A tire tread pattern modeling and finite element mesh generation method based on ABAQUS
By simplifying the 3D modeling process of tire tread patterns and using ABAQUS software to generate high-quality finite element meshes, the problem of mesh generation difficulties in tire performance simulation analysis in existing technologies has been solved, thereby improving the efficiency and accuracy of tire performance simulation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2022-09-23
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies struggle to generate high-quality finite element meshes for tire tread patterns, leading to large errors in tire performance simulation analysis results, especially in the numerical simulation of passenger car tire mechanical performance, where there is a lack of accurate modeling.
By simplifying the 3D modeling process of tire tread patterns, using the DXF file of the early 2D design of the pattern, and combining it with ABAQUS software, a high-quality finite element mesh is generated, including steps such as cleaning up the drawings, extracting the contour curves, unfolding the contour, transforming control points, building a solid model, and mesh transformation.
It enables the rapid creation of 3D models of complex patterns and the generation of high-quality finite element meshes, improving the efficiency and accuracy of tire performance numerical simulation and laying the foundation for tire performance simulation.
Smart Images
Figure CN115510557B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a technology for creating a three-dimensional model of tire tread patterns and generating high-quality finite element meshes based on two-dimensional CAD design drawings of tire tread patterns using the finite element simulation software ABAQUS. Background Technology
[0002] Tires are the only point of contact between a vehicle and the road. As a crucial component of tires, the tread pattern significantly impacts various performance characteristics, including noise, traction, snow performance, steering, and braking. With the development of computer technology, numerical simulation has become a primary method in the tire industry for predicting and evaluating tire performance. However, current performance simulation analyses mainly focus on smooth tires and tires with longitudinal grooves. While simplified tread pattern models improve modeling efficiency to some extent, the lack of precise tread pattern modeling inevitably introduces errors into the analysis results. This is especially true for numerical simulations of passenger car tire mechanical properties, where accurate tread pattern modeling is essential.
[0003] In the design and analysis of tire tread patterns, the first step is to establish the two-dimensional geometric structure of the pattern, and then perform three-dimensional modeling based on this. The process of creating a three-dimensional model involves complex surface manipulations, which places high demands on engineering designers. Finally, the three-dimensional model needs to be converted into a finite element mesh for computation. Due to the complexity of the tire tread pattern structure, general-purpose finite element software often struggles to generate high-quality meshes, as mesh generation is mostly done in specialized mesh generation software, such as HyperMesh, and the process is cumbersome and complex. Therefore, simplifying the tire tread pattern modeling process and generating high-quality finite element meshes significantly improves the efficiency and accuracy of tire performance numerical simulations, and lays the foundation for designing tires with superior performance. Summary of the Invention
[0004] The purpose of this invention is to simplify the three-dimensional modeling process of tire tread patterns by using the DXF file, a two-dimensional design file from the early stage of the tread pattern, through coordinate transformation. The simplified three-dimensional tread pattern model can then be easily used to generate a high-quality finite element mesh using general finite element preprocessing software.
[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A method for tire tread pattern modeling and finite element mesh generation based on ABAQUS mainly includes the following steps: The first step is to clean up the 2D drawings of the tread pattern design. Based on the 2D AutoCAD drawings of the tread pattern design, remove unnecessary information such as defined annotation text and annotation lines, and only keep the geometric elements related to the pattern, including lines and arcs. Then, use the DXFOUT command to output the pattern drawing as a DXF file.
[0006] The second step is to extract the tread pattern outline curve. Based on the cleaned drawing from the first step, extract the tread outline curve from the drawing and output the outline curve as a separate DXF file. To facilitate subsequent processing, before outputting the DXF file, place the upper and lower outline curves on different layers, and at the same time, shift the coordinates of the upper center point of the outline to the origin CP(0, 0).
[0007] The third step is to generate contour boundary control points. Considering the axisymmetric nature of the tread pattern contour, only the right half of the contour needs to be taken. Finally, the completed contour control points can be obtained by mirroring the contour center point. First, set the number of discrete points N for the upper contour and the lower contour curve. Discretize the contour boundary according to the number of control points N, while ensuring that the upper and lower contours have the same number of control nodes N. Next, calculate the lengths of the upper and lower parts of the tire tread, denoted as topLen and bottomLen, respectively. Then, calculate the discrete distance of the contour curve based on the contour length and the number of control points N. Finally, place the control nodes of the upper contour in the topNodes array variable and the control nodes of the lower contour in the btmNodes array variable. The array variables store a three-dimensional spatial coordinate point structure containing three variables: x, y, and z.
[0008] The fourth step is to unfold the tread profile curve. The original tread pattern profile is an arc, which is not conducive to tread pattern modeling. To avoid this problem, the purpose of unfolding in this step is to unfold the arc-shaped tread profile into a straight plane. Considering the axisymmetric nature of the tread pattern profile, only the right half of the profile needs to be taken. The specific unfolding rules are as follows: First, calculate the length l of the tread profile to obtain the coordinates of the starting point of the unfolded straight line SP(0, 0) and the coordinates of the ending point EP(l, 0).
[0009] Step 5: Transformation of the upper control points of the tread profile. Following the operations in step 2, the coordinates of the center point of the tread profile are CP(0, 0). The purpose of this step is to transform the control points of the upper part of the original profile onto the straight profile of step 4. The implementation method is as follows: First, iterate through each control point in the topNodes array of step 3 to obtain the corresponding control point p(x,y). Then, calculate the curve length s from the coordinates of the profile center point to the position of point p. Thus, the coordinates of the point on the straight profile can be represented as p. ’(s, 0), and finally the calculated coordinates are stored in the array variable topTemp.
[0010] Step 6: Determine the positional relationship of the original contour. The positional relationship between the upper and lower parts of the original contour is crucial for the transformation. In this invention, the positional relationship between contours is mainly determined by control points. This step is mainly used to determine the position of the lower part of the contour relative to the upper part. The specific implementation process is as follows: First, traverse the array variable btmNodes of the lower contour control points obtained in Step 3 to obtain the coordinates p(x, y). Then, record the position index of point p in the array as i. Through the array position indices i and i+1, obtain the corresponding coordinate points p1 and p2 in topNodes. Record vectors v1 = p - p1 and v2 = p1 - p2. Finally, calculate the magnitude ds of vector v1 and the angle from vector v1 to v2. By using the length ds and angle relative to the corresponding position of the upper curve of the contour This means that the positional relationship of the control points can be uniquely determined.
[0011] Step 7: Transformation of the lower control points of the tread profile. Based on steps 5 and 6, generate the lower control points of the profile curve. The specific implementation process is as follows: First, iterate through the topTemp array calculated in step 5, subtracting 1 from the length, to obtain two adjacent points p1(x, y) and p2(x, y), and denote the vector v = p2 - p1; then rotate the vector v clockwise. Get vector v ’ Then, point p1 is aligned with vector v. ’ Move the position by a distance ds in the direction to obtain the coordinates of the lower control point of the tread profile; finally, store the new coordinates in the btmTemp array.
[0012] Step 8: Set the tread pattern pitch length. According to the tread pattern design requirements, set the pitch length pitchLen (mm).
[0013] Step 9: Create a solid model of the tread profile. After the above steps, the tread profile becomes a flat surface. Based on the pitch length pitchLen in step 8, use the solid modeling commands provided by Abaqus to complete the creation of the 3D model of the tread profile.
[0014] Step 10: Establish the tread pattern geometry model. The establishment of the tread pattern model is completed based on step 9. The tread pattern grooves can be created using the grooving command in solid modeling.
[0015] Step 11: Generate the pattern 3D mesh. With the help of Abaqus' built-in solid cutting tools and powerful mesh generation function, a high-quality 3D pattern finite element mesh can be easily created, and the node and element information can be output to the INP file.
[0016] Step 12: Set the outer diameter D (mm) of the tire tread. Based on the specific model and specifications of the tire, obtain its maximum outer diameter as D.
[0017] Step 13: Transform the tread pattern mesh laterally along the tire tread. This step mainly transforms the 3D mesh in reverse according to the tread contour curve in step 2, generating an actual tread pattern mesh with a certain curvature from the flat tread pattern mesh according to the original outer contour shape. The specific implementation process is as follows: First, traverse each cell in the mesh and extract the coordinates of each node in the cell, denoted as p(x, y, z). For ease of calculation, let z equal 0 in the cell node coordinates, so the node can be denoted as p(x, y, 0); Second, calculate the horizontal distance dx and horizontal distance dy between point p and the contour center coordinate point CP. It is easy to know that the angle between the straight line of point p along the y-axis and the flat surface is 90 degrees. At the same time, it is assumed that the coordinate distance of the node located to the right of the contour center point CP is positive, and the coordinate distance of the node located to the left of the contour center point CP is negative; Then, according to the upper curve of the original tread contour, the transformed reference node coordinates q(x, y, z) are obtained by translating according to the distance from the contour center point CP. The movement rule is as follows: if the distance is positive, start from the center point CP and move a distance dx along the right side of the contour line; otherwise, start from the center point CP and move a distance dx along the left side of the contour line. Finally, calculate the normal vector n of the upper curve of the tread contour through the reference node q, and move the coordinate q a distance dy according to the vector n. After the movement, the coordinate p of the transformed element node p is obtained. ’ The function iterates through (x', y', z) and updates the original element node coordinates. The elements with transformed node coordinates are then stored in the `elements` array variable.
[0018] Step fourteen: Transform the tread pattern grid along the longitudinal direction of the tire tread. Besides its lateral curvature, the tread pattern structure also has a certain curvature along its longitudinal direction. This step mainly achieves the transformation of the grid in the circumferential direction. First, based on the tire tread outer diameter D and the tread pitch length pitchLen, the arc angle of the tread pattern along the tire circumference can be obtained as follows: =2*pitchLen / D, the outer radius of the tire tread is R=D / 2; then iterate through the elements array in step thirteen, take out the coordinates of each node in the cell, denoted as p(x, y, z), and calculate its distance dy to the XZ coordinate plane. The radius of the arc where this point is located should be R. ’ =R-dy; then calculate the distance from this point to the radius R.’ Let dz be the horizontal distance from the highest point T(x, y, z) of the arc, and assume that it is located at the highest point T(pitchLen / 2, 0, R). ’ The distance to the right is taken as a positive value, and the distance to the left of the highest point T of the arc is taken as a negative value; the coordinates of the node after the transformation can be determined by the arc length ds that the arc vertex T moves along the arc, and ds can be calculated by the following formula.
[0019] ds= ; In the formula R ’ dz is the radius of the arc, and dz is the horizontal distance from the current node to the highest point T of the arc. `T` is the arc angle, and `pitchLen` is the pattern pitch length. Similarly, if the distance is positive, the node moves clockwise along the arc from the arc vertex `T`, and counter-clockwise along the arc if the distance is negative. The coordinates of the point after the movement are the node after the transformation, and the original node coordinates are updated.
[0020] Step 15: Create a mesh file. After the transformations in steps 13 and 14, the mesh fully meets the requirements. Create a 3D patterned mesh INP file that can be used for simulation calculations, according to the input format requirements of the ABAQUS software.
[0021] The method for tire tread pattern modeling and high-quality finite element mesh generation based on ABAQUS can be embedded into finite element simulation software through secondary development programming.
[0022] The ABAQUS-based method for tire tread pattern modeling and high-quality finite element mesh generation can be used for numerical simulation of tire mechanical properties and tire performance simulation.
[0023] This invention proposes an ABAQUS-based method for tire tread pattern modeling and high-quality finite element mesh generation. By simplifying the tread pattern modeling process and avoiding complex surface modeling operations, it can quickly establish a 3D model of complex tread patterns. The simplified 3D model can then be used to generate a high-quality finite element mesh using general-purpose finite element preprocessing software. This tread pattern modeling and mesh generation technology can significantly improve the efficiency of tread pattern modeling and the quality of the 3D finite element mesh in the numerical simulation of tire mechanical performance, laying the foundation for accurate simulation of tire performance. Furthermore, this technology can be easily embedded into existing finite element simulation software through secondary development programming. Attached Figure Description
[0024] Figure 1 This is a flowchart illustrating the implementation process of complex pattern 3D modeling and mesh generation in this invention; Figure 2 This is a schematic diagram of the tread contour control points; Figure 3 This is a schematic diagram of the tire tread profile transformation; Figure 4 This is a schematic diagram of the 3D pattern modeling process and mesh generation; Figure 5 This is a schematic diagram of a three-dimensional patterned mesh transformation. Detailed Implementation
[0025] The present invention will be further described in detail below with reference to the accompanying drawings: This embodiment is implemented under the premise of the technical solution of the present invention, and detailed implementation methods are given, but the protection scope of the present invention is not limited to the following embodiments. Example
[0026] Figure 1 This is a flowchart of the implementation of the processing method of the present invention. The following is a detailed explanation of the processing method and process of the present invention, using an example of three-dimensional modeling and finite element mesh generation of a certain tread pattern of a 225 / 60R18 car radial tire.
[0027] The first step is to clean up the 2D drawings of the tread pattern design. Based on the 2D AutoCAD drawings of the tread pattern design, remove unnecessary information such as defined annotation text and annotation lines, and only keep the geometric elements related to the pattern, including lines and arcs. Use the DXFOUT command to output the pattern drawing as a DXF file and name it pattern.dxf.
[0028] The second step is to extract the tread pattern outline curve. Based on the cleaned drawing from the first step, extract the tread outline curve from the drawing and output the outline curve as a separate DXF file. To facilitate subsequent processing, before outputting the DXF file, place the upper and lower outline curves on different layers. At the same time, shift the coordinates of the upper center point of the outline to the origin CP(0, 0). Output the tread outline as lunkuo.dxf.
[0029] The third step is to generate contour boundary control points. Considering the axisymmetric characteristics of the tread pattern contour, the right half of the contour can be taken. Finally, the completed contour control points can be obtained by mirroring the center point of the contour. First, set the number of discrete points N=100 for the upper contour and the lower contour curve. Then, calculate the lengths of the upper and lower contour lines respectively, obtaining topLen=233.62 / 2mm and bottomLen=226.37 / 2mm. The unit discrete lengths of the contour lines are 1.1681mm and 1.13185mm respectively. Finally, based on the unit discrete lengths, the coordinates of the control points in the upper contour are (0, 0), (1.35, 0.01), (2.7, 0.03), (4.05, 0.03), …, (139.17, -22.85); the coordinates of the nodes in the lower contour are (0, -7.85), (1.35, -7.83), (2.7, -7.82), (4.05, -7.8), …, (139.17, -22.85). Figure 2 As shown. Finally, place the control nodes of the upper part of the outline into the topNodes array variable, and place the control nodes of the lower part of the outline into the btmNodes array variable.
[0030] The fourth step is to unfold the tread profile curve. The original tread pattern profile is an arc, which is not conducive to tread pattern modeling. To avoid this problem, the purpose of unfolding in this step is to unfold the arc-shaped tread profile into a straight plane. The length of the tread profile line is l = 233.62 mm. Obviously, the starting coordinates of the unfolded straight line are SP(0, 0) and the ending coordinates are EP(233.62 / 2, 0).
[0031] The fifth step involves transforming the control points on the upper part of the tread profile. Following the operations in the second step, the center point coordinates of the tread profile are CP(0, 0). The purpose of this step is to transform the control points on the upper part of the original profile onto the straight profile of the fourth step. Considering that the control nodes were generated at equal intervals in the third step, the control point transformation rule in the fifth step should also be equal intervals on the straight profile line. Thus, the coordinates of the control nodes are: (0, 0), (1.1681, 0), (2.3362, 0), (3.5043, 0), (4.6724, 0), (5.8405, 0),…(116.81, 0). Finally, the calculated coordinate points are stored in the array variable topTemp.
[0032] Step 6: Determine the positional relationship of the original contour. The positional relationship between the upper and lower parts of the original contour is crucial for the transformation. In this invention, the positional relationship between contours is mainly determined by control points. This step is mainly used to determine the position of the lower part of the contour relative to the upper part. First, iterate through the array variable btmNodes of the lower contour control points obtained in Step 3 to obtain the coordinates p(0, -7.85). The current position index of p in the array is 0. By using the array position indices 0 and 1, we obtain the corresponding coordinate points p1(0, 0) and p2(1.35, 0.01) in topNodes. Let vectors v1=(0, -7.85) and v2=(-1.35, -0.01). Finally, we calculate the magnitude ds=7.85mm of vector v1 and the angle from vector v1 to v2. =89.9 degrees, through length ds and angle That is, the positional relationship between the upper and lower contour control points can be uniquely determined, such as Figure 3 As shown.
[0033] Step 7: Transformation of the lower control points of the tread profile. Based on steps 5 and 6, generate the lower control points of the profile curve. First, iterate through the topTemp array calculated in step 5, subtracting 1 from the length, to obtain two adjacent points p1(1.35, 0.01) and p2(2.7, 0.03). Let the vector v = p2 - p1 = (1.35, 0.02). Then, rotate the vector v clockwise. =89.9 degrees to obtain vector v ’ =(1.3524, -1.3401); then, according to vector v, point p1 is... ’ Move the control point ds = 7.85 mm in the direction it is in to obtain the coordinates of the lower control point of the tread profile (1.3637, -7.8400); finally, store the new coordinates in the btmTemp array.
[0034] Step 8: Set the tread pattern pitch length. According to the tread pattern design requirements, the pitch length is pitchLen = 35.8 (mm).
[0035] Step nine: Create a solid model of the tire tread profile. After the above steps, the tire tread profile becomes a flat surface, as shown below. Figure 4 As shown in (a) and (b), based on the pitch length of 35.8 mm in step eight, the 3D model of the tire tread profile was created using Abaqus' built-in solid modeling commands. The created 3D profile model is shown below. Figure 4 As shown in -(c).
[0036] Step 10: Establish the tread pattern geometry model. The tread pattern model is built upon step 9. Tread grooves are created using the grooving command in solid modeling. The completed 3D tread pattern model looks like this: Figure 4 As shown in -(d).
[0037] Step 11: Generate the 3D mesh of the pattern. Using Abaqus' built-in solid cutting tools and powerful mesh generation capabilities, a high-quality 3D pattern finite element mesh can be easily created. The resulting 3D pattern model after mesh generation looks like this: Figure 4 As shown in -(e), the node and cell information is finally output to the INP file.
[0038] Step 12: Set the outer diameter of the tire tread D (mm). Based on the tire model and specifications, its maximum outer diameter is D=727 mm. Therefore, the tire radius R=D / 2 equals 363.5 mm.
[0039] Step 13: Transform the tread pattern mesh laterally along the tire tread. This step mainly involves transforming the 3D mesh in reverse according to the tread contour curve in step 2, generating an actual tread pattern mesh with a certain curvature from the flat tread pattern mesh according to the original outer contour shape, such as... Figure 5As shown in (a). First, traverse each cell in the grid to obtain the coordinate data of that cell node. In this embodiment, the cell node coordinates are (1.32, 0, 5.21), (2.74, 0, 5.21), (2.74, 0, 6.45), (1.32, 0, 6.45), (1.32, -1.38, 5.21), (2.74, -1.38, 5.21), (2.74, -1.38, 6.45), (1.32, -1.38, 6.45), a total of 8 nodes. Next, perform coordinate transformation on each node and traverse these 8 node coordinates. For ease of calculation, set z to 0 in the cell node coordinates. Thus, the nodes can be recorded as (1.32, 0, 0), (2.74, 0, 0), (2.74, 0, 0), (1.32, 0, 0), (1.32, -1.38, 0), (2.74, -1.38,0), (2.74, -1.38, 0), (1.32, -1.38, 0); further calculations show that the horizontal distance dx and vertical distance dy of these 8 nodes from the contour center coordinate point CP(0, 0) are (1.32, 2.74, 2.74, 1.32, 1.32, 2.74, 2.74, 1.32) and (0, 0, 0, 0, 1.38, 1.38, 1.38, 1.38) respectively. Since the coordinate position of the current element is located to the right of the contour center point CP, the distances are all positive values. Then, according to the upper curve of the original tread contour, starting from the contour center point CP, move 1.32mm along the contour line to obtain the corresponding reference node coordinates on the contour line as (1.312, -0.01), calculate the normal vector of the contour line passing through the reference node (1.312, -0.01) as n = (0, -0.001), move the reference node along n by a distance dy = 0, and obtain the coordinates p of the element node after transformation. ’ (1.312, -0.01, 5.21). The same operation can be performed on the remaining nodes in this cell to obtain the transformed node coordinates. The cells with transformed node coordinates are then stored in the `elements` array variable.
[0040] Step fourteen: The tread pattern mesh is transformed along the longitudinal direction of the tread. Besides its lateral curvature, the tread pattern structure also has a certain curvature along its longitudinal direction. This step mainly achieves the transformation of the mesh in the circumferential direction, such as... Figure 5As shown in (b). First, based on the tire tread outer diameter D=727mm and the tread pitch length pitchLen=35.8mm, the arc angle of the tread pattern along the tire circumference can be obtained as β=2*pitchLen / D=5.643 degrees, and the tire tread outer radius R=D / 2=363.5mm; then, iterate through the elements array in step thirteen and extract the coordinates of the cell nodes (1.312, -0.01, 5.21), (2.62, -0.01, 5.21), (2.62, -0.01, 6.45), (1.312, -0.01, 6.45), (1.274, -1.41, 5.21), (2.41, -1.42, 5.21), (2.41, -1.42, 6.45). The distances dy from the nodes to the XZ coordinate plane are calculated as (1.274, -1.41, 6.45), respectively (0.01, 0.01, 0.01, 0.01, 1.41, 1.42, 1.42, 1.41). Given the arc radius R = 363.5 mm, the arc radius R of each point is calculated. ’ =R-dy is (363.49, 363.49, 363.49, 363.49, 362.09, 362.08, 362.08, 362.09); then, based on the coordinates of each node in the element, its distance radius R is calculated. ’ The horizontal distance dz at the highest point T of the arc is (5.21, 5.21, 6.45, 6.45, 5.21, 5.21, 5.21, 6.45, 6.45), see [reference needed]. Figure 5 As shown in (b). Based on pitchLen = 35.8 mm, =5.643 degrees and the dz value of each point. The transformed node coordinates can be determined by moving the arc vertex T of the arc where the point is located along the arc by an arc length ds. ds can be calculated by the following formula.
[0041] ds= ; The distance dz that each node moves along the arc is calculated using the above formula as (5.21, 5.21, 6.45, 6.45, 5.19, 5.19, 5.19, 6.43). Finally, by moving the highest point T of the arc along its arc by the distance dz, the transformed coordinates can be obtained. Figure 5 As shown in -(b), update the node data of the corresponding cell in the elements array.
[0042] Step 15: Create the mesh file. The mesh, after the transformations in steps 13 and 14, is now fully satisfactory, as shown below. Figure 5As shown in (c), create a three-dimensional patterned mesh INP file that can be used for simulation calculations according to the input format requirements of ABAQUS software.
[0043] The above description is merely a preferred embodiment of the present invention. These specific embodiments are different implementations based on the overall concept of the present invention, and the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for tire tread pattern modeling and finite element mesh generation based on ABAQUS, mainly including the following steps: The first step is to clean up the two-dimensional drawings of the early design of the tread pattern. According to the two-dimensional AutoCAD drawings of the early design of the tread pattern, the pattern drawing is output as a DXF file using the DXFOUT command. The second step is to extract the tread pattern outline curve. Based on the cleaned drawing from the first step, extract the tread outline curve from the drawing and output the outline curve as a separate DXF file. Before outputting the DXF file, place the upper and lower outline curves on different layers, and at the same time, translate the coordinates of the center point of the upper outline to the coordinate origin CP(0, 0). The third step is to generate control points for the contour boundary. First, set the number of discrete points N for the upper and lower contour curves. Discretize the contour boundary according to the number of control points N, while ensuring that the upper and lower contours have the same number of control nodes N. Next, calculate the lengths of the upper and lower parts of the tire tread, denoted as topLen and bottomLen, respectively. Then, calculate the discrete distance of the contour curve based on the contour length and the number of control points N. Finally, place the control nodes of the upper contour in the topNodes array variable and the control nodes of the lower contour in the btmNodes array variable. The array variables store a three-dimensional spatial coordinate point structure containing three variables: x, y, and z. The fourth step is to unfold the tread profile curve. Unfold the arc-shaped tread profile into a straight plane, calculate the length l of the tread profile, and obtain the coordinates of the starting point SP(0, 0) and the ending point EP(l, 0) of the unfolded straight line. The fifth step involves transforming the control points on the upper part of the tread profile. Following the operations in the second step, the center point coordinates of the tread profile are CP(0, 0). The control points on the upper part of the original profile are transformed onto the straight profile of the fourth step. The implementation method is as follows: First, iterate through each control point in the topNodes array of the third step to obtain the corresponding control point p(x, y). Then, calculate the curve length s from the center point coordinates of the profile to the position of point p. Thus, the coordinates of the point on the straight profile can be represented as p. ’ (s, 0), and finally store the calculated coordinates in the array variable topTemp; Step 6: Determine the positional relationships of the original contour. The specific implementation process is as follows: First, traverse the array variable btmNodes of the lower control points of the contour obtained in Step 3 to obtain the coordinates p(x, y). Then, record the position index of point p in the array as i. Through the array position indices i and i+1, obtain the corresponding coordinate points p1 and p2 in topNodes. Record vectors v1 = p - p1 and v2 = p1 - p2. Finally, calculate the magnitude ds of vector v1 and the angle from vector v1 to v2. By using the length ds and angle relative to the corresponding position of the upper curve of the contour That is, the positional relationship of the control points can be uniquely determined; Step 7: Transformation of the lower control points of the tread profile. The specific implementation process is as follows: First, reduce the length of the topTemp array calculated in step 5 by 1 to obtain two adjacent points p1(x, y) and p2(x, y), and denote the vector v = p2 - p1; then rotate the vector v clockwise. Get vector v ’ Then, point p1 is aligned with vector v. ’ Move the control point a distance ds in the direction it is in to obtain the coordinates of the lower part of the tread profile; finally, store the new coordinates in the btmTemp array; Step 8: Set the tread pattern pitch length. According to the tread pattern design requirements, set the pitch length pitchLen (mm). Step 9: Create a solid model of the tread profile. Based on the pitch length pitchLen in step 8, use the solid modeling commands built into the ABAQUS software to create a three-dimensional model of the tread profile. Step 10: Establish the tread pattern geometry model. Based on step 9, create the tread pattern grooves using the grooving command in solid modeling. Step 11: Generate the 3D pattern mesh. Use ABAQUS software to create a 3D pattern finite element mesh and output the node and element information to the INP file. Step 12: Set the outer diameter D (mm) of the tire tread. Based on the specific model and specifications of the tire, obtain its maximum outer diameter as D. Step 13: Transform the tread pattern mesh laterally along the tire tread. The specific implementation process is as follows: First, traverse each cell in the mesh, extract the coordinates of each node in the cell, and denot it as p(x, y, z). Set z to 0 in the cell node coordinates, so the node is denoted as p(x, y, 0). Second, calculate the horizontal distance dx and dy between point p and the contour center point CP. The angle between the straight line from point p along the y-axis and the flat surface is 90 degrees. Simultaneously, assume that the node coordinates to the right of the contour center point CP have positive values, and the node coordinates to the left of the contour center point CP have negative values. Then, according to the upper curve of the original tire tread contour, translate based on the distance from the contour center point CP to obtain the transformed reference node coordinates q(x, y, z). The movement rule is as follows: if the distance is positive, start from the center point CP and move a distance dx along the right side of the contour line; otherwise, start from the center point CP and move a distance dx along the left side of the contour line. Finally, calculate the normal vector n of the upper curve of the tread contour through the reference node q, and move the coordinate q a distance dy according to the vector n. After the movement, the coordinate p of the transformed element node p is obtained. ’ (x' ,y' ,z), and update the original element node coordinates, and store the elements after the node coordinates have been transformed in the elements array variable; Step fourteen: Transform the tread pattern along the longitudinal direction of the tire tread. First, based on the tire tread outer diameter D and the tread pitch length pitchLen, the arc angle of the tread pattern along the tire circumference can be obtained as follows: =2*pitchLen / D, the outer radius of the tire tread is R=D / 2; then iterate through the elements array in step thirteen, take out the coordinates of each node in the cell, denoted as p(x, y,z), and calculate its distance dy to the XZ coordinate plane, the radius of the arc where the point is located is R. ’ =R-dy; then calculate the distance from this point to the radius R. ’ Let dz be the horizontal distance from the highest point T(x, y, z) of the arc, and assume that the point is located at the highest point T(pitchLen / 2, 0, R). ’ The distance to the right is taken as a positive value, and the distance to the left of the highest point T of the arc is taken as a negative value; finally, based on the radius R of the arc... ’ dz `pitchLen` obtains the node coordinates after the node transformation. This coordinate is determined by the arc length `ds` along which the arc vertex `T` moves. `ds` is calculated using the following formula. ds= ; In the formula R ’ dz is the radius of the arc, and dz is the horizontal distance from the current node to the highest point T of the arc. It is the arc angle, and pitchLen is the pattern pitch length. It is also stipulated that if the distance is positive, it moves clockwise along the arc from the arc vertex T, and otherwise moves counterclockwise along the arc. The coordinates of the point after the movement are the nodes after the transformation, and the coordinate values of the original nodes are updated at the same time. Step 15: Create a mesh file. Create a 3D patterned mesh INP file that can be used for simulation calculations, according to the input format requirements of ABAQUS software.
2. The generation method according to claim 1, characterized in that: In the first step, unnecessary information such as annotation text and annotation lines defined in the drawing is removed, while retaining the geometric elements related to the pattern.
3. The generation method according to claim 1, characterized in that: In the third step, based on the axisymmetric characteristics of the tread pattern outline, the right half of the outline is taken, and the complete outline boundary control points are obtained by mirroring the center point of the outline.
4. The generation method according to claim 1, characterized in that: The generation method is embedded into finite element simulation software through secondary development programming.
5. The use of the generation method according to any one of claims 1-4 for numerical simulation of tire mechanical properties and tire performance simulation.