear buckling load of the column segment and determine whether it meets the requirements of the task index. If it does, proceed to step S560; otherwise, return to step S520. At the critical buckling state, the total potential energy П of the system caused by buckling displacement is converted into structural strain energy. and external force The total potential energy П is composed of the following components, and its expression is as follows: ; Formula 11 Among them, structural strain energy The expression is as follows: ;Formula 12 in, Represents external force; Represents external torque; subscript , These represent the axial and circumferential directions in the local coordinate system of the thin shell of the column segment, respectively; Represents in-plane strain; Represents in-plane shear strain; Represents curvature; Represents the height of the main column segment. Represents the radius of the main column segment.

[0048] According to classical laminated plate theory, the equilibrium equation of an equivalent continuous plate structure can be expressed as: ; Formula 13 ; Formula 14 , , , , , ; Formula 15 , , ; Formula 16 in, The axial displacement component representing the main body of the column segment; The circumferential displacement component representing the main body of the column segment; The radial displacement component representing the main column segment is substituted into the structural strain energy formula above. Formula 2 yields Formula 17, as follows: ; Formula 17 In addition, external force work The expression is: ; Formula 18 in, Represents the circumferential equivalent critical load, superscript Represents the circumferential direction; Represents circumferential tangential disturbance displacement; Represents the axial critical buckling load, superscript Represents the axial direction; Represents radial normal buckling deflection.

[0049] Based on the deformation characteristics of the buckling modes of thin shells, the displacement components of thin shell buckling under simply supported boundary conditions are expressed using Fourier series: ; Formula 19 ; Formula 20 ; Formula 21 in, , The axial half-wave number, Let be the circumferential integer wave number. Substituting the above formulas (Formulas 19, 20, and 21) into the expression for the total potential energy П (Formula 11), we can obtain the total potential energy with respect to . , and The function, where Represents axial displacement components Fourier series amplitude coefficients, Represents circumferential displacement components Fourier series amplitude coefficients, Radial displacement component The Fourier series amplitude coefficients.

[0050] Based on the principle of minimum total potential energy, let about , and If all first-order partial derivatives are zero, then the linear buckling load of the column segment can be derived. ,as follows: ; Formula 22 Among them, all They are all matrix elements of the characteristic stiffness matrix (3×3 buckling stiffness matrix).

[0051] ; Formula 23 ; Formula 24 ; Formula 25 ; Formula 26 ; Formula 27 ; Formula 28 By changing the formula above and A series of linear buckling loads can be obtained from the values. The minimum value among the values ​​is the critical linear buckling load. If the critical linear buckling load is less than the minimum linear buckling load in the task indicators determined in step S510, it is determined that the task indicators are not met, and the process returns to step S520; otherwise, the process continues to step S560.

[0052] Step S560: Establish a complete finite element numerical model of the column segment body to solve the critical nonlinear buckling load, and check whether the critical nonlinear buckling load meets the requirements of the task indicators. If it meets the requirements, the design is completed; otherwise, return to step S510. After step S550 determines that the critical linear buckling load is not less than the minimum linear buckling load in the task indicators determined in step S510, a complete finite element numerical model is established for the column segment 2. Geometric nonlinear buckling analysis under axial compression is carried out using the arc length method (Riks method) to obtain the load-displacement response curve. The load peak value in the load-displacement response curve is taken as the nonlinear buckling load. If the nonlinear buckling load does not meet the requirements of the nonlinear buckling load in the task indicators, step S510 is returned to be executed; otherwise, the design of the column segment 2 is completed.

[0053] In one specific embodiment, combined with Figure 6a and Figure 6b As shown, the column segment body 2 with only extrusion ribs (T-type extrusion ribs 212 and I-type extrusion ribs 213) features and the column segment body 2 with extrusion ribs (T-type extrusion ribs 212 and I-type extrusion ribs 213) + milled ribs 214 features have the same weight. The arc length method is used to perform nonlinear buckling analysis of the column segment body 2 with the two structures under axial compression load, and the buckling deformation under the same axial load is compared.

[0054] The results show that the buckling mode of column segment 2 with only extrusion ribs is inward concavity in one region, with a concavity displacement of 19.2 mm; the buckling mode of column segment 2 with both extrusion ribs and milling ribs is also inward concavity in one region, with a concavity displacement of 15.3 mm, significantly lower than that of column segment 2 with only extrusion ribs. Figure 7a and Figure 7b Comparing the buckling history of the column segment 2 with the two structures, the buckling load of the column segment 2 with milled ribs is higher than that of the column segment 2 with only extrusion ribs.

[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A column section main body of a buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs, characterized in that, include: Multiple curved wall panels are joined together in a circumferential direction to form a cylindrical shell; The wall panels include: skin, extruded ribs, and milled ribs; The extrusion ribs are extruded together with the skin and the extension direction of the extrusion ribs is the same as the extrusion direction. The extrusion ribs are located on the outer side of the skin. The inner surface of the skin is milled to form milling ribs that intersect with the extrusion ribs.

2. The column section of the buckling-resistant sealing chamber with the synergistic effect of extruded ribs and milled ribs as described in claim 1, characterized in that, Extrusion ribs include: T-type extrusion ribs and I-type extrusion ribs; T-shaped extrusion ribs are distributed in the middle of the outer side of the skin and extend perpendicularly to the circumferential direction; Type I extrusion ribs are distributed on the edge of the outer side of the skin and extend perpendicularly to the circumferential direction. The positioning and splicing of two adjacent wall panels are achieved through the Type I extrusion ribs.

3. The column body of the buckling-resistant sealing chamber with the synergistic effect of extruded ribs and milled ribs as described in claim 1 or 2, characterized in that, Milled ribs include: milled ring ribs, milled diagonal ribs, and milled secondary ribs. The milled ribs extend in a circumferential direction; The milled ribs extend obliquely and intersect with the milled ring ribs; The milled secondary ribs are distributed around the intersection of the milled oblique ribs and the milled annular ribs.

4. The column section of the buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs as described in claim 2, characterized in that, The outer surface of the skin has multiple T-shaped extrusion ribs, all of which are arranged in equal phase.

5. A column segment of a buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs, characterized in that, It includes: an upper frame, a lower frame, and a column segment body as described in any one of claims 1 to 4; the upper end of the column segment body is fixedly connected to the upper frame, and the lower end of the column segment body is fixedly connected to the lower frame.

6. The column segment of the buckling-resistant sealing chamber with synergistic effect of extruded ribs and milled ribs as described in claim 5, characterized in that, The wall panel also includes: Type E connectors and Type I connectors; Both the upper and lower frames include: an annular base, a welded support, and multiple short ribs; The side of the annular base is fixedly connected to the welded support, the skin is welded to the welded support of the upper frame, and the skin is welded to the welded support of the lower frame; the inner edge of the short rib is fixedly connected to the outer side of the welded support, and the short rib is opposite to the T-shaped extruded rib and the I-shaped extruded rib. The E-type connector is located at the joint between the I-type extruded rib and the short rib, and the outer part of the I-type extruded rib and the outer part of the short rib are inserted into the connecting groove of the E-type connector facing inward. The type I connector is located at the junction of the T-shaped extrusion rib and the short rib, with the lower part of the short rib inserted into the upper connecting groove of the type I connector. The lower connecting strip of the type I connector is connected to the vertical rod of the T-shaped extrusion rib, and the lower pressing strip of the type I connector presses against the outside of the horizontal rod of the T-shaped extrusion rib.

7. The column segment of the buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs as described in claim 5 or 6, characterized in that, Also includes: In-cabin equipment; The inner surface of the skin is also milled to form equipment mounting bases, and the equipment inside the cabin is installed onto the mounting bases.

8. The column segment of the buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs as described in claim 5 or 6, characterized in that, Also includes: Circumferential hoop, which is installed on the inner side of the skin.

9. A buckling-resistant sealing chamber with synergistic action of extruded ribs and milled ribs, characterized in that, include: The upper conical segment and the column segment as described in any one of claims 5 to 8, wherein the column segment is fixedly connected to the upper conical segment via an upper end frame.

10. A design method for a column section of a buckling-resistant sealing chamber with synergistic effects of extruded and milled ribs, characterized in that, Specifically, the following steps are included: Step S510: Determine the task indicators and structural shape parameters of the column segment based on actual task requirements; Step S520: Using task indicators and structural shape parameters as constraints, initialize the dimensional parameters of skin, extrusion ribs, and milling ribs, and complete the pre-design of non-uniform rib layout. Step S530: Using the pre-designed skin and stiffeners of the non-uniform layout as the modeling basis, divide the structural unit cells and establish a unit cell finite element model for the structural unit cells. Step S540: Based on the numerical asymptotic homogenization method, obtain the equivalent stiffness coefficient of the structural unit cell according to the unit cell finite element model; Step S550: Substitute the equivalent stiffness coefficient into the Rayleigh-Ritz formula to analyze the critical linear buckling load of the column segment and determine whether it meets the requirements of the task index. If it does, proceed to step S560; otherwise, return to step S520. Step S560: Establish a complete finite element numerical model of the column segment and solve for the critical nonlinear buckling load. Check whether the critical nonlinear buckling load meets the requirements of the task indicators. If it does, the design is completed; otherwise, return to step S510.

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