A method for designing a structure parameter of an aircraft landing gear and body joint

Abstract

The application belongs to the technical field of structure parameter design of the joint between the aircraft landing gear and the aircraft body, and particularly relates to a structure parameter design method of the joint between the aircraft landing gear and the aircraft body, comprising the following steps: determining the structure optimization parameters of the joint between the aircraft landing gear and the aircraft body and their upper and lower limits; calculating the target mass of the joint between the aircraft landing gear and the aircraft body based on the structure optimization parameters; calculating the optimization strength margin of the joint between the aircraft landing gear and the aircraft body based on the structure optimization parameters; under the condition that the optimization strength margin is greater than the constraint strength margin, seeking the structure optimization parameters that minimize the target mass within the upper and lower limits of the structure optimization parameters as the structure design parameters; normalizing the structure design parameters to obtain the structure processing parameters of the joint between the aircraft landing gear and the aircraft body; calculating the final strength margin of the joint between the aircraft landing gear and the aircraft body based on the structure processing parameters, and re-normalizing the structure design parameters when the final strength margin is less than the constraint strength margin.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of structural parameter design of the joint between the landing gear and the fuselage of an aircraft, and particularly relates to a structural parameter design method of the joint between the landing gear and the fuselage of an aircraft. BACKGROUND

[0002] The joint between the landing gear and the fuselage of an aircraft mainly comprises a cylindrical support, a rotating shaft and a bushing, wherein one end of the cylindrical support is connected to a landing gear strut; one end of the rotating shaft extends into the other end of the cylindrical support, and the other end is connected to the fuselage; and the bushing is lined between the cylindrical supports.

[0003] The joint between the landing gear and the fuselage of an aircraft is subjected to complex loads, and in order to ensure that it can meet the strength requirements, each structural parameter is generally designed to be relatively conservative, resulting in a large overall volume and mass, which is inconsistent with the current demand for weight reduction of aircraft.

[0004] The present application is proposed in view of the existence of the above technical defects.

[0005] It should be noted that the disclosure of the above background art content is only used to assist in understanding the inventive concept and technical solutions of the present application, and it does not necessarily belong to the prior art of the present patent application. In the absence of explicit evidence that the above content has been disclosed on the filing date of the present application, the above background art should not be used to evaluate the novelty and inventiveness of the present application. SUMMARY

[0006] The purpose of the present application is to provide a structural parameter design method of the joint between the landing gear and the fuselage of an aircraft to overcome or alleviate at least one aspect of the known technical defects.

[0007] The technical solution of the present application is:

[0008] A structural parameter design method of the joint between the landing gear and the fuselage of an aircraft, comprising:

[0009] determining the structural optimization parameters of the joint between the landing gear and the fuselage of an aircraft and their upper and lower limits;

[0010] calculating the target mass of the joint between the landing gear and the fuselage of an aircraft based on the structural optimization parameters;

[0011] calculating the optimized strength margin of the joint between the landing gear and the fuselage of an aircraft based on the structural optimization parameters;

[0012] under the condition that the optimized strength margin is greater than the constraint strength margin, finding the structural optimization parameters that minimize the target mass within the range of the upper and lower limits of the structural optimization parameters as the structural design parameters;

[0013] normalizing the structural design parameters to obtain the structural processing parameters of the joint between the landing gear and the fuselage of an aircraft;

[0014] The final strength margin of the aircraft landing gear and fuselage joint is calculated based on the structural processing parameters, and when the final strength margin is less than the constraint strength margin, the structural design parameters are re-regularized.

[0015] According to at least one embodiment of the present application, in the aircraft landing gear and fuselage joint structure parameter design method described above, the structural optimization parameters include the outer diameter of the cylindrical support, the inner diameter of the cylindrical support, the length of the overlapping part between the cylindrical support and the rotating shaft, the force arm of the rotating shaft, the thickness of the bushing, and the inner diameter of the rotating shaft.

[0016] According to at least one embodiment of the present application, in the aircraft landing gear and fuselage joint structure parameter design method described above, the target mass of the aircraft landing gear and fuselage joint is calculated based on the structural optimization parameters, specifically:

[0017] m=m base +m axle ;

[0018]

[0019]

[0020] wherein,

[0021] m is the target mass of the aircraft landing gear and fuselage joint;

[0022] m base is the target mass of the cylindrical support;

[0023] m axle is the target mass of the rotating shaft;

[0024] n base is the mass amplification coefficient of the cylindrical support;

[0025] D1 is the outer diameter of the cylindrical support;

[0026] d1 is the inner diameter of the cylindrical support;

[0027] a is the length of the overlapping part between the cylindrical support and the rotating shaft;

[0028] ρ base is the material density of the cylindrical support;

[0029] n axle is the mass amplification coefficient of the rotating shaft;

[0030] t is the thickness of the bushing;

[0031] d2 is the inner diameter of the rotating shaft;

[0032] b is the force arm of the rotating shaft;

[0033] ρ axleThe material density of the rotating shaft.

[0034] According to at least one embodiment of the present application, in the above-mentioned aircraft landing gear and fuselage joint structure parameter design method, the optimized strength margin of the aircraft landing gear and fuselage joint is calculated based on the structure optimization parameters, including:

[0035] The optimized extrusion stress margin of the cylindrical support is calculated:

[0036]

[0037]

[0038]

[0039] Wherein,

[0040] M.S. 筒形支座挤压 The maximum optimized extrusion stress of the cylindrical support;

[0041] σ bru The extrusion strength limit of the cylindrical support material;

[0042] f 筒形支座挤压 The extrusion special coefficient of the cylindrical support;

[0043] σ br The maximum extrusion stress received by the cylindrical support;

[0044] q max The maximum linear load of the cylindrical support;

[0045] P is the maximum load received by the aircraft landing gear and fuselage joint;

[0046] The maximum optimized tensile stress margin of the cylindrical support is calculated:

[0047]

[0048]

[0049]

[0050] Wherein,

[0051] M.S. 筒形支座拉伸 The maximum optimized tensile stress of the cylindrical support;

[0052] K0 is the intermediate value in the calculation of the maximum optimized tensile stress of the cylindrical support;

[0053] σ b,筒形支座 The tensile strength limit of the cylindrical support material;

[0054] f 筒形支座拉伸Tensile special factor for cylindrical supports

[0055] σ t Maximum tensile stress experienced by cylindrical supports

[0056] Calculate maximum optimized bending stress margin for shafts:

[0057]

[0058]

[0059]

[0060]

[0061]

[0062] where,

[0063] M.S. 转轴弯曲 Maximum optimized bending stress for shafts

[0064] σ b,转轴 Tensile strength limit for shaft material

[0065] f 转轴弯曲 Bending special factor for shafts

[0066] σ max Maximum bending stress experienced by shafts

[0067] M max Maximum bending moment experienced by shafts

[0068] J y Bending moment of inertia for shaft cross-section

[0069] X A Intermediate value for maximum optimized bending stress calculation for shafts

[0070] Calculate maximum optimized shear stress margin for shafts:

[0071]

[0072]

[0073]

[0074] where,

[0075] M.S. 转轴剪切 Maximum optimized shear stress for shafts

[0076] τ bShear strength limit of the rotating shaft material;

[0077] f 转轴剪切 Shear special coefficient of the rotating shaft;

[0078] τ max Maximum shear force suffered by the rotating shaft;

[0079] S y Static moment of the rotating shaft. BRIEF DESCRIPTION OF DRAWINGS

[0080] Fig. 1 is a schematic diagram of a method for designing a structure parameter of a landing gear and a body joint of an airplane provided by an embodiment of the present application;

[0081] Fig. 2 is a schematic diagram of a landing gear and a body joint of an airplane provided by an embodiment of the present application.

[0082] In order to better illustrate the embodiments, some components in the drawings can be omitted, enlarged or reduced, and do not represent the actual product size. In addition, the drawings are only used for illustrative description and cannot be understood as a limitation of the patent. DETAILED DESCRIPTION

[0083] In order to make the technical solutions of the present application and its advantages clearer, the technical solutions of the present application will be further clearly and completely described below with reference to the drawings. It should be understood that the specific embodiments described herein are only part of the embodiments of the present application, and are only used to explain the present application, but not to limit the present application. It should be noted that, in order to facilitate description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the usual design. In the case of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined to obtain new embodiments.

[0084] In addition, unless otherwise defined, technical terms or scientific terms used in the description of the present application shall be understood as having the common meaning to those of ordinary skill in the art to which the present application belongs. The words "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer" and the like, which indicate the orientation in the description of the present application, are only used to indicate the relative directional or positional relationship, and not to imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and the relative positional relationship thereof can also be changed accordingly when the absolute position of the described object is changed, and therefore cannot be understood as a limitation on the present application. The "first", "second", "third" and the like used in the description of the present application are only for the purpose of description, in order to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "an" or "the" and the like used in the description of the present application should not be understood as an absolute limitation on the quantity, but should be understood as the presence of at least one. The "includes" or "contains" and the like used in the description of the present application means that the elements or objects appearing before the word are covered by the elements or objects listed after the word and their equivalents, and other elements or objects are not excluded.

[0085] In addition, it should be further pointed out that, unless otherwise explicitly specified and limited, the "installation", "connection", "connection" and the like used in the description of the present application should be understood in a broad sense, for example, the connection can be fixed connection, or detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements, and those skilled in the art can understand the specific meaning of the present application according to the specific circumstances.

[0086] The following will be described in detail in combination with the accompanying drawings Figs. 1-2 The present application will be further described in detail.

[0087] A method for designing the structure parameters of the joint between the landing gear and the body of an aircraft, comprising:

[0088] Determine the structure optimization parameters and their upper and lower limits of the joint between the landing gear and the body of an aircraft;

[0089] Calculate the target mass of the joint between the landing gear and the body of an aircraft based on the structure optimization parameters;

[0090] Calculate the optimized strength margin of the joint between the landing gear and the body of an aircraft based on the structure optimization parameters;

[0091] Under the condition that the optimized strength margin is greater than the constraint strength margin, find the structure optimization parameters that minimize the target mass within the upper and lower limits of the structure optimization parameters, as the structure design parameters;

[0092] The structural design parameters are normalized to obtain the structural processing parameters of the aircraft landing gear and fuselage joint, so as to facilitate the processing in engineering;

[0093] The final strength margin of the aircraft landing gear and fuselage joint is calculated based on the structural processing parameters, and when the final strength margin is less than the constraint strength margin, the structural design parameters are re-normalized.

[0094] For the aircraft landing gear and fuselage joint structural parameter design method disclosed in the above embodiments, those skilled in the art can understand that the design is to find the structural optimization parameters that minimize the target mass within the upper and lower limits of the structural optimization parameters under the condition that the optimized strength margin is greater than the constraint strength margin, as the structural design parameters, and the structural design parameters are normalized to obtain the structural processing parameters, and then the final strength margin of the aircraft landing gear and fuselage joint is calculated based on the structural processing parameters, and when the final strength margin is less than the constraint strength margin, the structural design parameters are re-normalized until the final strength margin is greater than the constraint strength margin. In this way, the design of the aircraft landing gear and fuselage joint structural parameters can be quickly and iteratively completed, which can ensure that the strength requirement is met while having a relatively small volume and mass.

[0095] In some optional embodiments, in the aircraft landing gear and fuselage joint structural parameter design method described above, the structural optimization parameters include the outer diameter D1 of the cylindrical support, the inner diameter d1 of the cylindrical support, the length a of the overlapping part between the cylindrical support and the rotating shaft, the force arm b of the rotating shaft, the thickness t of the bushing, and the inner diameter d2 of the rotating shaft.

[0096] In some optional embodiments, in the aircraft landing gear and fuselage joint structural parameter design method described above, the target mass of the aircraft landing gear and fuselage joint is calculated based on the structural optimization parameters, specifically:

[0097] m = m base + m axle ;

[0098]

[0099]

[0100] wherein,

[0101] m is the target mass of the aircraft landing gear and fuselage joint;

[0102] m base is the target mass of the cylindrical support;

[0103] m axle is the target mass of the rotating shaft;

[0104] n basemass amplification factor of the cylindrical support;

[0105] D1 is the outer diameter of the cylindrical support;

[0106] d1 is the inner diameter of the cylindrical support;

[0107] a is the length of the overlapping part between the cylindrical support and the rotating shaft;

[0108] ρ base is the material density of the cylindrical support;

[0109] n axle is the mass amplification factor of the rotating shaft;

[0110] t is the thickness of the bushing;

[0111] d2 is the inner diameter of the rotating shaft;

[0112] b is the force arm of the rotating shaft;

[0113] ρ axle is the material density of the rotating shaft.

[0114] In some optional embodiments, the above-mentioned method for designing the structure parameters of the aircraft landing gear and fuselage joint includes:

[0115] calculating the optimal extrusion stress margin of the cylindrical support:

[0116]

[0117]

[0118]

[0119] wherein,

[0120] M.S. 筒形支座挤压 is the maximum optimal extrusion stress of the cylindrical support;

[0121] σ bru is the extrusion strength limit of the cylindrical support material;

[0122] f 筒形支座挤压 is the extrusion special coefficient of the cylindrical support;

[0123] σ br is the maximum extrusion stress received by the cylindrical support;

[0124] q max is the maximum linear load of the cylindrical support;

[0125] P is the maximum load received by the aircraft landing gear and fuselage joint;

[0126] Maximum optimized tensile stress margin for a cylindrical support:

[0127]

[0128]

[0129]

[0130] wherein,

[0131] M.S. 筒形支座拉伸 is the maximum optimized tensile stress for the cylindrical support;

[0132] K0 is an intermediate value in the calculation of the maximum optimized tensile stress for the cylindrical support;

[0133] σ b,筒形支座 is the tensile strength limit of the material of the cylindrical support;

[0134] f 筒形支座拉伸 is the tensile special coefficient for the cylindrical support;

[0135] σ t is the maximum tensile stress to which the cylindrical support is subjected;

[0136] Maximum optimized bending stress margin for a rotating shaft:

[0137]

[0138]

[0139]

[0140]

[0141]

[0142] wherein,

[0143] M.S. 转轴弯曲 is the maximum optimized bending stress for the rotating shaft;

[0144] σ b,转轴 is the tensile strength limit of the material of the rotating shaft;

[0145] f 转轴弯曲 is the bending special coefficient for the rotating shaft;

[0146] σ max is the maximum bending stress to which the rotating shaft is subjected;

[0147] M max is the maximum bending moment to which the rotating shaft is subjected;

[0148] Jy is the bending inertia moment of the cross section of the rotating shaft;

[0149] X A is the intermediate value in the calculation of the maximum optimized bending stress of the rotating shaft;

[0150] calculating the maximum optimized shear stress margin of the rotating shaft:

[0151]

[0152]

[0153]

[0154] wherein,

[0155] M.S. 转轴剪切 is the maximum optimized shear stress of the rotating shaft;

[0156] τ b is the shear strength limit of the material of the rotating shaft;

[0157] f 转轴剪切 is the shear special coefficient of the rotating shaft;

[0158] τ max is the maximum shear force received by the rotating shaft;

[0159] S y is the static moment of the cross section of the rotating shaft.

[0160] The final strength margin of the aircraft landing gear and body interconnection joint based on the structural processing parameters can be calculated according to the above-mentioned optimized strength margin of the aircraft landing gear and body interconnection joint based on the structural optimization parameters, and will not be repeated here.

[0161] In one specific embodiment, the aircraft landing gear and body interconnection joint structural parameter design conditions of the aircraft landing gear and body interconnection joint are as follows:

[0162]

[0163]

[0164] The above-mentioned aircraft landing gear and body interconnection joint structural parameter design method is used for design, and the comparison results are as follows:

[0165]

[0166] From the above, it can be seen that the structure processing parameters obtained by using the parameter design method of the joint structure between the aircraft landing gear and the aircraft body disclosed in the above embodiments can reduce the mass of the joint between the aircraft landing gear and the aircraft body from 13.11 to 11.01 under the condition of ensuring the strength, which is beneficial to weight reduction of the aircraft.

[0167] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be mutually referred to.

[0168] So far, the technical solution of the present application has been described in combination with the preferred embodiments shown in the drawings. It should be understood by those skilled in the art that the protection scope of the present application is obviously not limited to these specific embodiments. Without deviating from the principles of the present application, those skilled in the art can make equivalent changes or replacements to the related technical features. The technical solutions after the changes or replacements will fall within the protection scope of the present application.

Claims

1. A method for designing the structural parameters of the joint between an aircraft landing gear and fuselage, characterized in that, include: Determine the structural optimization parameters and their upper and lower limits for the joint between the aircraft landing gear and the fuselage; Calculate the target mass of the joint between the aircraft landing gear and the fuselage based on structural optimization parameters; Calculate the optimized strength margin of the joint between the aircraft landing gear and the fuselage based on structural optimization parameters; Under the condition that the optimization strength margin is greater than the constraint strength margin, within the upper and lower limits of the structural optimization parameters, find the structural optimization parameters that minimize the target mass and use them as structural design parameters. By regularizing the structural design parameters, the structural machining parameters of the joint between the aircraft landing gear and the fuselage are obtained; The final strength margin of the joint between the aircraft landing gear and the fuselage is calculated based on the structural processing parameters. If the final strength margin is less than the constraint strength margin, the structural design parameters are readjusted. The target mass of the junction between the aircraft landing gear and the fuselage is calculated based on structural optimization parameters, specifically: ； ； ； in, The target mass of the joint between the aircraft landing gear and the fuselage; The target mass for the cylindrical support; The target mass of the shaft; This is the mass amplification factor for the cylindrical support; The outer diameter of the cylindrical support; The inner diameter of the cylindrical support; This is the length of the overlapping portion between the cylindrical support and the rotating shaft; The material density of the cylindrical support; This is the mass amplification factor of the shaft; The thickness of the bushing; The inner diameter of the shaft; The lever arm of the pivot; The density of the material of the shaft; The optimized strength margin of the joint between the aircraft landing gear and the fuselage, calculated based on structural optimization parameters, includes: Calculate the optimal compressive stress margin for the cylindrical support: ； ； ； in, To achieve the maximum optimized compressive stress for the cylindrical support; The ultimate compressive strength of the cylindrical support material; This refers to the compression coefficient of the cylindrical support; This represents the maximum compressive stress experienced by the cylindrical support. This represents the maximum line load on the cylindrical support. This is the maximum load on the joint between the aircraft landing gear and the fuselage. Calculate the maximum optimized tensile stress margin for the cylindrical support: ； ； ； in, To achieve the maximum optimized tensile stress for the cylindrical support; Intermediate values ​​were calculated for the maximum optimized tensile stress of the cylindrical support. The tensile strength limit of the cylindrical support material; For the tensile special coefficient of the cylindrical support; This represents the maximum tensile stress experienced by the cylindrical support. Calculate the maximum optimized bending stress margin of the shaft: ； ； ； ； ( )； in, To optimize the bending stress of the shaft; The tensile strength limit of the shaft material; This is a special coefficient for the bending of the shaft; This represents the maximum bending stress experienced by the shaft. This represents the maximum bending moment experienced by the shaft. The bending moment of inertia of the cross section of the axis of rotation; Intermediate values ​​were calculated for the maximum optimized bending stress of the shaft. Calculate the maximum optimized shear stress margin of the shaft: ； ； ( )； in, To optimize the maximum shear stress of the shaft; The shear strength limit of the shaft material; This is the shear coefficient for the rotating shaft; This represents the maximum shear force experienced by the shaft. Let be the static moment of the cross section of the shaft.

2. The method for designing the structural parameters of the interlocking structure between the aircraft landing gear and the fuselage according to claim 1, characterized in that, The structural optimization parameters include the outer diameter of the cylindrical support, the inner diameter of the cylindrical support, the length of the overlap between the cylindrical support and the rotating shaft, the lever arm of the rotating shaft, the thickness of the bushing, and the inner diameter of the rotating shaft.

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