Anti-fatigue-design hot melting plug hole structure for aviation aircraft wheel and design method of anti-fatigue-design hot melting plug hole structure

Abstract

The invention relates to the technical field of aviation design, in particular to an anti-fatigue design hot melting plug hole structure for an aviation airplane wheel and a design method thereof, and the method comprises the following steps: acquiring an overlapping area of a low-stress area and a high-temperature area relative to the position of a hub when a hole is not formed; a plurality of hot melting plugs of different specifications are evenly arranged on the overlapped area along the circumference of the hub cylinder wall, and the number of holes in the hub cylinder wall, the diameters of the holes and the positions of the holes are obtained; whether the service life requirement is met or not under the hub tapping condition is evaluated through finite elements; and according to the number of the hot melting plugs meeting the service life requirement, the final number of the open holes, the diameters of the open holes and the positions of the open holes are determined. According to the hot-melting plug hole structure of the aviation aircraft wheel, the service life of the hub is greatly prolonged, the reliability of the hub is greatly improved, and stress concentration at the hot-melting plug hole of the hub of the aviation aircraft wheel is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation design, and in particular to a heat-melt plug hole structure for an aircraft wheel with an anti-fatigue design and a design method thereof. Background Art

[0002] With the continuous advancement of aviation technology, the load and life requirements for aircraft wheels have become more stringent. During taxiing, the braking system generates a large amount of heat, which is conducted outward through the wheel assembly. The wheel assembly is also a critical load-bearing structural component of the aircraft, and its load-bearing and fatigue performance directly impacts the aircraft's safety and lifespan. The hot-melt plug hole is a key structure on aircraft wheels, used to install a hot-melt plug. The hot-melt plug is installed on tubeless aircraft wheels to prevent overheating and tire blowouts during braking. Made of a low-melting alloy material with a specific melting point, the hot-melt plug melts when the wheel assembly temperature exceeds this melting point, releasing the pressure inside the tire. This prevents dangerous accidents such as tire blowouts caused by excessive tire pressure, thereby ensuring aircraft safety.

[0003] At present, the hot melt plugs used in domestic aircraft wheels are mainly threaded, which requires threaded holes to be drilled on the thin wall of the wheel hub for installation. Figure 1 As shown, the hot melt plug and the hub hot melt plug hole structure assembly diagram, wherein the hot melt plug 1 is set in the hub hot melt plug hole 1, and the hot melt plug sleeve is provided with a sealing ring 3, see Figure 2 Figure 2 shows a schematic diagram of a half-section of a threaded hot melt plug. Since the wheel hub is the primary load-bearing component, the hot melt plug requires a hole in the hub wall. The structural strength of the hole is relatively low compared to other areas, so the hole should be drilled in a low-stress area. Furthermore, during operation, wheels are subject to heavy, alternating loads under various operating conditions for extended periods. Because the hole is relatively weak, the small thread roots of the threaded hole create stress concentrations. This stress concentration accelerates fatigue growth and shortens the fatigue life of the wheel structure. Especially under alternating loads, stress concentration areas are the initiation sites of fatigue cracks. Fatigue life testing of various wheel models has revealed fatigue cracks caused by the hot melt plug's thread points, seriously impacting product life assessment and development progress. Furthermore, threaded hot melt plugs require in-and-out tightening during assembly and disassembly, making them inconvenient, impacting ground crew maintenance and replacement time, and reducing aircraft re-deployment efficiency.

[0004] As a new structural form, the push-in hot melt plug does not require threaded holes on the thin wall of the wheel hub and can be directly pushed in for installation. This structure can eliminate factors such as threads that may cause original cracks, greatly improving the life and reliability of the wheel hub and reducing stress concentration at the hot melt plug hole of the aircraft wheel hub.

[0005] The prior art discloses a wheel with a heat-insulating plug, comprising a hub, a tire, and the heat-insulating plug. The hub comprises a hub arm and a hub web, with the tire mounted on the hub arm. A threaded hole is provided at the junction of the hub arm and the hub web, with the heat-insulating plug mating with the threaded hole. The bottom of the threaded hole has a through-hole that connects to the interior of the tire. The heat-insulating plug comprises a low-melting core and a shell, with the low-melting core located within the shell, which has threads that mate with the threaded hole. This heat-insulating plug requires machining matching threads on the hub wall. The sharp points of the threads create stress concentrations that can cause fatigue cracks. The prior art also discloses a push-in heat-insulating plug for aircraft wheels, but lacks a design method for the corresponding heat-insulating plug hole. An analysis of existing heat-insulating plugs only describes the structures of threaded and push-in heat-insulating plugs, without developing an effective design method for the corresponding heat-insulating plug holes. This provides little guidance for the design of heat-insulating plug holes and the selection of heat-insulating plugs for aircraft products. Summary of the Invention

[0006] The present invention eliminates factors such as threads that can cause initial cracks, reduces stress concentration at the hub's hot-melt plug hole, and overcomes the shortcomings of existing threaded hot-melt plug structures. This addresses the current situation where thin-walled hubs with threaded holes reduce aircraft wheel strength and service life, as well as the lack of support for hot-melt plug hole designs. The present invention provides a fatigue-resistant hot-melt plug hole structure for aircraft wheels and a design method for the same. This method, based on a fatigue-resistant, threadless hot-melt plug hole structure for aircraft wheels, eliminates factors such as threads that can cause initial cracks, significantly improving the life and reliability of the wheel hub and reducing stress concentration at the hub's hot-melt plug hole.

[0007] The first object of the present invention is to provide a method for designing a heat-melt plug hole structure for an aircraft wheel with a fatigue-resistant design, comprising:

[0008] Obtain the low stress area of ​​the hub wall in the wheel assembly under design load when no hole is opened;

[0009] According to the high temperature area of ​​the brake disc during braking, the position of the high temperature area relative to the wheel hub is obtained;

[0010] Obtain the overlap area based on the low stress area and the high temperature area relative to the hub;

[0011] Multiple heat-insulating plugs of different specifications are evenly arranged along the circumference of the hub wall in the overlapping area. Through simulation analysis, the minimum stress of the hub wall for each specification is determined, and the number, diameter, and location of the openings on the hub wall are obtained.

[0012] Based on the number and diameter of the holes on the wheel hub wall, finite element analysis is used to evaluate whether the wheel hub meets the life requirements when the holes are opened.

[0013] The final number of openings, the diameter of the openings, and the locations of the openings are determined based on the number of thermal plugs that meet the life requirements.

[0014] Preferably, the low stress area is an area where the MISES stress is lower than 60% of the yield strength under the design load, and serves as a preliminary arrangement position of the thermal plug, wherein the position tolerance is 5% to the left and right of the axial extension.

[0015] Preferably, the overlap area is an arithmetic average of the positions of the low stress area and the high temperature area relative to the position of the hub.

[0016] Preferably, hot melt plug holes with a diameter of 6 to 10 mm are evenly arranged along the circumference of the hub wall in the overlapping area, and finite element simulation analysis is used to determine the minimum stress of the hub wall under each specification. If the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength, the design requirements are met; otherwise, the number of axially arranged hot melt plugs is reduced in sequence, by 2 at a time according to the gradient, and the minimum stress of the hub wall with hot melt plug holes with a diameter of 6 to 10 mm evenly arranged in the axial direction of the hub wall is calculated respectively, until the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength.

[0017] Preferably, meeting the life requirement means that the stress at the opening should not exceed 1.1 times the fatigue limit of the hub material.

[0018] Preferably, the method further comprises determining the low-melting alloy diameter of the thermal plug according to the final number and diameter of the openings, as well as the positions of the openings, based on the requirement of meeting complete degassing.

[0019] A second object of the present invention is to provide a theoretical verification method for a heat-melt plugging hole for an aircraft wheel with an anti-fatigue design, comprising:

[0020] Obtain the load generated by aircraft wheels under inflation pressure;

[0021] Based on the load generated by the inflation pressure, the tensile stress under the inflation load and the tensile stress under the simultaneous action of the lateral load and inflation load on a single aircraft wheel are obtained;

[0022] Obtain stress amplitude and average stress based on the tensile stress under inflation load and the tensile stress under the simultaneous action of lateral load and inflation load on a single aircraft wheel;

[0023] Obtain the number of fatigue cycles based on stress amplitude and mean stress;

[0024] The number of fatigue cycles is used to determine whether the hot melt plug hole structure design meets the service life requirements.

[0025] Preferably, the number of fatigue cycles is obtained according to the following steps:

[0026] Obtain the equivalent stress amplitude based on the stress amplitude and the average stress;

[0027] Obtain the number of fatigue cycles based on the equivalent stress amplitude.

[0028] Preferably, judging whether the hot melt plug hole structure design meets the service life requirement according to the number of fatigue cycles includes: judging that if the number of fatigue cycles is greater than the service life requirement, the hot melt plug hole structure design meets the service life requirement.

[0029] The third object of the present invention is to provide a heat-melt plugging structure for aircraft wheels with an anti-fatigue design.

[0030] The present invention has at least the following beneficial effects:

[0031] The present invention provides a hot-melt plug hole structure for an aircraft wheel with an anti-fatigue design and a design method thereof. The hot-melt plug hole structure designed by this method can effectively improve the service life of the wheel. The existing mature hot-melt plug holes are threaded hole structures, and their small thread tooth bottoms are stress concentration structures, which are more prone to stress concentration, affecting the fatigue life of the structure, and the threads need to be protected from damage during use. The hot-melt plug hole structure for an aircraft wheel with a threadless structure and anti-fatigue design proposed by the present invention eliminates factors such as threads that may cause original cracks, greatly improves the life and reliability of the wheel hub, and reduces stress concentration at the hot-melt plug hole of the aircraft wheel hub.

[0032] The present invention proposes a fatigue-resistant hot-melt plug hole structure for aircraft wheels and a design method thereof, that is, a design and selection method for the arrangement position, number and size of the hot-melt plug holes is proposed. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of the assembly of the thermal plug and the wheel hub thermal plug hole structure;

[0034] Figure 2 This is a schematic diagram of the half-section structure of a threaded thermal plug;

[0035] Figure 3 This is a schematic diagram of the finite element calculation results of the non-hole wheel hub of the present invention;

[0036] Figure 4 This is a schematic diagram of the high-temperature area of ​​the brake disc;

[0037] Figure 5 Schematic diagram of fatigue life at the opening;

[0038] Figure 6 The invention proposes a heat-melt plugging structure for aircraft wheels with an anti-fatigue design;

[0039] Figure 7This is a diagram showing the coordination between the hot melt plug hole and the hot melt plug proposed in the present invention;

[0040] Figure 8 This is a schematic diagram of the preliminary arrangement of the thermal plug proposed in the present invention;

[0041] Figure 9 A schematic diagram of the location of the hot melt plug hole designed for the present invention;

[0042] In the figure: 1. Wheel hub hot melt plug hole; 2. Hot melt plug; 3. Sealing ring; 4. Fixed wheel rim; 5. Movable wheel rim; 6. Hot melt plug hole. DETAILED DESCRIPTION

[0043] In order to illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description with reference to the embodiments.

[0044] The purpose of the present invention is to eliminate factors such as threads that may cause original cracks, reduce stress concentration at the hub hot-melt plug hole, overcome the shortcomings of the existing threaded hot-melt plug structure, and solve the current situation where the strength and service life of aircraft wheels are reduced due to threaded holes in thin-walled hubs, as well as insufficient support for the hot-melt plug hole design. The present invention proposes a design method for hot-melt plug holes for aircraft wheels with an anti-fatigue design.

[0045] To achieve the above objectives, a method for designing a fatigue-resistant hot-melt plug hole structure for an aircraft wheel is provided, comprising:

[0046] S1. Obtaining a low stress area of ​​the hub wall of the wheel assembly under a design load when no hole is drilled;

[0047] The low stress area is an area where the MISES stress is lower than 60% of the yield strength under the design load and serves as a preliminary placement position for the thermal plug, wherein the position tolerance is 5% to the left and right of the axial extension.

[0048] S2. Obtaining a position of the high-temperature area of ​​the brake disc relative to the wheel hub according to the high-temperature area of ​​the brake disc during braking;

[0049] S3. Obtaining an overlap area based on the positions of the low stress area and the high temperature area relative to the wheel hub;

[0050] The overlap area is the arithmetic average of the positions of the low stress area and the high temperature area relative to the position of the hub.

[0051] S4. Evenly arrange multiple hot melt plugs of different specifications along the circumference of the wheel hub wall in the overlapping area. Determine the minimum stress of the wheel hub wall for each specification through simulation analysis, and obtain the number, diameter, and location of the openings on the wheel hub wall.

[0052] In the overlapping area, hot melt plug holes with a diameter of 6 to 10 mm are evenly arranged along the circumference of the hub wall. Finite element simulation analysis is used to determine the minimum stress of the hub wall for each specification. If the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength, the design requirements are met; otherwise, the number of axially arranged hot melt plugs is reduced in sequence, by 2 at a time according to the gradient, and the minimum stress of the hub wall with hot melt plug holes with a diameter of 6 to 10 mm evenly arranged in the axial direction of the hub wall is calculated respectively until the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength.

[0053] S5. Based on the number and diameter of the holes on the wheel hub wall, use finite element analysis to evaluate whether the wheel hub meets the life requirements when the holes are opened.

[0054] The final number of openings, the diameter of the openings, and the locations of the openings are determined based on the number of thermal plugs that meet the life requirements.

[0055] Meeting the life requirements means that the stress at the opening should not exceed 1.1 times the fatigue limit of the hub material.

[0056] The present invention also includes determining the diameter of the low-melting alloy of the thermal plug based on the final number and diameter of the openings, as well as the location of the openings, and on the basis of meeting the requirement of complete degassing.

[0057] In order to illustrate the design method of a heat-melt plug hole structure for an aircraft wheel with an anti-fatigue design provided by the present invention, a specific embodiment is described.

[0058] A method for designing a hot-melt plug hole for an aircraft wheel with an anti-fatigue design comprises the following steps:

[0059] Step 1: Use finite element method to calculate the low stress area of ​​the wheel hub wall under the design load Q when no hole is drilled. The area where the MISES stress is lower than 60% of the yield strength under the design load is used as the initial layout position S1 of the hot melt plug. The position tolerance is 5% to the left and right of the axial extension. Calculate the stress in the low stress area:

[0060] σ 低 =σ 屈服 ×60%

[0061] The hub material in this embodiment is 2014 aluminum alloy, its design load Q is 464kN, and its yield strength σ 屈服 is 350MPa, and the stress σ in the low stress area 低 Should meet ≤210MPa, see Figure 3 The finite element calculation results shown in the figure determine the initial layout position of the hot melt plug S1±5%, the corresponding stress is 185MPa, and it satisfies ≤σ 低 The requirement is S1=105mm.

[0062] It should be noted that the hot melt plug preliminary arrangement position S1 is a low stress area calculated by finite element, which indicates the distance of the low stress area position relative to the fixed flange, that is, the fixed flange is selected as the reference point to position the low stress area. See Figure 4 shown. Specifically, see Figure 8 shown, Figure 8 The black line along the circumferential direction of the machine wheel is the determined hot melt plug preliminary arrangement position, that is, the S1 region.

[0063] Step 2, the main function of the hot melt plug is to sensitively respond to the temperature change of the machine wheel, and to melt the low melting alloy inside it to safely release gas when the machine wheel is overheated, so according to the installation position of the brake disc in the machine wheel, the high temperature area of the brake disc during braking is determined, according to the design experience of HB / Z 126, the high temperature area is determined as the middle of the axial direction of the brake disc, and the position tolerance is extended by 10% to the left and right of the axial direction, see Figure 4 shown, wherein S1 is the hot melt plug preliminary arrangement position, S2 is the position of the high temperature area relative to the hub, b is the distance from the outer end of the brake disc to the hub opening, and c is the length of the brake disc; wherein the position of the high temperature area relative to the hub is determined as:

[0064] S2=c / 2+b

[0065] In this embodiment, c is the length of the brake disc, c = 148 mm; b is the distance from the outer end of the brake disc to the hub opening, b = 24 mm, and S2 is calculated as 98 mm.

[0066] It should be noted that the position S2 of the high temperature area relative to the hub refers to the identified high temperature area of the brake disc, which indicates the distance of the high temperature area position of the brake disc relative to the fixed flange, that is, the fixed flange is selected as the reference point to position the high temperature area of the brake disc, see Figure 4 shown.

[0067] Step 3, according to the hot melt plug preliminary arrangement position S1 determined in step 1, combined with the high temperature area position S2 of the brake disc determined in step 2, the specific installation position of the hot melt plug is further determined, that is, the overlapping region of step 1 and step 2, denoted as S, calculated as:

[0068] S=(S1+S2) / 2

[0069] In this embodiment, S1 = 105 mm; S2 = 98 mm; and S is calculated as 101.5 mm.

[0070] Step 4, arrange the hot melt plug along the circumferential direction according to the overlapping position S determined in step 3, and the number of hot melt plugs initially set by the present application is 5, according to the hole size d and the stress concentration coefficient K tIn a plate with a limited width, the larger the hole diameter d is, the greater the stress concentration factor K is. t The stress on the hub wall increases significantly, so hot melt plug holes with a diameter of (6-10) mm are evenly arranged along the circumference of the hub wall in the overlap area S. Finite element simulation analysis is used to determine the minimum stress on the hub wall for each specification. If the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength, the design requirements are met. Otherwise, the number of hot melt plugs arranged axially is reduced by 2 at a time, and the minimum stress on the hub wall of the hot melt plug holes with a diameter of (6-10) mm are calculated until the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength. To this end, this step is to ensure a low stress concentration factor, thereby obtaining the number n and diameter of the holes on the hub wall at the overlap position S.

[0071] In this embodiment, three hot melt plug hole structures are evenly distributed along the circumference of the wheel hub. The cross-section is funnel-shaped, with a straight cylindrical portion having a diameter of 8 mm and a height of 11 mm.

[0072] Step 5. After completing step 4, determine the number of holes to be 3 and the hole diameter to be 8mm. Use finite element method to evaluate whether the wheel hub meets the life requirements under this hole condition. The stress at the hole should not exceed 1.1 times the fatigue limit of the wheel hub material. For the fatigue life diagram of the hole, see Figure 5 As shown, the assessment meets the life requirement (2000 take-offs and landings). To this end, this step is verified by using finite element life analysis to determine the number of openings, the diameter of the openings, and the location of the openings.

[0073] Step 6: The hot melt plug is a wheel safety protection device and must be completely deflated within 1 minute under extreme high temperature conditions. The deflation speed is affected by the diameter d and height h of the low-melting alloy. The height h of the low-melting alloy is affected by the wheel hub and is set to h = 6. The deflation time is calculated by introducing the number n of hot melt plugs. The calculation formula is:

[0074] p=ncp0e -Kt

[0075] Where, C d is a constant, taken as 0.8; P0 is the initial absolute pressure, P0 = 16 bar; n is the number of thermal plugs, n = 3; γ is 1.4, R = 287 J / (kg·K); T = 300 K; t is the time, t = 60 s; pressure is released to atmospheric pressure p = 1 bar; V is the gas volume, V = 1.6 m 3 d is the diameter of the low-melting alloy; c is the empirical coefficient. In this embodiment, the low-melting alloy diameter d is determined to be 5.5 mm.

[0076] The present invention finally determines the number of hot melt plug holes to be 3 through the above design. The 3 hot melt plug holes are distributed 120 degrees along the circumference of the hub. The cross-sectional view along the centerline position is consistent for the 3 hot melt plug holes. Figure 9 As shown, the distribution of the three hot melt plug holes can be seen through the forward view (a) and the reverse view (b).

[0077] The hot melt plug hole structure proposed in the present invention is evenly distributed three times along the circumference of the aircraft wheel hub. Its cross-section is funnel-shaped, with a straight cylindrical part with a diameter of 8 mm and a height of 11 mm. The funnel head is wide, which facilitates the disassembly and assembly of the hot melt plug and improves its structural maintainability.

[0078] See also Figure 6 As shown, the present invention proposes a heat-melt plug hole structure for aircraft wheels with an anti-fatigue design, wherein the fixed wheel rim 4, the movable wheel rim 5, and the heat-melt plug 6; Figure 7 FIG. 2 shows the matching diagram of the hot melt plug hole and the hot melt plug proposed by the present invention.

[0079] The present invention provides a theoretical verification method for a heat-melt plugging hole for an aircraft wheel with an anti-fatigue design, comprising:

[0080] Obtain the load generated by aircraft wheels under inflation pressure;

[0081] Based on the load generated by the inflation pressure, the tensile stress under the inflation load and the tensile stress under the simultaneous action of the lateral load and inflation load on a single aircraft wheel are obtained;

[0082] Obtain stress amplitude and average stress based on the tensile stress under inflation load and the tensile stress under the simultaneous action of lateral load and inflation load on a single aircraft wheel;

[0083] Obtain the number of fatigue cycles based on stress amplitude and mean stress;

[0084] The number of fatigue cycles is used to determine whether the hot melt plug hole structure design meets the service life requirements.

[0085] The number of fatigue cycles is obtained according to the following steps:

[0086] Obtain the equivalent stress amplitude based on the stress amplitude and the average stress;

[0087] Obtain the number of fatigue cycles based on the equivalent stress amplitude.

[0088] Specifically, judging whether the hot melt plug hole structure design meets the service life requirement according to the number of fatigue cycles includes: if the number of fatigue cycles is greater than the service life requirement, then the hot melt plug hole structure design meets the service life requirement.

[0089] In order to explain the theoretical checking method of the hot melt plug hole of the anti-fatigue design aircraft wheel, the specific examples are explained.

[0090] The present application determines the hot melt plug hole size according to the above steps, and proposes a theoretical checking method of the hot melt plug hole of the anti-fatigue design aircraft wheel, comprising the following steps:

[0091] Step 7, calculate the load generated under the inflation pressure:

[0092] P D =πP0[(R-r) 2 -R gd 2 ]

[0093] Wherein, P0 is the tire inflation pressure; R is the nominal radius of the tire; r is the tire section height R gd is the tire joint radius.

[0094] In this embodiment, P0=1.6MPa, R=420mm, r=209.5mm, R gd =105.25mm, P D =166.961kN.

[0095] Step 8, calculate the tensile stress under the inflation load:

[0096]

[0097] In the formula, h is the thickness of the hub cylinder wall at the hot melt plug hole; d is the diameter of the hot melt plug hole; a is the distance between the fixed rim and the movable rim; K t is the stress concentration coefficient.

[0098] In this embodiment, h=11mm, d=8mm, a=190mm, K t =1.5, S1=123MPa.

[0099] Step 9, calculate the tensile stress under the action of single aircraft wheel lateral load and inflation load:

[0100]

[0101] In the formula, h is the thickness of the hub cylinder wall at the hot melt plug hole; d is the diameter of the hot melt plug hole; a is the distance between the fixed rim and the movable rim; K t is the stress concentration coefficient; F C is the single aircraft wheel lateral design load; P d is the load generated by the inflation pressure.

[0102] In this embodiment, h=11mm, d=8mm, a=190mm, Kt =1.5,F c =151kN, P d =166.961kN, S2=234.36MPa.

[0103] Step 10: Calculate the stress amplitude S a1 :

[0104] S a1 =(S2-S1) / 2

[0105] In this embodiment, S1 = 123 MPa, S2 = 234.36 MPa, S a1 =55.65MPa

[0106] Step 11: Calculate the mean stress Sm:

[0107] S m =(S2+S1) / 2

[0108] In this embodiment, S1 = 123 MPa, S2 = 234.36 MPa, S m =178.7MPa

[0109] Step 12: Calculate the equivalent stress amplitude Sa:

[0110] S a =S a1 ×σ b / (σ b -S m )

[0111] In this embodiment, S a1 =55.65MPa, S m =178.7MPa,σb=460MPa,

[0112] S a =91MPa.

[0113] Step 13: Calculate the number of fatigue cycles N:

[0114] S a =1.5×σ b ×(2N) -0.087

[0115] In this embodiment, σb=460MPa, S a =91MPa, N=6475957656.

[0116] Where S a1 is the stress amplitude; S m is the mean stress; S a is the equivalent stress amplitude; σ bis the tensile strength of the hub material; N is the number of fatigue cycles. If the number of fatigue cycles is greater than the service life requirement (2000 starts and stops), the hot melt plugging structure design meets the service life requirement.

[0117] The present invention provides a fatigue-resistant hot-melt plugging structure for aircraft wheels designed using the above method.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for designing a heat-melt plug hole structure for an aircraft wheel with an anti-fatigue design, characterized in that: include: Obtain the low stress area of ​​the hub wall in the wheel assembly under design load when no hole is opened; According to the high temperature area of ​​the brake disc during braking, the position of the high temperature area relative to the wheel hub is obtained; Obtain the overlap area based on the low stress area and the high temperature area relative to the hub; Multiple heat-insulating plugs of different specifications are evenly arranged along the circumference of the hub wall in the overlapping area. Through simulation analysis, the minimum stress of the hub wall for each specification is determined, and the number, diameter, and location of the openings on the hub wall are obtained. Based on the number and diameter of the holes on the wheel hub wall, finite element analysis is used to evaluate whether the wheel hub meets the life requirements when the holes are opened. The final number of openings, the diameter of the openings, and the locations of the openings are determined based on the number of thermal plugs that meet the life requirements.

2. The method for designing a heat-melt plug hole structure for an aircraft wheel with fatigue resistance according to claim 1, characterized in that: The low stress area is an area where the MISES stress is lower than 60% of the yield strength under the design load and serves as a preliminary placement position for the thermal plug, wherein the position tolerance is 5% to the left and right of the axial extension.

3. The method for designing a heat-melt plug hole structure for an aircraft wheel with fatigue resistance according to claim 1, characterized in that: The overlap area is the arithmetic average of the positions of the low stress area and the high temperature area relative to the position of the hub.

4. The method for designing a heat-melt plug hole structure for an aircraft wheel with fatigue resistance according to claim 1, characterized in that: In the overlapping area, hot melt plug holes with a diameter of 6 to 10 mm are evenly arranged along the circumference of the hub wall. Finite element simulation analysis is used to determine the minimum stress of the hub wall for each specification. If the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength, the design requirements are met; otherwise, the number of axially arranged hot melt plugs is reduced in sequence, by 2 at a time according to the gradient, and the minimum stress of the hub wall with hot melt plug holes with a diameter of 6 to 10 mm evenly arranged in the axial direction of the hub wall is calculated respectively until the minimum MISES stress under the design load of the hub wall area is lower than 30% of the yield strength.

5. The method for designing a heat-melt plug hole structure for an aircraft wheel with fatigue resistance according to claim 1, characterized in that: Meeting the life requirements means that the stress at the opening should not exceed 1.1 times the fatigue limit of the hub material.

6. The method for designing a heat-melt plug hole structure for an aircraft wheel with fatigue resistance according to claim 1, characterized in that: The method further includes determining the low-melting alloy diameter of the thermal plug based on the final number and diameter of the openings, as well as the positions of the openings, and on the basis of meeting the requirement of complete degassing.

7. A theoretical verification method for hot-melt plugging holes for aircraft wheels designed by the method according to any one of claims 1 to 6, characterized in that: include: Obtain the load generated by aircraft wheels under inflation pressure; Based on the load generated by the inflation pressure, the tensile stress under the inflation load and the tensile stress under the simultaneous action of the lateral load and inflation load on a single aircraft wheel are obtained; Obtain stress amplitude and average stress based on the tensile stress under inflation load and the tensile stress under the simultaneous action of lateral load and inflation load on a single aircraft wheel; Obtain the number of fatigue cycles based on stress amplitude and mean stress; The number of fatigue cycles is used to determine whether the hot melt plug hole structure design meets the service life requirements.

8. The theoretical verification method for heat-melt plugging holes for aircraft wheels with fatigue resistance design according to claim 7 is characterized in that: The number of fatigue cycles is obtained according to the following steps: Obtain the equivalent stress amplitude based on the stress amplitude and the average stress; Obtain the number of fatigue cycles based on the equivalent stress amplitude.

9. The theoretical verification method for heat-melt plugging holes for aircraft wheels with fatigue resistance design according to claim 7, characterized in that: Judging whether the hot melt plug hole structure design meets the service life requirement according to the number of fatigue cycles, including: if the number of fatigue cycles is greater than the service life requirement, then the hot melt plug hole structure design meets the service life requirement.

10. A fatigue-resistant hot-melt plugging structure for aircraft wheels designed by the method according to any one of claims 1 to 6.

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