Variable cross-section equal rigidity pressure-resistant shell annular rib structure

Abstract

The present application belongs to the field of submersible pressure hull application, and particularly relates to a variable cross-section equal rigidity pressure hull ring rib structure. The variable cross-section equal rigidity pressure hull ring rib structure comprises a plurality of arc-shaped connecting segments arranged in a ring array and a plurality of support segments arranged between the arc-shaped connecting segments; the arc-shaped connecting segment is in an I-shaped cross-section, comprising an arc-shaped and coaxially arranged panel and a lapping plate, and a web plate between the panel and the lapping plate; the inner edge of the web plate is connected with the outer lateral wall surface of the panel; and the thickness of the support segment is not less than the thickness of the arc-shaped connecting segment. The variable cross-section equal rigidity pressure hull ring rib structure is designed in a variable cross-section rib and equipment rack co-molding mode, and is used in a pressure hull of a marine vehicle, an aircraft fuselage shell and other large equipment needing to bear loads, and can bear single load such as axial pressure or multi-directional load combined action such as static water pressure, so that the spatial utilization rate and the bearing capacity of the structure are doubled through the rib.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of pressure hulls of underwater vehicles, and particularly relates to a variable cross-section equal-rigidity pressure hull annular rib structure. BACKGROUND

[0002] The pressure hull is one of indispensable structures of an underwater vehicle, and its carrying capacity and internal space utilization rate are important indexes for measuring the performance of the structure. The annular ribbed mode can significantly improve the carrying capacity of the pressure hull, but on the other hand, most of the equipment is square or other polygonal cross-section structure, and the edges or corners thereof are mainly fixed through the connection with the ribs. In order to simplify the connection structure, shorten the distance between the fixed point and the center, and ensure that the equipment or structure can be stably fixed, it is necessary to make the connection point as close to the equipment as possible. Meanwhile, in order to strengthen the overall strength of the underwater vehicle and reduce the pressure, the outer diameter size of the hull including the ribs should be as small as possible. Therefore, in the process of designing the internal structure of the underwater vehicle, the minimum size of the annular rib is limited, and when the equipment at the position is large in size, the fixing performance of the equipment and the optimization of the overall size of the underwater vehicle are difficult to be considered. In actual engineering application, the basic cross-section of the main equipment is basically rectangular, and the circular inscribed rectangle mode will cause a large waste of space. SUMMARY

[0003] The purpose of the present application is to provide a variable cross-section equal-rigidity pressure hull annular rib which can effectively strengthen the fixing effect of the internal equipment of the underwater vehicle, compress the size of the annular rib, and control the overall size of the underwater vehicle, and to provide a design optimization method thereof, so as to solve the contradiction between the size of the internal equipment of the pressure hull and the structural size and space utilization.

[0004] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions.

[0005] A variable cross-section equal-rigidity pressure hull annular rib structure comprises a plurality of arc-shaped connecting segments 1 arranged in a ring array and a plurality of support segments 2 arranged between the arc-shaped connecting segments 1.

[0006] The arc-shaped connecting segment 1 is in the shape of an I-beam, comprising an arc-shaped panel 10 and a lap plate 11 arranged coaxially, and a web plate 12 arranged between the panel 10 and the lap plate 11.

[0007] The inner edge of the web plate 12 is connected with the outer side wall surface of the panel 10, the outer edge is connected with the inner side of the lap plate 11, and the left and right edges are connected with the support segments 2, respectively.

[0008] The thickness of the support segment 2 is not less than the thickness of the arc-shaped connecting segment, the arc-shaped connecting segment uniformly transitions to the support segment 2 to form a variable cross-section transition zone 20, and a positioning groove 21 is dug on the inner side wall surface of the support segment 2.

[0009] Further improvement or optimization of the foregoing variable cross-section equal rigidity pressure shell annular rib, the arc-shaped connecting section 1 has uniform length, and the support section 2 is uniformly arranged in a ring array.

[0010] Further improvement or optimization of the foregoing variable cross-section equal rigidity pressure shell annular rib, the outer surface of the support section 2 is provided with an auxiliary positioning hole 23; and the panel 10 and the lap plate 11 are provided with a connecting hole 90.

[0011] Further improvement or optimization of the foregoing variable cross-section equal rigidity pressure shell annular rib, the positioning groove 21 refers to an axial positioning groove dug along the arc-shaped connecting section 1 in the axial direction, or a radial positioning groove dug along the arc-shaped connecting section 1 in the radial direction, or a combination of the axial positioning groove and the radial positioning groove.

[0012] Further improvement or optimization of the foregoing variable cross-section equal rigidity pressure shell annular rib, a positioning hole 22 is dug in the groove bottom or inner wall of the positioning groove 21.

[0013] A design method of a variable cross-section equal rigidity pressure shell annular rib, comprising the following steps:

[0014] 1. Collect performance parameters, including rib critical rigidity.

[0015] 2. Determine the basic structure parameters of the annular rib, specifically referring to: determining the maximum design radius of the rib according to the size of the pressure shell or equipment, and determining the specific size of the equipment to be positioned or installed and the size of the required installation space according to the type of the equipment to be positioned or installed;

[0016] 3. Determine the structure parameters of the arc-shaped connecting section, specifically referring to: based on the Euler-Bernoulli beam theory, taking a unit length of the pressure shell as a beam along the axis, regarding the annular rib as an elastic support on the beam, establishing a beam model, and obtaining the bending rigidity D J of the pressure shell rib and the bending rigidity D B of the shell plate of the pressure shell;

[0017] D J = E q1 I1+E q2 I2 1

[0018]

[0019] In the formula: E q1 and E q2 respectively represent the equivalent elastic modulus of the plate beam reinforcement and the plate; I1 and I2 respectively represent the moment of inertia of the plate beam reinforcement and the plate to the neutral axis of the plate beam; d represents the thickness of the shell plate of the pressure shell; μ is the material Poisson's ratio;

[0020] Taking the neutral axis of the shell plate of the pressure-resistant shell as the coordinate origin, a plate-stiffener rigidity ratio β expression is obtained:

[0021]

[0022] In the formula, b' represents the plate width of the stiffener; b represents the width of the stiffener; h represents the height of the stiffener;

[0023] Y represents the height of the neutral axis of the stiffener and its plate structure, and

[0024] A dimensionless quantity is defined The plate-stiffener rigidity ratio expression of the stiffened plate is obtained by substituting formula 4 into formula 3:

[0025]

[0026] b' is the plate width of the stiffener, and B represents the horizontal distance between two adjacent pressure-resistant shell ribs;

[0027] The plate-stiffener rigidity ratio curve of the stiffened plate is drawn based on formula 6, the corresponding m value of the stiffener width is found according to the plate-stiffener rigidity ratio requirement of the pressure-resistant shell, the height h of the stiffener is calculated, and the preliminary design scheme of the stiffener of the stiffened plate is obtained;

[0028] 4. Determine the basic structure parameters of the support section, specifically referring to: taking the section with the minimum height of the support section 2 for design, and adjusting the structure parameters according to the equal rigidity principle to make the rigidity of the variable cross-section region rib not lower than the rigidity of the normal rib.

[0029] Further improvement or supplement to the foregoing variable cross-section equal rigidity pressure-resistant shell annular rib design method also includes step 5, design scheme refinement adjustment, specifically referring to: based on finite element simulation to check the strength and stability, if the check fails, return to step 4 to adjust again.

[0030] The beneficial effects are that:

[0031] The variable cross-section equal rigidity pressure-resistant shell annular rib structure of the application adopts a variable cross-section rib and a device rack co-molded design, which is used in the pressure-resistant shell of a marine vehicle, the fuselage shell of an aircraft and other large equipment that needs to bear load, and can bear single load such as axial pressure or multi-directional load such as hydrostatic pressure, so that the spatial utilization rate and load bearing capacity of the structure are doubled. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a structural schematic diagram of the variable cross-section annular rib of the submarine in the embodiment;

[0033] Figure 2 is an assembly schematic diagram of the variable cross-section annular rib of the submarine in the embodiment;

[0034] Figure 3 is a schematic diagram of the extended structure of the variable cross-section submarine ring rib;

[0035] Figure 4 is a schematic diagram of the installation method of the internal equipment of the submarine;

[0036] Figure 5 is a schematic diagram of the installation method of the variable cross-section submarine ring rib. DETAILED DESCRIPTION

[0037] The application will be described in detail below in combination with specific embodiments.

[0038] The variable cross-section ring rib structure of the equal rigidity pressure-resistant shell of the application is improved and designed based on the traditional equal cross-section ring rib structure. In addition to including a plurality of arc-shaped connecting sections 1 arranged in a ring array, it also includes a plurality of support sections 2 arranged between the arc-shaped connecting sections 1. The arc-shaped connecting sections 1 and the support sections 2 are thus connected to form a ring rib structure.

[0039] The variable cross-section ring rib structure of the application is consistent with the traditional ring rib structure in terms of basic construction and installation and fixing method. The arc-shaped connecting section 1 has a traditional I-shaped or extended T-shaped structure, which mainly includes an arc-shaped and coaxial panel 10 and a lapping plate 11, and a web 12 between the panel 10 and the lapping plate 11.

[0040] The arc-shaped connecting section 1 is a conventional rib area, and its design parameters and dimensions are consistent with the design method and parameters of the conventional equal cross-section ring rib. The support section 2 is a variable cross-section rib area, which is thickened but provided with groove and hole structures for installing and fixing equipment, so its specific structural parameters should be calculated and tested based on structural mechanics to ensure bearing.

[0041] The structural materials of the arc-shaped connecting section 1 and the support section 2 are consistent with those of the traditional rib, and generally use metal or composite materials.

[0042] As shown in Figures 1-3 , the specific structure is as follows: the inner edge of the web 12 is connected with the outer side wall surface of the panel 10, the outer edge is connected with the inner side of the lapping plate 11, and the left and right edges are respectively connected with the support section 2.

[0043] The thickness of the support section 2 is not less than the thickness of the arc-shaped connecting section, and the arc-shaped connecting section uniformly transitions to the support section 2 to form a variable cross-section transition zone 20, and a positioning groove 21 is dug on the inner side wall surface of the support section 2.

[0044] The positioning groove 21 is used for clamping or fixing the corner or connecting structure of the equipment, and is preferably an axial positioning groove dug along the axial direction of the arc-shaped connecting section 1, or a radial positioning groove dug along the radial direction of the arc-shaped connecting section 1, or a combination of the axial positioning groove and the radial positioning groove.

[0045] In order to facilitate the fastening and positioning, a positioning hole 22 is dug on the groove bottom or inner wall of the positioning groove 21.

[0046] In order to ensure uniform stress in all directions, in the preferred structure, the arc-shaped connecting section 1 has a uniform length, and the support section 2 is arranged in a ring array.

[0047] In order to improve the strength of the equipment connecting point and ensure the integrity and effectiveness, an auxiliary positioning hole 23 is arranged on the outer surface of the support section 2; and a connecting hole 90 is arranged on the panel 10 and the lap plate 11.

[0048] In order to improve the design efficiency of the foregoing variable cross-section ring rib structure and simplify the design steps, the following provides a design optimization scheme for the foregoing structure, which specifically includes the following steps:

[0049] 1. Collect performance parameters, including rib critical stiffness.

[0050] 2. Determine the basic structure parameters of the ring rib, specifically referring to: determining the maximum design radius of the rib according to the size of the pressure-resistant shell or equipment, and determining the specific size of the equipment to be positioned or installed and the size of the required installation space;

[0051] 3. Determine the structure parameters of the arc-shaped connecting section, specifically referring to: based on the Euler-Bernoulli beam theory, taking a unit length of the pressure-resistant shell as a beam along the axis, regarding the ring rib as an elastic support on the beam, establishing a beam model, and obtaining the bending stiffness D J of the pressure-resistant shell rib and the bending stiffness D B of the shell plate of the pressure-resistant shell.

[0052] D J = E q1 I1+E q2 I2 1

[0053]

[0054] In the formula, E q1 and E q2 respectively represent the equivalent elastic modulus of the plate beam reinforcement and the plate; I1 and I2 respectively represent the inertia moment of the plate beam reinforcement and the plate to the neutral axis of the plate beam; d represents the thickness of the shell plate of the pressure-resistant shell; μ is the material Poisson's ratio.

[0055] Taking the neutral axis of the shell plate of the pressure-resistant shell as the coordinate origin, the expression of the plate-reinforcement stiffness ratio β is obtained.

[0056]

[0057] In the formula: b' represents the width of the strip; b represents the width of the reinforcing bar; h represents the height of the reinforcing bar;

[0058] Y represents the neutral axis height of the reinforcing bar and its strip-plate structure, and

[0059] Define dimensionless quantity Substituting back into Equation 4, we obtain the expression for the stiffness ratio of the reinforced slab:

[0060]

[0061] b′ refers to the width of the reinforcing strip and B represents the horizontal distance between two adjacent pressure-resistant shell ribs;

[0062] Based on Equation 6, the stiffness ratio curve of the stiffened plate is plotted. According to the stiffness ratio requirement of the pressure shell, the corresponding m value of the stiffener width is found, the height h of the stiffener is calculated, and the preliminary design scheme of the stiffener of the stiffened plate is obtained.

[0063] 4) Determine the basic structural parameters of the support section. Specifically, this means: design the section with the smallest height of support section 2, and adjust the structural parameters according to the principle of equal stiffness so that the stiffness of the ribs in the variable cross section area is not lower than the stiffness of the normal ribs.

[0064] 5) Detailed adjustment of the design scheme, specifically: strength and stability verification based on finite element simulation. If the verification fails, return to step 4 for readjustment.

[0065] The aforementioned variable cross-section, constant stiffness pressure hull annular rib structure and its design method of the present invention are basic implementation methods for non-applied technical solutions. In specific implementation, adaptive adjustments should be made according to the limitations and conditions of current underwater equipment or structural layouts, striving to ensure that the inner and outer diameters of conventional cylindrical underwater vehicles are relatively consistent, but their application is as follows... Figure 4 For the variable-size underwater vehicle shown, since its ring ribs are generally located at the minimum or maximum inner diameter lock position, the design should be based on the parameters of the corresponding structure and equipment at the location of this type of vehicle during the process of dimensional parameter and structural design.

[0066] Its specific implementation effect is illustrated as follows: Figure 5 As shown, R1 is the size required by the traditional ring rib when the maximum size of the device is L, and R2 is the corresponding ring size in the structure of this application. This is equivalent to using the thickness of the ring rib itself as a margin to expand the installation space of the device, thereby compressing the overall size of the device.

[0067] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A variable cross-section constant stiffness pressure hull ring frame structure, characterized by, The application relates to a variable cross-section equal-rigidity pressure-resistant shell ring rib structure. The cross section of the arc-shaped connecting section (1) is in the shape of an I-beam, and comprises an arc-shaped panel (10) and a lapping plate (11) which are coaxially arranged and a web (12) between the panel (10) and the lapping plate (11). The inner edge of the web (12) is connected with the outer lateral wall surface of the panel (10), the outer edge is connected with the inner lateral wall surface of the lapping plate (11), and the left and right edges are connected with the support sections (2). The thickness of the support section (2) is not less than that of the arc-shaped connecting section, the arc-shaped connecting section uniformly transitions to the support section (2) to form a variable cross-section transition area (20), and a positioning groove (21) is dug in the inner lateral wall surface of the support section (2). The variable cross-section equal-rigidity pressure-resistant shell ring rib structure is determined based on the following steps:

1. Collect performance parameters, including the critical rigidity of the rib; 2. Determine the basic structure parameters of the ring rib, specifically referring to: determining the maximum design radius of the rib according to the size of the pressure-resistant shell or equipment, and determining the specific size of the equipment and the size of the required installation space according to the type of the equipment to be positioned or installed; 3). Determine the structure parameters of the arc connection section, specifically: based on the Euler Bernoulli beam theory, take the unit length pressure-resistant shell along the axis as a beam, and regard the ring rib as an elastic support on the beam to establish a beam model, and obtain the bending stiffness D J of the pressure-resistant shell rib B ; （1） （2） wherein: E q1 and E q2 respectively represent the equivalent elastic modulus of the strip plate beam reinforcement and the strip plate; I1and I2respectively represent the moment of inertia of the strip plate beam reinforcement and the strip plate to the neutral axis of the strip plate beam; d represents the thickness of the shell plate of the pressure-resistant shell; and μ is the material Poisson's ratio; With the neutral axis of the shell plate of the pressure-resistant shell as the coordinate origin, the plate reinforcement stiffness ratio Expression: （4） In the formulae: denotes the strip width; b denotes the width of the reinforcement; h denotes the height of the reinforcement; Y represents the height of the neutral axis of the reinforcement and its plate structure and (5); Definition of dimensionless quantity , , Substituting equation (4) into equation (3) gives the expression of the stiffness ratio of the stiffened plate （6） is the width of the tendon strip with plate and B represents the horizontal distance between two adjacent pressure shell girders. Based on formula (6), the plate rib rigidity ratio curve is drawn, the m value corresponding to the rib width is found according to the plate rib rigidity ratio requirement of the pressure-resistant shell, the height h of the rib is calculated, and the preliminary design scheme of the ribbed plate is obtained; 4. Determine the basic structure parameters of the support section, specifically referring to: taking the cross section with the minimum height of the support section (2) for design, and adjusting the structure parameters according to the equal-rigidity principle to make the rigidity of the rib in the variable cross-section area not lower than that of the normal rib; 5. Fine adjustment of the design scheme, specifically referring to: performing strength and stability checking based on finite element simulation, and returning to step 4) for re-adjustment if the checking fails.

2. The variable cross-section isogrid pressure hull ring structure of claim 1, wherein, The lengths of the arc-shaped connecting sections (1) are consistent, and the support sections (2) are uniformly arranged in a ring array.

3. The variable cross-section isogrid pressure hull ring structure of claim 1, wherein, Auxiliary positioning holes (23) are arranged on the outer surface of the support section (2); and connecting holes (90) are arranged on the panel (10) and the lapping plate (11).

4. The variable cross-section isogrid pressure hull ring structure of claim 1, wherein, The positioning groove (21) refers to an axial positioning groove dug along the axial direction of the arc-shaped connecting section (1), or a radial positioning groove dug along the radial direction of the arc-shaped connecting section (1), or a combination of the axial positioning groove and the radial positioning groove.

5. The variable cross-section, constant-stiffness pressure hull ring structure of claim 4, wherein, Positioning holes (22) are dug in the groove bottom or inner wall of the positioning groove (21).

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