Structure and fatigue load design method of aircraft wheel hub with hot-melt plug holes

Abstract

The present invention provides a structure with a heat-melt plug hole in an aircraft wheel hub and a fatigue load design method, belonging to the technical field of aircraft brake wheels. The heat-melt plug hole in the aircraft wheel hub is an L-shaped structure with a connection hole on the short side for securing the structure to the clamping fixture of an electronic universal testing machine, and a heat-melt plug hole on the long side. The present invention proposes a structure with a heat-melt plug hole in an aircraft wheel hub. This structure can replace a complete wheel hub in fatigue testing to assess whether the fatigue life of the heat-melt plug hole in the structural weak point meets the test requirements. The fatigue load design method provided by the present invention can avoid the need for extensive fatigue testing of complete wheel hubs, saving testing time and cost. Simulation and test results show that the fatigue life of the wheel hub estimated using this method is within 10% error.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft brake wheels, and in particular relates to a structure with a hot-melt plug hole in an aircraft wheel hub and a fatigue load design method. Background Art

[0002] As a critical load-bearing component of an aircraft, the strength of its wheel hub is directly related to the aircraft's safety and performance. Data indicates that fatigue failure is currently one of the primary causes of structural failure in aircraft wheels. With the increasing lightweighting, economy, and frequent use of modern aircraft, the fatigue problem of aircraft hubs has become increasingly prominent, and hub fatigue life has become a key assessment indicator for aircraft hub design.

[0003] During the rolling process of aircraft wheels, the load forms change alternately. During the early design process, fatigue issues cannot be ignored. However, aircraft wheels are heavy, expensive, and have a long lifespan. The fatigue load design method that uses physical objects for test verification requires long-term use of the fatigue test bench, and the test verification cycle is at least one year, which is costly. Summary of the Invention

[0004] In order to solve the problems of long fatigue verification cycle and high physical verification cost in the existing fatigue load design method using physical objects for test verification, the present invention proposes a structure with a hot-melt plug hole in the aircraft wheel hub and a fatigue load design method. The technical solution is as follows:

[0005] In a first aspect, a structure is provided with a hot-melt plug hole in the hub of an aircraft wheel. The hot-melt plug hole in the hub of an aircraft wheel is an L-shaped structure. A connecting hole is provided on the short side of the structure for fixing the structure on the clamping fixture of an electronic universal testing machine, and a hot-melt plug hole is provided on the long side.

[0006] The connecting holes on the short sides are threaded holes.

[0007] Among them, the connection between the short side and the long side adopts arc transition.

[0008] Among them, the arc transition size is R=10mm.

[0009] The diameter of the hot melt plug hole is 8mm to 13mm.

[0010] In a second aspect, a fatigue load design method is provided using a structure having a hot-melt plug hole in an aircraft wheel hub according to any one of the first aspects, the method comprising:

[0011] Step 1: Determine the material used for the aircraft wheel hub;

[0012] Step 2: Determine the median fatigue stress σ of the material used for the aircraft wheel hub;

[0013] Step 3: establishing a simulation analysis model of a structure with a hot-melt plug hole in an aircraft wheel hub;

[0014] Step 4, reversely calculate the loading force F of the structure with the hot-melt plug hole in the aircraft wheel hub when the stress is σ1=σ;

[0015] Step 5: Determine the life N of the structure provided with the hot-melt plug hole in the aircraft wheel hub, and compare the life N with the designed life requirement value T;

[0016] Step 6: If T≥N, it is determined that the wheel hub hot melt plugging hole does not meet the service life requirement; if T<N, it is determined that the wheel hub hot melt plugging hole meets the service life requirement.

[0017] The process of establishing a simulation analysis model for a structure with a hot-melt plug hole in an aircraft wheel hub includes:

[0018] Establish a 3D simulation model of a structure with hot-melt plug holes in the hub of an aircraft wheel;

[0019] Meshing the obtained three-dimensional simulation model;

[0020] Obtaining a simulation analysis model of a structure having a hot-melt plug hole in an aircraft wheel hub;

[0021] The parameters of the part material in the three-dimensional simulation model are defined, and the parameters include elastic modulus and Poisson's ratio.

[0022] In step 2, when Kt=1 and R=0.1, 10 7 Median fatigue stress σ corresponding to the number of cycles.

[0023] Among them, in step 5, on an electronic universal testing machine, a fatigue test is performed on a typical part of the hot melt plug hole using a tooling clamp, the test stress ratio R is 0.1, and a loading force F is applied. The loading frequency is determined according to the electronic universal testing machine, and the number of cycles obtained by the test is N.

[0024] The beneficial effects of the present invention are:

[0025] The present invention proposes a structure with hot-melt plug holes in an aircraft wheel hub. This structure replaces the complete wheel hub in fatigue testing to evaluate whether the fatigue life of the hot-melt plug holes in the weak parts of the structure meets the test requirements. The fatigue load design method provided by the present invention can avoid the need to use a large number of complete hubs for fatigue testing, saving test time and test costs. Simulation and test results show that the error in evaluating the fatigue life of the wheel hub using this method is within 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1This is a schematic diagram of a hub structure in the related art;

[0027] Figure 2 It is the left view of the hub structure;

[0028] Figure 3 This is a cross-sectional view of a structure provided with a hot-melt plug hole in an aircraft wheel hub according to an embodiment of the present invention;

[0029] Figure 4 It is a top view of a structure provided with a hot-melt plug hole in an aircraft wheel hub provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below through specific implementation methods and drawings.

[0031] like Figure 1 As shown, the aircraft wheel hub 1 is the main load-bearing component of the brake main wheel. Hot melt plug holes 2 are evenly designed in the low stress areas of the hub wall. The hot melt plug holes 2 are generally 8mm-13mm in diameter. The hub wall is generally less than 10mm thick. However, the wall width is generally more than 200mm. The hot melt plug holes are necessary openings in weak areas, which can easily cause stress concentration or insufficient fatigue strength.

[0032] The present invention provides a structure with a hot-melt plug hole in the hub of an aircraft wheel, such as Figure 2 、 Figure 3 and Figure 4 As shown, the aircraft wheel hub heat-insulated hole is an L-shaped structure. The short side of the structure has a threaded hole for fixing it to the clamping fixture of the electronic universal testing machine. The long side has a heat-insulated hole. The connection between the short and long sides uses an arc transition with an R=10mm radius to avoid stress concentration. The weak point of the structure is designed at the heat-insulated hole. The diameter of the heat-insulated hole ranges from 8mm to 13mm.

[0033] The present invention proposes a fatigue load design method using a structure provided with a hot-melt plug hole in an aircraft wheel hub, the method specifically comprising the following steps:

[0034] Step 1: Determine the material used for the aircraft wheel hub;

[0035] Step 2: determining the median fatigue stress of the material used for the aircraft wheel hub;

[0036] By consulting the Aviation Materials Handbook, we can obtain the SN curve of the aircraft wheel hub and find the curve where Kt = 1, R = 0.1, 10 7 Median fatigue stress σ corresponding to the number of cycles.

[0037] Step 3: Using ABAQUS finite element analysis software to establish a simulation analysis model of a structure with a hot-melt plug hole in an aircraft wheel hub;

[0038] In one achievable embodiment, the process of establishing a simulation analysis model of a structure having a hot-melt plug hole in an aircraft wheel hub specifically includes:

[0039] 1. Establish a three-dimensional simulation model of a structure with hot-melt plug holes in the hub of an aircraft wheel.

[0040] 2. Divide the obtained 3D simulation model into grids, defining the size of each grid as 1×1 mm.

[0041] 3. Obtain a simulation analysis model of a structure with a hot-melt plug hole in an aircraft wheel hub.

[0042] 4. Define the parameters of the part material in the three-dimensional simulation model, including elastic modulus and Poisson's ratio.

[0043] In the present invention, the structure provided with the hot-melt plug hole in the hub of the aircraft wheel is made of aluminum alloy material, and the input parameters include: the elastic modulus E1 and the Poisson's ratio u1 of the aluminum alloy.

[0044] Step 4: Using ABAQUS finite element analysis software, inversely calculate the loading force F of the structure with the hot-melt plug hole in the aircraft wheel hub when the stress is σ1 = σ;

[0045] Apply a loading force F to a structure with a hot-melt plug hole in an aircraft wheel hub to obtain the corresponding stress σ1. Taking σ1=σ as a reference, the loading force F when σ1=σ is obtained by reverse calculation.

[0046] Step 5: Determine the life N of the structure provided with the hot-melt plug hole in the aircraft wheel hub, and compare the life N with the designed life requirement value T.

[0047] On an electronic universal testing machine, a tooling is used to clamp a typical part of the hot melt plug hole for fatigue testing. The test stress ratio R is 0.1, and a loading force F is applied. The loading frequency is determined according to the electronic universal testing machine, and the number of cycles obtained in the test is N.

[0048] Step 6: If T≥N, it is determined that the wheel hub hot melt plugging hole does not meet the service life requirement; if T<N, it is determined that the wheel hub hot melt plugging hole meets the service life requirement.

[0049] For example, the present invention proposes a fatigue load design method using a structure with a hot-melt plug hole in an aircraft wheel hub, which may specifically include the following steps:

[0050] Step 1: Determine the material used for the aircraft wheel hub;

[0051] In this embodiment, the material used for the aircraft wheel hub is 7055.

[0052] Step 2: determining the median fatigue stress of the material used for the aircraft wheel hub;

[0053] Query the Aviation Materials Handbook to obtain the SN curve of the aircraft wheel hub. When Kt=1,R=0.1,10 7 Median fatigue stress σ corresponding to the number of cycles.

[0054] In this embodiment, 7055 aluminum alloy 10 7 The median fatigue stress corresponding to the number of cycles is σ = 296 MPa.

[0055] Step 3: Using ABAQUS finite element analysis software to establish a simulation analysis model of a structure with a hot-melt plug hole in an aircraft wheel hub;

[0056] 1. Establish a three-dimensional simulation model of a structure with a hot-melt plug hole in an aircraft wheel hub. 2. Mesh the resulting three-dimensional simulation model. Define the size of each mesh as 1×1 mm. 3. Obtain a simulation analysis model of the structure with a hot-melt plug hole in an aircraft wheel hub. 4. Define the parameters of the component materials in the three-dimensional simulation model, including the elastic modulus and Poisson's ratio. In the present invention, the structure with the hot-melt plug hole in the aircraft wheel hub is made of 7055 aluminum alloy. The input parameters include the elastic modulus E1 and Poisson's ratio u1 of the 7055 aluminum alloy.

[0057] In this embodiment:

[0058] E1=69GPa;u1=0.3.

[0059] Step 4: Using ABAQUS finite element analysis software, inversely calculate the loading force F of the structure with the hot-melt plug hole in the aircraft wheel hub when the stress is σ1 = σ = 296 MPa;

[0060] A loading force F is applied to a structure with a hot-melt plug hole in an aircraft wheel hub to obtain the corresponding stress σ1. Taking σ1=σ=296 MPa as a reference, the loading force F when σ1=σ=296 MPa is obtained by reverse calculation.

[0061] In this embodiment, F=6100N.

[0062] Step 5: Determine the life N of the structure provided with the hot-melt plug hole in the aircraft wheel hub, and compare the life N with the designed life requirement value T.

[0063] On an electronic universal testing machine, a tooling is used to clamp a typical part of the hot melt plug hole for fatigue testing. The test stress ratio R is 0.1, and a loading force F is applied. The loading frequency is determined according to the electronic universal testing machine, and the number of cycles obtained in the test is N.

[0064] Step 6: If T≥N, the wheel hub hot-melt plugging hole does not meet the service life requirement; if T<N, the wheel hub hot-melt plugging hole meets the service life requirement.

[0065] For example, the present invention proposes a fatigue load design method using a structure with a hot-melt plug hole in an aircraft wheel hub, which may specifically include the following steps:

[0066] Step 1: Determine the material used for the aircraft wheel hub;

[0067] In this embodiment, the material used for the aircraft wheel hub is 2A14.

[0068] Step 2: determining the median fatigue stress of the material used for the aircraft wheel hub;

[0069] Query the Aviation Materials Handbook to obtain the SN curve of the aircraft wheel hub. When Kt=1,R=0.1,10 7 Median fatigue stress σ corresponding to the number of cycles.

[0070] In this embodiment, 2A14 aluminum alloy 10 7 The median fatigue stress corresponding to the number of cycles is σ = 155 MPa.

[0071] Step 3: Using ABAQUS finite element analysis software to establish a simulation analysis model of a structure with a hot-melt plug hole in an aircraft wheel hub;

[0072] 1. Establish a three-dimensional simulation model of a structure with a hot-melt plug hole in an aircraft wheel hub. 2. Mesh the resulting three-dimensional simulation model. Define the size of each mesh as 1×1 mm. 3. Obtain a simulation analysis model of the structure with a hot-melt plug hole in an aircraft wheel hub. 4. Define the parameters of the component materials in the three-dimensional simulation model, including the elastic modulus and Poisson's ratio. In the present invention, the structure with the hot-melt plug hole in the aircraft wheel hub is made of 2A14 aluminum alloy. The input parameters include the elastic modulus E1 and Poisson's ratio u1 of the 2A14 aluminum alloy.

[0073] In this embodiment:

[0074] E1=71GPa;u1=0.33.

[0075] Step 4: Using ABAQUS finite element analysis software, inversely calculate the loading force F of the structure with the hot-melt plug hole in the aircraft wheel hub when the stress is σ1 = σ = 155 MPa;

[0076] A loading force F is applied to a structure with a hot-melt plug hole in an aircraft wheel hub to obtain the corresponding stress σ1. Taking σ1=σ=155 MPa as a reference, the loading force F when σ1=σ=155 MPa is obtained by reverse calculation.

[0077] In this embodiment, F=2900N.

[0078] Step 5: Determine the life N of the structure provided with the hot-melt plug hole in the aircraft wheel hub, and compare the life N with the designed life requirement value T.

[0079] On an electronic universal testing machine, a tooling is used to clamp a typical part of the hot melt plug hole for fatigue testing. The test stress ratio R is 0.1, and a loading force F is applied. The loading frequency is determined according to the electronic universal testing machine, and the number of cycles obtained in the test is N.

[0080] Step 6: If T≥N, the wheel hub hot-melt plugging hole does not meet the service life requirement; if T<N, the wheel hub hot-melt plugging hole meets the service life requirement.

[0081] The above merely describes the embodiments of the present invention, and while the description is relatively specific and detailed, it should not be construed as limiting the scope of the invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Furthermore, any portions not described in detail herein are conventional techniques.

Claims

1. A fatigue load design method using a structure with a hot-melt plug hole in an aircraft wheel hub, characterized in that: The aircraft wheel hub hot-melt plug hole is an L-shaped structure. The short side of the structure is provided with a connection hole for fixing the structure to the clamping fixture of the electronic universal testing machine, and the long side is provided with a hot-melt plug hole. The connection hole on the short side is a threaded hole. The connection between the short side and the long side adopts an arc transition. The arc transition size is R = 10mm. The diameter of the hot-melt plug hole is 8mm to 13mm. The method includes: Step 1: Determine the material used for the aircraft wheel hub; Step 2: Determine the median fatigue stress σ of the material used for the aircraft wheel hub, and find the median fatigue stress σ corresponding to 10 7 cycles when Kt=1 and R=0.1 from the previously obtained aircraft wheel hub SN curve; Step 3: Establishing a simulation analysis model of a structure having a hot-melt plug hole in an aircraft wheel hub: Establishing a three-dimensional simulation model of the structure having a hot-melt plug hole in an aircraft wheel hub; Meshing the obtained three-dimensional simulation model; Obtaining a simulation analysis model of the structure having a hot-melt plug hole in an aircraft wheel hub; Defining parameters of part materials in the three-dimensional simulation model, including elastic modulus and Poisson's ratio; Step 4, reversely calculate the loading force F of the structure with the hot-melt plug hole in the aircraft wheel hub when the stress is σ1=σ; Step 5: Determine the life N of the structure having the hot-melt plug hole in the aircraft wheel hub, and compare the life N with the design life requirement value T: A fatigue test is conducted on an electronic universal testing machine using a fixture to clamp a typical location of the hot-melt plug hole. The test stress ratio R is 0.1, and a loading force F is applied. The loading frequency is determined by the electronic universal testing machine. The number of cycles obtained in the test is N. Step 6: If T≥N, it is determined that the wheel hub hot melt plugging hole does not meet the service life requirement; if T<N, it is determined that the wheel hub hot melt plugging hole meets the service life requirement.

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