Method and device for determining deformation of fuselage frame under tensile load

Abstract

The invention belongs to the technical field of aircraft design, and particularly relates to a fuselage frame deformation determination method and device under a tensile load, and the method comprises the steps: S1, determining the radius R, the section rigidity I, the elastic modulus E and the borne symmetric tension F of a circular section of a fuselage frame; s2, constructing a polar coordinate system by taking the round point of the round section of the fuselage frame as a pole and taking the direction of the symmetrical tension as a polar axis, and determining a polar angle beta at the position of the fuselage frame with the deformation degree to be analyzed; and S3, determining transverse displacement and longitudinal displacement at the position of the fuselage frame. According to the method, the time of traditional finite element modeling calculation is shortened, and the design optimization efficiency of the fuselage reinforcing frame is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft design, and more particularly to a method and device for determining deformation of a fuselage frame under a tensile load. Background Art

[0002] The premise of optimizing the design of the fuselage frame is to determine the deformation at any position of the fuselage frame. In the prior art, the calculation is mainly performed by finite element analysis. The finite element model construction and calculation process of this method are complex, which wastes a lot of manpower and material resources. Summary of the invention

[0003] In order to solve the above problems, the present application provides a method and device for determining the deformation of a fuselage frame under a tensile load, and reconstructs the calculation model of the deformation of the fuselage frame using a theoretical calculation method to improve the calculation efficiency.

[0004] The first aspect of the present application provides a method for determining the deformation of a fuselage frame under a tensile load, mainly comprising:

[0005] Step S1, determining the radius R, section stiffness I, elastic modulus E and symmetrical tension F of the circular section of the fuselage frame;

[0006] Step S2, constructing a polar coordinate system with the point of the circular cross section of the fuselage frame as the pole and the direction of the symmetrical tension as the polar axis, and determining the polar angle β at the position of the fuselage frame whose deformation degree is to be analyzed;

[0007] Step S3: Determine the lateral displacement u at the fuselage frame position according to the following formula: x (β) and longitudinal displacement u y (β):

[0008]

[0009] Preferably, step S3 further includes:

[0010] Step S4: optimizing the structure of the fuselage frame according to the displacement at the position of the fuselage frame, so that the displacement at the position of the fuselage frame is less than a set value under the action of a specified symmetrical pulling force F.

[0011] Preferably, in step S4, optimizing the structure of the fuselage frame includes: replacing the material of the fuselage structure frame.

[0012] Preferably, in step S4, optimizing the structure of the fuselage frame includes: modifying the connection mode of the fuselage structure frame.

[0013] Preferably, in step S4, structural optimization of the fuselage frame includes: modifying the number, position and tension of prestressed tendons in the fuselage structure frame.

[0014] Preferably, in step S4, structural optimization of the fuselage frame includes: modifying the structural dimensions and topology optimization of the fuselage structure frame.

[0015] The second aspect of the present application provides a device for determining the deformation of a fuselage frame under a tensile load, mainly comprising:

[0016] A fuselage frame parameter determination module is used to determine the radius R, section stiffness I, elastic modulus E and symmetrical tension F of the circular section of the fuselage frame;

[0017] A fuselage frame position determination module is used to construct a polar coordinate system with the point of the circular cross section of the fuselage frame as the pole and the direction of the symmetrical tension as the polar axis to determine the polar angle β at the position of the fuselage frame whose deformation degree is to be analyzed;

[0018] The fuselage frame deformation calculation module is used to determine the lateral displacement u at the fuselage frame position according to the following formula x (β) and longitudinal displacement u y (β):

[0019]

[0020] Preferably, the device further comprises:

[0021] The fuselage frame optimization module is used to optimize the structure of the fuselage frame according to the displacement at the position of the fuselage frame, so that the displacement at the position of the fuselage frame is less than a set value under the action of a specified symmetrical pulling force F.

[0022] Preferably, in the fuselage frame optimization module, optimizing the structure of the fuselage frame includes: replacing the material of the fuselage structure frame.

[0023] Preferably, in the fuselage frame optimization module, optimizing the structure of the fuselage frame includes: modifying the connection mode of the fuselage structure frame.

[0024] Preferably, in the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the number, position and tension of prestressed tendons in the fuselage structure frame.

[0025] Preferably, in the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the structural dimensions and topology optimization of the fuselage structure frame.

[0026] A third aspect of the present application provides a computer device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for determining the deformation of a fuselage frame under a tensile load as described above.

[0027] A fourth aspect of the present application provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the method for determining the deformation of a fuselage frame under a tensile load as described above.

[0028] This application reduces the time of traditional finite element modeling calculations and improves the efficiency of fuselage reinforcement frame design optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of a preferred embodiment of the method for determining the deformation of the fuselage frame under tensile load of the present application.

[0030] Figure 2 It is a force diagram of the fuselage frame section of the present application in a polar coordinate system.

[0031] Figure 3 It is a schematic diagram of the 1 / 4 arc beam model of this application.

[0032] Figure 4 It is a schematic diagram of the lateral displacement at the polar angle β of the present application.

[0033] Figure 5 It is a schematic diagram of the longitudinal displacement at the polar angle β of the present application.

[0034] Figure 6 It is a schematic diagram of the structure of a computer device suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0036] In a first aspect, the present application provides a method for determining the deformation of a fuselage frame under a tensile load, such as Figure 1 As shown, it mainly includes:

[0037] Step S1, determining the radius R, section stiffness I, elastic modulus E and symmetrical tension F of the circular section of the fuselage frame;

[0038] Step S2, constructing a polar coordinate system with the point of the circular cross section of the fuselage frame as the pole and the direction of the symmetrical tension as the polar axis, and determining the polar angle β at the position of the fuselage frame whose deformation degree is to be analyzed;

[0039] Step S3: Determine the lateral displacement u at the fuselage frame position according to the following formula: x (β) and longitudinal displacement u y (β):

[0040]

[0041] The formula of step S3 of the present application is explained as follows.

[0042] For the circular cross-section fuselage reinforcement frame, when it is subjected to symmetrical tensile load, it can be simplified as follows: Figure 2 The mechanical model shown in the figure takes the center of the circle as the origin and establishes a polar coordinate system. According to the load and constraint symmetry conditions, the 1 / 4 arc beam model is obtained as follows: Figure 3 shown.

[0043] Figure 3 In the figure, point A constrains translation in the X direction and rotation in the Z direction, and point B constrains translation in the Y direction only. An unknown bending moment X1 is applied at section B. According to the deformation coordination condition:

[0044]

[0045] Where M is the bending moment of the statically determinate model beam, is the bending moment produced by unit force,

[0046] Substituting formula (2) (3) into (1), we get: The negative sign indicates that the bending moment is in the opposite direction to that initially assumed.

[0047] Then calculate the bending moment produced by the unit force and find the displacement u of any point B' on the arc x (β),u y (β), we need to construct a unit force system such as Figure 4 , Figure 5 shown.

[0048] Bending moment caused by horizontal unit force:

[0049] Bending moment due to vertical unit force:

[0050] Finally, the lateral displacement u of any point B' on the arc at angle β is calculated by the unit load method: x (β) and longitudinal displacement u y (β).

[0051] Transverse displacement ux (β):

[0052]

[0053] Find:

[0054] Longitudinal displacement u y (β):

[0055]

[0056] Find:

[0057] Assume that the fuselage reinforcement frame of an aircraft is a circle with a radius of R = 2500 mm, and ignore the influence of the surrounding skin deformation on the reinforcement frame. The section stiffness of the reinforcement frame is I = 10 6 mm 4 , the elastic modulus is E = 70GPa, and it is in a self-balanced state under the symmetrical tensile force F = 1000N. The position reaction force is calculated according to the deformation coordination condition Substituting the formula in step S3 yields:

[0058] When β=0°, the deformation in X direction is the largest, u xmax =u x (0°) = 16.6 mm;

[0059] When β=90°, the Y-axis deformation is the largest, u ymax =u y (90°)=-15.4mm.

[0060] The present application obtains the deformation law of the circular reinforcement frame of the fuselage under the action of symmetrical tensile load through a theoretical method, which reduces the time of traditional finite element modeling and calculation and improves the design optimization efficiency of the fuselage reinforcement frame.

[0061] In some optional implementations, step S3 further includes:

[0062] Step S4: optimizing the structure of the fuselage frame according to the displacement at the position of the fuselage frame, so that the displacement at the position of the fuselage frame is less than a set value under the action of a specified symmetrical pulling force F.

[0063] In some optional implementations, in step S4, optimizing the structure of the fuselage frame includes: replacing the material of the fuselage structure frame. This embodiment provides that the rigidity of the fuselage frame is improved by optimizing the material, and the use of new materials such as high-strength fiberglass, carbon fiber, etc. can also significantly improve the strength and durability of the structure.

[0064] In some optional implementations, in step S4, optimizing the structure of the fuselage frame includes: modifying the connection mode of the fuselage structure frame. This embodiment provides a method of improving the rigidity of the fuselage frame by optimizing parameters, such as the connection mode of hardware parts, the connection mode of beams and columns, etc., to optimize the performance of the entire structure.

[0065] In some optional implementations, in step S4, structural optimization of the fuselage frame includes: modifying the number, position and tension of prestressed tendons in the fuselage structure frame.

[0066] In some optional implementations, in step S4, structural optimization of the fuselage frame includes: modifying the structural dimensions and topology optimization of the fuselage structure frame.

[0067] In this embodiment, the strength and stability of the structure can be improved by optimizing the cross-sectional parameters or overall geometric dimensions of beams and slabs. The size optimization technology is relatively mature, and can adopt the method based on scattered points, gradient method or heuristic algorithm. Topological optimization mainly refers to the change of data such as connection mode and internal opening position, which is suitable for improving the overall performance of complex structures and optimizing the overall performance by changing the topological form of the structure.

[0068] The second aspect of the present application provides a device for determining the deformation of a fuselage frame under a tensile load corresponding to the above method, mainly comprising:

[0069] A fuselage frame parameter determination module is used to determine the radius R, section stiffness I, elastic modulus E and symmetrical tension F of the circular section of the fuselage frame;

[0070] A fuselage frame position determination module is used to construct a polar coordinate system with the point of the circular cross section of the fuselage frame as the pole and the direction of the symmetrical tension as the polar axis to determine the polar angle β at the position of the fuselage frame whose deformation degree is to be analyzed;

[0071] The fuselage frame deformation calculation module is used to determine the lateral displacement u at the fuselage frame position according to the following formula x (β) and longitudinal displacement u y (β):

[0072]

[0073] In some optional embodiments, the device further comprises:

[0074] The fuselage frame optimization module is used to optimize the structure of the fuselage frame according to the displacement at the position of the fuselage frame, so that the displacement at the position of the fuselage frame is less than a set value under the action of a specified symmetrical pulling force F.

[0075] In some optional implementations, in the fuselage frame optimization module, optimizing the structure of the fuselage frame includes: replacing the material of the fuselage structure frame.

[0076] In some optional implementations, in the fuselage frame optimization module, optimizing the structure of the fuselage frame includes: modifying the connection method of the fuselage structure frame.

[0077] In some optional implementations, in the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the number, position and tension of prestressed tendons in the fuselage structure frame.

[0078] In some optional implementations, in the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the structural dimensions and performing topological optimization on the fuselage structure frame.

[0079] In a third aspect of the present application, a computer device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a method for determining a fuselage frame deformation under a tensile load.

[0080] In a fourth aspect of the present application, a readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the method for determining the deformation of a fuselage frame under a tensile load as described above. The computer-readable storage medium may be included in the device described in the above embodiment; or it may exist independently without being assembled into the device. The computer-readable storage medium carries one or more programs, and when the one or more programs are executed by the device, the data is processed according to the above method.

[0081] Reference below Figure 6 , which shows a schematic structural diagram of a computer device 400 suitable for implementing the embodiments of the present application. Figure 6 The computer device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0082] like Figure 6 As shown, the computer device 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage part 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the device 400 are also stored. The CPU 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0083] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, etc.; an output section 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, a modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to the I / O interface 405 as needed. A removable medium 411, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 410 as needed, so that a computer program read therefrom is installed into the storage section 408 as needed.

[0084] In particular, according to the embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 409, and / or installed from the removable medium 411. When the computer program is executed by the central processing unit (CPU) 401, the above functions defined in the method of the present application are executed. It should be noted that the computer storage medium of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, - but not limited to - a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, an apparatus or a device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, an apparatus or a device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0085] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0086] The modules or units involved in the embodiments described in this application may be implemented by software or hardware. The modules or units described may also be set in a processor, and the names of these modules or units do not constitute limitations on the modules or units themselves in some cases.

[0087] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for determining the deformation of a fuselage frame under a tensile load, characterized in that: include: Step S1, determining the radius R, section stiffness I, elastic modulus E and symmetrical tension F of the circular section of the fuselage frame; Step S2, constructing a polar coordinate system with the point of the circular cross section of the fuselage frame as the pole and the direction of the symmetrical pulling force as the polar axis, and determining the polar angle β at the position of the fuselage frame whose deformation degree is to be analyzed; Step S3: Determine the lateral displacement u at the fuselage frame position according to the following formula: x (β) and longitudinal displacement u y (β):

2. The method for determining the deformation of a fuselage frame under a tensile load according to claim 1, characterized in that: Step S3 further includes: Step S4: optimizing the structure of the fuselage frame according to the displacement at the position of the fuselage frame, so that the displacement at the position of the fuselage frame is less than a set value under the action of a specified symmetrical pulling force F.

3. The method for determining the deformation of a fuselage frame under a tensile load according to claim 2, characterized in that: In step S4, optimizing the structure of the fuselage frame includes: replacing the material of the fuselage structure frame.

4. The method for determining the deformation of a fuselage frame under a tensile load according to claim 2, wherein: In step S4, optimizing the structure of the fuselage frame includes: modifying the connection mode of the fuselage structure frame.

5. The method for determining the deformation of a fuselage frame under a tensile load according to claim 2, characterized in that: In step S4, structural optimization of the fuselage frame includes: modifying the number, position and tension of prestressed tendons in the fuselage structure frame.

6. The method for determining the deformation of a fuselage frame under a tensile load according to claim 2, characterized in that: In step S4, structural optimization of the fuselage frame includes: modifying the structural dimensions and topology optimization of the fuselage structure frame.

7. A device for determining the deformation of a fuselage frame under a tensile load, characterized in that: include: A fuselage frame parameter determination module is used to determine the radius R, section stiffness I, elastic modulus E and symmetrical tension F of the circular section of the fuselage frame; A fuselage frame position determination module is used to construct a polar coordinate system with the point of the circular cross section of the fuselage frame as the pole and the direction of the symmetrical tension as the polar axis to determine the polar angle β at the position of the fuselage frame whose deformation degree is to be analyzed; The fuselage frame deformation calculation module is used to determine the lateral displacement u at the fuselage frame position according to the following formula x (β) and longitudinal displacement u y (β):

8. The device for determining the deformation of a fuselage frame under a tensile load according to claim 7, characterized in that: The device further comprises: The fuselage frame optimization module is used to optimize the structure of the fuselage frame according to the displacement at the position of the fuselage frame, so that the displacement at the position of the fuselage frame is less than a set value under the action of a specified symmetrical pulling force F.

9. The device for determining the deformation of a fuselage frame under a tensile load according to claim 8, characterized in that: In the fuselage frame optimization module, optimizing the structure of the fuselage frame includes: replacing the material of the fuselage structure frame.

10. The device for determining the deformation of a fuselage frame under a tensile load according to claim 8, characterized in that: In the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the connection mode of the fuselage structure frame.

11. The device for determining the deformation of a fuselage frame under a tensile load according to claim 8, characterized in that: In the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the number, position and tension of prestressed tendons in the fuselage structure frame.

12. The device for determining the deformation of a fuselage frame under a tensile load according to claim 8, characterized in that: In the fuselage frame optimization module, structural optimization of the fuselage frame includes: modifying the structural dimensions and topological optimization of the fuselage structure frame.

13. A computer device, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for determining the deformation of a fuselage frame under a tensile load as claimed in any one of claims 1 to 6.

14. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it is used to implement the method for determining the deformation of a fuselage frame under a tensile load as described in any one of claims 1 to 6.

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