A cylindrical thin-walled part and a method for designing a circumferential reinforcing rib topology thereof

Abstract

The application provides a cylindrical thin-wall part and a hoop stiffener topology design method thereof, and belongs to the field of aircraft structure design, and comprises the following steps: determining a topology design area of a hoop stiffener of a cylindrical thin-wall part, topologically predetermining the thickness of the skin of the cylindrical thin-wall part in the thickness direction, and the space formed by the topology predetermination thickness is the topology design domain of the hoop stiffener of the cylindrical thin-wall part; establishing topology design optimization constraints and targets of the hoop stiffener of the cylindrical thin-wall part; according to the actual load condition of the cylindrical thin-wall part and the actual connection condition with the surrounding structure, pressure load is applied to the inner wall of the cylindrical thin-wall part and the degree of freedom displacement constraint is established; hoop stiffener topology design simulation analysis is carried out on the cylindrical thin-wall part, and the hoop stiffener layout under the maximum stiffness constraint is obtained; the obtained cylindrical thin-wall part is subjected to hoop stiffener processability checking, if the processability requirement is not met, the constraint symmetry plane is adjusted, and finally the hoop stiffener topology design scheme is obtained.

Description

Technical Field

[0001] This application belongs to the field of aircraft structural design technology, and specifically relates to a cylindrical thin-walled part and its circumferential stiffener topology design method. Background Technology

[0002] Cylindrical thin-walled components are typical parts in aircraft structures and have wide applications, such as aircraft air intake structures and nozzle structures. These components typically bear pressure loads within the cylindrical duct, thus requiring circumferential stiffeners to meet load-bearing requirements. Currently, uniformly distributed annular stiffeners are commonly used. However, for some cylindrical thin-walled components subjected to complex pressure loads, traditional circumferential stiffeners are too heavy and difficult to meet design requirements. Therefore, a method is needed to perform topological design of the stiffener orientation based on load characteristics, thereby creating a circumferential stiffener scheme that adapts to the load type. Summary of the Invention

[0003] The purpose of this application is to provide a cylindrical thin-walled part and a topology design method for its circumferential stiffeners, so as to solve or alleviate at least one of the problems in the prior art.

[0004] The technical solution of this application is: a topology design method for circumferential stiffeners of cylindrical thin-walled parts, including:

[0005] Step S1: Determine the topology design region of the circumferential stiffener of the cylindrical thin-walled part, and topologically design the skin of the cylindrical thin-walled part within the topology design region along the thickness direction to a predetermined thickness. The space formed by the predetermined thickness is the topology design domain of the circumferential stiffener of the cylindrical thin-walled part.

[0006] Step S2: Establish topology design optimization constraints for the circumferential stiffeners of the cylindrical thin-walled part;

[0007] Step S3: Establish the topology design target for the circumferential stiffeners of the cylindrical thin-walled part;

[0008] Step S4: Apply pressure load and establish degree-of-freedom displacement constraints on the inner wall of the cylindrical thin-walled part according to the actual load condition of the cylindrical thin-walled part and the actual connection with the surrounding structure.

[0009] Step S5: Perform simulation analysis on the topology design of the circumferential stiffeners for the cylindrical thin-walled part to obtain the circumferential stiffener layout that satisfies the constraints of Step S2 and Step S3 to achieve the maximum stiffness.

[0010] Step S6: Perform a process check on the circumferential stiffeners of the cylindrical thin-walled part obtained in step S5. If the process requirements of the circumferential stiffener layout are not met, adjust the constraint symmetry plane and repeat steps S3 to S5 until the process requirements of the circumferential stiffener layout are met, and finally obtain the topology design scheme of the circumferential stiffeners of the cylindrical thin-walled part.

[0011] In a preferred embodiment of the present invention, the predetermined thickness of the topology is 20% of the radius of the cylindrical thin-walled part.

[0012] In a preferred embodiment of the present invention, the optimization constraints include volume fraction constraints, stress constraints, and processability constraints, wherein:

[0013] (1) The volume fraction constraint is that the volume of the circumferential stiffener of the cylindrical thin-walled part after topology design shall not exceed 10% of the topology design domain;

[0014] (2) The stress constraint is that the stress level of the circumferential stiffener of the cylindrical thin-walled part after topology design is not greater than the allowable stress of the material of the cylindrical thin-walled part;

[0015] (3) The process constraint is that the circumferential stiffeners of the cylindrical thin-walled parts are directly connected to the skin after the topology design.

[0016] In a preferred embodiment of the present invention, the topology design objective is to maximize the stiffness of the circumferential stiffeners of the cylindrical thin-walled part.

[0017] In a preferred embodiment of the present invention, the constraint symmetry plane is a plane passing through the center point of the cylindrical thin-walled part.

[0018] On the other hand, the present invention provides a cylindrical thin-walled part, which is obtained by the circumferential stiffener topology design method for cylindrical thin-walled parts as described above.

[0019] The topology design method for circumferential stiffeners of cylindrical thin-walled parts provided by the present invention can establish a circumferential stiffener layout scheme that is adapted to the load height of the cylindrical thin-walled parts. Compared with the traditional uniformly distributed annular stiffeners, the stiffener layout scheme obtained by the method of the present invention has a lower structural weight. Attached Figure Description

[0020] To more clearly illustrate the technical solutions provided in this application, the accompanying drawings will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application.

[0021] Figure 1 This is a schematic diagram of the topology design method for the circumferential stiffeners of the cylindrical thin-walled parts of the present invention.

[0022] Figure 2 This is a schematic diagram of a typical thin-walled cylindrical part with uniformly distributed annular reinforcing ribs.

[0023] Figure 3 The intention is to remove the uniformly distributed annular reinforcing ribs from the cylindrical thin-walled part to be designed.

[0024] Figure 4 This is a schematic diagram of the topological simulation analysis results of the circumferential stiffener of a cylindrical thin-walled part in one embodiment of the present invention.

[0025] Figure 5 For based on Figure 4 The simulation analysis results yielded the topology scheme for the circumferential stiffeners of the cylindrical thin-walled part. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings.

[0027] To address the problem that conventional annular stiffeners cannot meet design requirements (weight) under complex load conditions, this invention provides a topology design method for circumferential stiffeners in cylindrical thin-walled parts. This method enables the topology design of circumferential stiffeners in cylindrical thin-walled parts, forming a circumferential stiffener structure that adapts to load characteristics and reduces the structural weight of cylindrical thin-walled parts.

[0028] like Figure 1 As shown, the topology design method for circumferential stiffeners of cylindrical thin-walled parts provided by the present invention includes the following steps:

[0029] Step S1: Determine the topology design region of the circumferential stiffener of the cylindrical thin-walled part, and topologically design the skin of the cylindrical thin-walled part in the thickness direction with a predetermined thickness. The space formed by this topological thickness is the topology design domain of the circumferential stiffener of the cylindrical thin-walled part.

[0030] like Figure 2 The diagram shows a typical cylindrical thin-walled part with uniformly distributed annular reinforcing ribs. In the cylindrical thin-walled part 10 with uniformly distributed annular reinforcing ribs, the flanges 11 on both sides and in the middle constitute the connection between the cylindrical thin-walled part 10 and the surrounding structure, and the area where the remaining reinforcing ribs 12 are located is the circumferential reinforcing rib topology design area.

[0031] like Figure 3 The diagram shows the intention of a cylindrical thin-walled part forming a topological design region after removing the uniformly distributed annular reinforcing ribs 12. The inner skin 14 and outer skin 13 of the cylindrical thin-walled part 10 are extended outward along the skin thickness t direction, and the extension length is preferably 20% of the radius of the cylindrical thin-walled part. The space formed after this extension is the topological design region of the annular reinforcing ribs of the cylindrical thin-walled part 10.

[0032] Step S2: Establish topology design optimization constraints for the circumferential stiffeners of the cylindrical thin-walled part.

[0033] In this invention, the optimization constraints include volume fraction constraints, stress constraints, and manufacturability constraints, wherein:

[0034] (1) Establish volume fraction constraints, ensuring that the volume of the circumferential stiffeners of the cylindrical thin-walled part after topology design does not exceed 10% of the topology design domain;

[0035] (2) Establish stress constraints. After topology design, the stress level of the circumferential stiffener of the cylindrical thin-walled part shall not be greater than the allowable stress of the cylindrical thin-walled part material.

[0036] (3) Establish process constraints and after topology design, the circumferential stiffeners of the cylindrical thin-walled parts are directly connected to the skin.

[0037] After topology design, circumferential stiffeners of the cylindrical thin-walled part are constrained along the plane passing through the center point of the cylindrical thin-walled part.

[0038] Step S3: Establish the topology design target for the circumferential stiffeners of the cylindrical thin-walled part.

[0039] In this invention, maximizing the stiffness of the circumferential stiffeners of the cylindrical thin-walled parts is taken as the topology design objective.

[0040] Step S4: Apply pressure load and establish degree-of-freedom displacement constraints on the inner wall of the cylindrical thin-walled part according to the actual load condition of the cylindrical thin-walled part and the actual connection condition with the surrounding structure.

[0041] For example, in this embodiment of the invention, the two ends and the middle of the cylindrical thin-walled part are the connection points with the surrounding structure. Therefore, three-degree-of-freedom displacement constraints are established at the two ends and the middle of the outer side of the cylindrical thin-walled part to simulate its connection with the surrounding structure.

[0042] Step S5: Perform simulation analysis on the topology design of the circumferential stiffeners for the cylindrical thin-walled part to obtain the circumferential stiffener layout that satisfies the constraints of Step S2 and Step S3 to achieve the maximum stiffness.

[0043] By conducting topological simulation analysis of the circumferential stiffeners on a cylindrical thin-walled part, the circumferential stiffener layout that satisfies the constraints in steps 2 and 3 can be obtained. For example... Figure 4 The diagram shown is a topological simulation analysis result of the circumferential stiffeners of the cylindrical thin-walled part in this embodiment of the present invention. The stiffener layout scheme obtained based on the simulation analysis results is as follows: Figure 5 As shown.

[0044] Step S6: Perform a process check on the circumferential stiffeners of the cylindrical thin-walled part obtained in step S5. If the process requirements of the circumferential stiffener layout are not met, adjust the constraint symmetry plane and repeat steps S3 to S5 until the process requirements of the circumferential stiffener layout are met, and finally obtain the topology design scheme of the circumferential stiffeners of the cylindrical thin-walled part.

[0045] Combination Figure 5 and Figure 2 As shown, the weight of the reinforcing ribs in this invention is reduced by about 15% compared to the traditional uniformly distributed reinforcing rib layout.

[0046] Finally, the present invention also provides a cylindrical thin-walled part, which is obtained by the above-described cylindrical thin-walled part circumferential stiffener topology design method.

[0047] The topology design method for circumferential stiffeners of cylindrical thin-walled parts provided by the present invention can establish a circumferential stiffener layout scheme that is adapted to the load height of the cylindrical thin-walled parts. Compared with the traditional uniformly distributed annular stiffeners, the stiffener layout scheme obtained by the method of the present invention has a lower structural weight.

[0048] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A topological design method for circumferential stiffeners in a cylindrical thin-walled part, characterized in that, include: Step S1: Determine the topology design region of the circumferential stiffener of the cylindrical thin-walled part, and topologically design the skin of the cylindrical thin-walled part within the topology design region along the thickness direction to a predetermined thickness. The space formed by the predetermined thickness is the topology design domain of the circumferential stiffener of the cylindrical thin-walled part. Step S2: Establish topology design optimization constraints for the circumferential stiffeners of the cylindrical thin-walled part; Step S3: Establish the topology design target for the circumferential stiffeners of the cylindrical thin-walled part; Step S4: Apply pressure load and establish degree-of-freedom displacement constraints on the inner wall of the cylindrical thin-walled part according to the actual load condition of the cylindrical thin-walled part and the actual connection with the surrounding structure. Step S5: Perform simulation analysis on the topology design of the circumferential stiffeners for the cylindrical thin-walled part to obtain the circumferential stiffener layout that satisfies the constraints of Step S2 and Step S3 to achieve the maximum stiffness. Step S6: Perform a process check on the circumferential stiffeners of the cylindrical thin-walled part obtained in step S5. If the process requirements of the circumferential stiffener layout are not met, adjust the constraint symmetry plane and repeat steps S3 to S5 until the process requirements of the circumferential stiffener layout are met, and finally obtain the topology design scheme of the circumferential stiffeners of the cylindrical thin-walled part.

2. The topology design method for circumferential stiffeners of cylindrical thin-walled parts as described in claim 1, characterized in that, The predetermined thickness of the topology is 20% of the radius of the cylindrical thin-walled part.

3. The topology design method for circumferential stiffeners of cylindrical thin-walled parts as described in claim 1, characterized in that, The optimization constraints include volume fraction constraints, stress constraints, and manufacturability constraints, wherein: (1) The volume fraction constraint is that the volume of the circumferential stiffener of the cylindrical thin-walled part after topology design shall not exceed 10% of the topology design domain; (2) The stress constraint is that the stress level of the circumferential stiffener of the cylindrical thin-walled part after topology design is not greater than the allowable stress of the material of the cylindrical thin-walled part; (3) The process constraint is that the circumferential stiffeners of the cylindrical thin-walled parts are directly connected to the skin after the topology design.

4. The topology design method for circumferential stiffeners of cylindrical thin-walled parts as described in claim 1, characterized in that, The goal of the topology design is to maximize the stiffness of the circumferential stiffeners in the cylindrical thin-walled parts.

5. The topology design method for circumferential stiffeners of cylindrical thin-walled parts as described in claim 1, characterized in that, The constraint symmetry plane is a plane passing through the center point of the cylindrical thin-walled part.

6. A cylindrical thin-walled part, characterized in that, The cylindrical thin-walled part is obtained by the topological design method of circumferential stiffeners for cylindrical thin-walled parts as described in any one of claims 1 to 5.

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