A modeling method for tire geometry model in wheel static calculation

Abstract

The application discloses a modeling method for a tire geometric model in aircraft wheel static force calculation. The method uses a rim profile to determine the size of a tire foot, uses tire specifications to determine a tire side and a tire crown profile, determines a tire inner profile according to the tire crown and the tire side profile, and finally divides the tire model into a tire crown, a tire side, a tire foot and a steel wire area to complete establishment of the tire model. The application simplifies the tire structure into a whole by ignoring the specific material distribution of the tire, forms a tire modeling method according to the tire profile characteristics and the basic material distribution characteristics, divides the tire into a tire crown, a tire side, a tire foot and a steel wire area, and thus forms a method for establishing a tire geometric model for aircraft wheel static force calculation in the case of lacking a tire material distribution map. The application has the characteristics of simplicity and convenience, and greatly reduces the risk of aircraft wheel design.

Description

Technical Field

[0001] This invention relates to the field of aircraft wheel design technology, specifically a modeling method for tire geometry in static calculations of aircraft wheels. Background Technology

[0002] In the domestic and international aircraft wheel industry, the finite element method is widely used to analyze wheel stress. During the analysis, ground loads are transmitted to the wheels through the tires; therefore, how the ground loads are applied to the wheels has a crucial impact on the wheel stress analysis results.

[0003] Currently, both domestic and international tire geometric models require the use of tire material distribution maps. Ma Lianxiang's paper "Establishment and Analysis of Aircraft Tire Model Based on Rebar Elements" in the Journal of Qingdao University of Science and Technology (Natural Science Edition, 2015, 36(03):318-321) and Li Shuai's 2018 master's thesis "Finite Element Simulation Study on Landing Impact Response Characteristics of Aircraft Tires" both rely on tire material distribution for tire geometric modeling. This method is used for bias-ply tires, but radial tires are now more commonly used in the aviation industry, and the method proposed in the papers is no longer applicable to modeling current tires. Radial tires and bias-ply tires have significant differences in material distribution and structure. In the cords, nylon cords and steel cords have significant material differences, and the different cord crossing patterns lead to substantial differences in the sidewall stiffness and modulus of radial and bias-ply tires. Furthermore, due to commercial competition and confidentiality reasons, aircraft tire manufacturers do not publicly disclose current tire models, making it difficult to legally obtain tire models. This causes difficulties for aircraft wheel manufacturers in conducting wheel stress analysis, significantly increasing the risk of design failure. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, such as difficulty in obtaining necessary modeling parameters and complexity of the modeling process, this invention proposes a modeling method for tire geometry in static calculation of machinery wheels.

[0005] The tire model produced by this invention first uses the rim profile drawing to determine the tire foot size, then uses the tire specifications to determine the tire sidewall and crown outline, then determines the tire inner outline based on the crown and sidewall outline, and finally divides the tire model into sections to determine the crown, sidewall, foot, and steel wire area, thus completing the tire model creation.

[0006] The specific process of this invention is as follows:

[0007] Step 1: Determine the model structure of the tire foot area:

[0008] The tire foot position is determined based on the rim profile drawing.

[0009] The fetal foot area includes the sides of the fetal foot and the transition rounded corners. Specifically:

[0010] Ⅰ. Draw a line parallel to the side of the rim, which is the outer edge of the tire foot. The outer edge of the tire foot is parallel to the line of symmetry of the tire cross-section.

[0011] The distance L between the outer edge of the tire foot and the line of symmetry of the tire cross section is L = (D / 2) - a; where D is the tire width and a is the width of the tire foot, a = 10~30mm.

[0012] Ⅱ. Make the transition fillet r between the side of the tire foot and the 5° line of the rim.

[0013] The radius r of the transition fillet is equal to the radius R of the rim engagement radius fillet.

[0014] Ⅲ. Draw a line parallel to the outer edge of the tire foot, which is the inner edge of the tire foot. The inner edge of the tire foot is also parallel to the line of symmetry of the tire cross-section.

[0015] The distance between the inner side of the tire foot and the symmetry line of the tire cross section is K = L - (20~30) mm.

[0016] IV. Shift the top transition fillet of the rim profile towards the center line of the rim to obtain the top transition fillet of the tire; the shift distance is the width 'a' of the tire foot. After the shift, connect the lower end of the top transition fillet of the tire with the outer edge of the tire foot to obtain the structure of the tire foot part, thus completing the determination of the tire foot part structure.

[0017] Step 2, determine the tire's outer contour structure:

[0018] The tire's outer profile is determined based on its specifications. The specific process is as follows:

[0019] Ⅰ. Using the wheel axle centerline as a reference, draw a line parallel to the wheel axle centerline to obtain the radial outer boundary line of the tire;

[0020] The distance H between the radial outer boundary line of the tire and the center line of the wheel axle is 500mm.

[0021] II. Using the symmetry line of the tire cross section as a reference, draw a line parallel to the symmetry line of the tire cross section to obtain the axial outer boundary line of the tire;

[0022] The distance J between the outer axial boundary line of the tire and the symmetry line of the tire cross section is half the width of the tire.

[0023] Ⅲ. Create the outer contour of the tire. The outer contour of the tire is arc-shaped, and the outer contour of the tire is simultaneously tangent to the tire top transition fillet, radial outer boundary line, and axial outer boundary line.

[0024] Step 3; Determine the inner profile of the tire:

[0025] I. Translate the outer contour of the tire towards the center of the tire to obtain the main arc of the inner contour of the tire.

[0026] The upper endpoint of the main arc of the inner contour of the tire intersects the symmetry line of the tire's cross-section, and the lower endpoint is flush with the lower end of the outer contour of the tire. The distance G of movement is 30mm.

[0027] II. Construct the inner contour of the tire. Starting from the lower end of the main arc of the inner contour, draw a tangent line towards the center of the tire, ensuring that the endpoint of this tangent line intersects the inner edge of the tire bead. This tangent line is the tire bead tangent line of the inner contour. The interconnected main arc of the inner contour and the tire bead tangent line together constitute 1 / 4 of the tire's inner contour.

[0028] Step 4, divide the tire cross-section:

[0029] The tire cross section is divided to obtain the tire crown, tire sidewall, and tire foot.

[0030] When dividing the tire crown, a line segment is drawn from the center of the tire to the outer diameter of the tire. This line segment is the tire crown dividing line, and the angle α between the tire crown dividing line and the tire cross-sectional symmetry line is 40°. The area between the tire cross-sectional symmetry line and the tire crown dividing line is the tire crown.

[0031] When dividing the tire sidewall, a line segment is drawn from the center of the tire to the outer diameter of the tire. This line segment is the tire sidewall dividing line, and the angle β between the tire sidewall dividing line and the tire crown dividing line is 50°. The area between the tire sidewall dividing line and the tire crown dividing line is the tire sidewall.

[0032] After separating the tread and sidewall, the remaining area is the foot.

[0033] Step 5, determine the tire base wires:

[0034] Determine the center of the wire. When determining the center of the wire, it must be located within the tire bead area.

[0035] The distance F between the center of the steel wire and the inner side of the tire foot is 22.5 mm, and the distance T between the steel wire and the 5° line is 13 mm.

[0036] The diameter d of the steel wire is 10 mm.

[0037] Through the above steps, a geometric model of a 1000×350R508 tire for static wheel calculation is obtained.

[0038] This invention ignores the specific material distribution of the tire, simplifies the tire structure into a whole, and forms a tire modeling method based on the tire contour features and basic material distribution characteristics. The tire is divided into four major material distribution areas: the tire crown, the tire sidewall, the tire bead, and the steel wire. This forms a method for establishing a tire geometric model for wheel static calculation in the absence of a tire material distribution map.

[0039] Compared with the prior art, the advantages of this invention are:

[0040] This invention proposes a tire geometry modeling method for static calculation of machinery wheels, which has the following advantages:

[0041] 1. The tire modeling method proposed in this invention does not require a tire material distribution map; it only requires inputting a rim profile and tire model. The rim profile and tire model are obtained in the early design phase from relevant standards, enabling aircraft wheel manufacturers to establish tire models and perform stress analysis during the initial design stage. This invention simplifies the tire structure into a single unit and divides the tire into four major material distribution areas—the tread, sidewall, bead, and steel wire—based on the tire's basic material distribution characteristics. This provides a method for establishing a simplified tire geometric model for static analysis of aircraft wheels, even in the absence of a tire material distribution map.

[0042] 2. The tire modeling method proposed in this invention provides a legal, simple, and quick way to obtain tire models. Existing tire modeling methods require establishing the geometry of the tire crown, shoulder, steel wires, and cords based on the tire's material distribution, and then embedding the steel wires and cord layers into the rubber mass to create the tire model. However, nylon cords and steel cords have significant material differences and different cord crossing patterns, leading to substantial differences in sidewall stiffness and modulus between radial and bias-ply tires. The tire modeling method proposed in this invention eliminates the need for material distribution diagrams and nylon / steel cord structures. Instead, it uses a comprehensive tire structure with reinforced materials to replace the complex modeling of cord layers. Aircraft wheel manufacturers only need to focus on the overall stress and load characteristics of the tire. Therefore, aircraft wheel manufacturers can use the tire modeling method proposed in this invention to conduct aircraft wheel design work, significantly reducing the risk of design failure.

[0043] 3. The tire modeling method proposed in this invention avoids commercial competition and keeps secrets. The tire model can be completed simply by following the manufacturing steps based on the rim profile and tire model. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the wheel rim profile;

[0045] Figure 2 This is a diagram of the fetal feet;

[0046] Figure 3 This is a schematic diagram of the outer outline;

[0047] Figure 4 It is 1 / 2 of the tire cross-section profile;

[0048] Figure 5 This is a diagram showing the tire zone configuration;

[0049] Figure 6 This is a schematic diagram of the steel wire;

[0050] Figure 7 This is a flowchart of the present invention.

[0051] In the diagram: 1. Rim profile; 2. Tire cross-sectional symmetry line; 3. Axle centerline; 4. Outer edge of tire foot; 5. Transition fillet; 6. Inner edge of tire foot; 7. Outer tire contour; 8. Inner tire contour; 9. Crown area; 10. Sidewall area; 11. Foot area; 12. Steel wire area; 13. Radial outer boundary line; 14. Axial outer boundary line; 15. Main arc line of tire inner contour; 16. Foot tangent; 17. Crown dividing line; 18. Transition fillet at the top of rim profile; 19. Transition fillet at the top of tire. Detailed Implementation

[0052] This embodiment takes a 1000×350R508 tire of a certain aircraft as an example to establish a method for establishing a tire geometric model in the static calculation of the wheel. The obtained tire geometric model is a 1 / 4 model.

[0053] The specific process of this embodiment is as follows:

[0054] Step 1: Determine the model structure of the tire foot area:

[0055] The tire foot location is determined based on the rim profile drawing. This rim profile drawing is obtained according to GB-T9746-2013.

[0056] The fetal foot area includes the sides of the fetal foot and the transition rounded corners. The specific process is as follows:

[0057] Ⅰ. Draw a line parallel to the side of the wheel rim; this line is the outer edge 4 of the tire foot. The outer edge 4 of the tire foot is parallel to the tire cross-sectional symmetry line 2, and the distance between the outer edge 4 and the tire cross-sectional symmetry line 2 is L = (D / 2) - a; where D is the tire width, and a is the width of the tire foot, a = 10~30mm. In this example, L = 155mm.

[0058] Ⅱ. Create a transition fillet r between the tire foot side 4 and the rim 5° line. The radius of this transition fillet is equal to the radius of the rim engagement diameter fillet R. The radius of the rim engagement diameter fillet R is obtained from the rim profile drawing according to GB-T9746-2013.

[0059] III. Draw a line parallel to the outer edge 4 of the tire foot, which is the inner edge 6 of the tire foot. The inner edge 6 of the tire foot is also parallel to the tire cross-sectional symmetry line 2, and the distance between the inner edge 6 and the tire cross-sectional symmetry line 2 is K = L - (20~30) mm. In this example, K = 110 mm.

[0060] IV. The top transition fillet 18 of the rim profile is translated towards the center line of the rim to obtain the top transition fillet 19 of the tire; the translation distance is the width a of the tire foot. After translation, the lower end of the top transition fillet 19 of the tire is connected to the outer side 4 of the tire foot to obtain the structure of the tire foot part, thus completing the determination of the structure of the tire foot part.

[0061] Step 2, determine the tire's outer contour structure:

[0062] The tire's outer profile is determined based on its specifications. The specific process is as follows:

[0063] Ⅰ. Using the wheel axle centerline 3 as a reference, draw a line parallel to the wheel axle centerline 3 to obtain the radial outer boundary line 13 of the tire; the distance H between the radial outer boundary line 13 of the tire and the wheel axle centerline 3 is 500mm.

[0064] II. Using the tire cross-section symmetry line 2 as a reference, draw a line parallel to the tire cross-section symmetry line to obtain the axial outer boundary line 14 of the tire; the distance J between the axial outer boundary line 14 of the tire and the tire cross-section symmetry line 2 is half the tire width, and in this example J = 175 mm.

[0065] Ⅲ. Make the outer contour of the tire 7. The outer contour of the tire is arc-shaped, and the outer contour of the tire is simultaneously tangent to the tire top transition fillet 19, the radial outer boundary line 13 and the axial outer boundary line 14.

[0066] Step 3; Determine the inner profile of the tire:

[0067] I. The outer contour 7 of the tire is translated towards the center of the tire to obtain the main arc line 15 of the inner contour of the tire. The upper end of the main arc line of the inner contour of the tire intersects the symmetry line of the tire cross section, and the lower end is flush with the lower end of the outer contour 7 of the tire. The distance G of the translation is 30mm.

[0068] II. Construct the inner contour 8 of the tire. Starting from the lower end of the main arc line 15 of the inner contour of the tire, draw a tangent line towards the center of the tire, and make the end point of the tangent line intersect the inner side edge 6 of the tire foot. This tangent line is the tire foot tangent line 16 of the inner contour of the tire. The interconnected main arc line 15 and tire foot tangent line 16 together form 1 / 4 of the inner contour 8 of the tire.

[0069] Step 4, divide the tire cross-section:

[0070] The tire cross section is divided to obtain the tire crown 9, tire sidewall 10 and tire foot 11.

[0071] When dividing the tire crown, a line segment is drawn from the center of the tire to the outer diameter of the tire. This line segment is the tire crown dividing line 17, and the angle α between the tire crown dividing line and the tire cross-sectional symmetry line 2 is 40°. The area between the tire cross-sectional symmetry line 2 and the tire crown dividing line 17 is the tire crown.

[0072] When dividing the tire sidewall, a line segment is drawn from the center of the tire to the outer diameter of the tire. This line segment is the tire sidewall dividing line 18, and the angle β between the tire sidewall dividing line and the tire crown dividing line 17 is 50°. The area between the tire sidewall dividing line 18 and the tire crown dividing line 17 is the tire sidewall.

[0073] After separating the tummy crown and sidewall, the remaining area is the tummy foot 11.

[0074] Step 5, determine the tire base wires:

[0075] Determine the center of the wire. When determining the center of the wire, the center of the wire is located within the tire foot 11 area, and the distance F between the center of the wire and the inner edge of the tire foot is 22.5 mm, and the distance T from the 5° line is 13 mm.

[0076] The diameter d of the steel wire is 10 mm.

[0077] Through the above steps, a geometric model of a 1000×350R508 tire for static wheel calculation is obtained.

Claims

1. A modeling method for tire geometry in static calculation of machinery wheels, characterized in that, The specific process is as follows: Step 1: Determine the model structure of the tire foot area: The tire foot position is determined based on the rim profile drawing; The foot portion includes the side of the foot and the transition rounded corner; The specific process is as follows: Ⅰ Draw a parallel line to the side of the rim, which is the outer edge of the tire foot (4); the outer edge of the tire foot is parallel to the line of symmetry of the tire cross section (2); II. Create a fillet radius r between the tire foot side and the 5° line of the rim; Ⅲ Draw a line parallel to the outer edge of the tire foot, which is the inner edge of the tire foot (6); the inner edge of the tire foot is also parallel to the line of symmetry of the tire cross section; IV. The top transition fillet (18) of the rim profile is translated to one side of the center line of the rim to obtain the top transition fillet (19) of the tire; the translation distance is the width a of the tire foot; after translation, the lower end of the top transition fillet of the tire is connected to the outer side (4) of the tire foot to obtain the structure of the tire foot part, and the determination of the structure of the tire foot part is completed. Step 2, determine the tire's outer contour structure: The outer profile of the tire is determined according to its specifications; the specific process is as follows: Ⅰ Using the wheel axle centerline (3) as a reference, draw a line parallel to the wheel axle centerline to obtain the radial outer boundary line (13) of the tire; II. Using the tire cross-sectional symmetry line (2) as a reference, draw a line parallel to the tire cross-sectional symmetry line to obtain the axial outer boundary line (14) of the tire. Ⅲ Make the outer contour of the tire (7); the outer contour of the tire is arc-shaped, and the outer contour of the tire is simultaneously tangent to the top transition fillet (19), the radial outer boundary line and the axial outer boundary line of the tire; Step 3; Determine the inner profile of the tire: Ⅰ. Translate the outer contour of the tire (7) toward the center of the tire to obtain the main arc line (15) of the inner contour of the tire; II. Make the inner contour of the tire (8); take the lower end of the main arc of the inner contour of the tire as the starting point, draw a tangent line towards the center of the tire, and make the end point of the tangent line intersect with the inner side of the tire foot (6). The tangent line is the tire foot tangent line (16) of the inner contour of the tire; the main arc of the inner contour of the tire (15) and the tire foot tangent line together form 1 / 4 of the inner contour of the tire. Step 4, divide the tire cross-section: The tire cross section is divided to obtain the tire crown (9), tire sidewall (10) and tire foot (11); When dividing the tire crown, starting from the center of the tire, draw a line segment towards the outer diameter of the tire. This line segment is the tire crown dividing line (17), and the angle α between the tire crown dividing line and the tire cross-sectional symmetry line (2) is 40°. The area between the tire's cross-sectional symmetry line and the tire crown dividing line is the tire crown. When dividing the tire sidewall, a line segment is drawn from the center of the tire to the outer diameter of the tire. This line segment is the tire sidewall dividing line (18), and the angle β between the tire sidewall dividing line and the tire crown dividing line is 50°. The area between the tire sidewall dividing line and the tire crown dividing line is the tire sidewall. After dividing the tummy crown and sidewall, the remaining area is the tummy foot (11); Step 5, determine the tire base wires: Determine the center of the steel wire; in determining the center of the steel wire, the center of the steel wire is located within the tire foot area; the diameter d of the steel wire is 10 mm; This completes the modeling of the tire geometry in the static calculation of the wheel.

2. The modeling method for tire geometry in the static calculation of machinery wheels as described in claim 1, characterized in that, The distance L between the outer edge of the tire foot and the symmetry line (2) of the tire cross section is (D / 2)-a; where D is the tire width and a is the width of the tire foot, a = 10~30mm.

3. The modeling method for tire geometry in the static calculation of machinery wheels as described in claim 1, characterized in that, The radius r of the transition fillet is equal to the radius R of the rim engagement radius fillet.

4. The modeling method for tire geometry in the static calculation of wheel as described in claim 1, characterized in that, The distance between the inner side of the tire foot and the symmetry line (2) of the tire cross section is K = L - (20~30) mm.

5. The modeling method for tire geometry in the static calculation of wheels as described in claim 1, characterized in that, The distance H between the radial outer boundary line (13) of the tire and the center line (3) of the wheel axle is 500mm.

6. The modeling method for tire geometry in the static calculation of wheel as described in claim 1, characterized in that, The distance J between the axial outer boundary line (14) of the tire and the symmetry line of the tire cross section is half the width of the tire.

7. The modeling method for tire geometry in the static calculation of wheel as described in claim 1, characterized in that, The upper end of the main arc of the inner contour of the tire intersects the symmetry line of the tire cross section, and the lower end is flush with the lower end of the outer contour (7) of the tire; the moving distance G is 30mm.

8. The modeling method for tire geometry in the static calculation of a wheel as described in claim 1, characterized in that, The distance F between the center of the steel wire and the inner side of the tire foot is 22.5 mm, and the distance T between the steel wire and the 5° line is 13 mm.

Images