CN110362870A - A Finite Element Modeling Method for Complex Pattern Tires Based on Hexahedral Meshing - Google Patents

Abstract

The invention discloses a finite element modeling method for complex pattern tires divided by hexahedral grid, comprising the steps of: S1, drawing a two-dimensional cross-sectional geometric model of the tire, performing tire segmentation processing in advance according to the characteristics of tread blocks, and recording the scores The total number of segments is N; S2. Project the geometric feature points of a segment of blocks to a two-dimensional plane grid through segment expression; S3. Project the constructed two-dimensional plane grid nodes to the tire inner cavity surface, and pass the grid nodes Layer-by-layer stretching generates a section of three-dimensional tread and pattern block meshes; S4, draws a two-dimensional plane mesh of the sidewall, rotates it into a three-dimensional mesh according to the corresponding angle and merges it with the mesh nodes of the tread; S5, generates a section The three-dimensional tire mesh is repeatedly rotated and copied around the central axis of the tire to generate N segments, and the finite element model of the complex pattern tire divided by the hexahedral mesh is obtained. In the present invention, the connection between the complex block and the tread adopts the integrated modeling of grids with common nodes, which is more accurate and has higher solution efficiency.

Description

A Finite Element Modeling Method for Complex Pattern Tires Based on Hexahedral Meshing

technical field

The invention relates to a tire finite element modeling method, in particular to a complex pattern tire finite element modeling method that can realize hexahedral grid division, and can more accurately analyze the force analysis of complex pattern tires.

Background technique

As an important component of the vehicle, the tire not only supports the body load, transmits the driving force and steering force to the ground, but also plays the role of buffering and shock absorption. Tread pattern is one of the most important parameters of a tire. In order to meet the requirements of different vehicles driving on different roads, tread patterns are often designed into various shapes, such as ordinary patterns, mixed patterns and off-road patterns. A large number of practical experience and test data show that the pros and cons of the tire pattern design have a significant impact on the driving braking performance, rolling resistance, steering performance and wear resistance of the tire.

In traditional tire production, to test whether the new pattern tire design scheme is reasonable, it generally needs to go through the process from design to production to obtain sample tires, and then carry out test inspection. This kind of empirical design while testing and designing often consumes a lot of time and money. In recent years, with the popularization and application of finite element simulation method, tire design and test can be completed in simulation software, which greatly improves the design and test efficiency of patterned tires. Then, due to the complexity of the tire pattern model, the existing finite element modeling methods for complex pattern tires mainly adopt the separate modeling method, that is, the whole regular tire without the pattern blocks is taken as a whole module, and the pattern blocks are used as sub-modules. In the finite element mesh modeling, the whole module grid of the regular tire with the pattern blocks removed is drawn first, and then the sub-module grid of the pattern blocks is drawn. Since the grids between the overall module and the sub-modules are not connected by a common node, the grids of the pattern block sub-modules need to be "pasted" on the tread in the form of binding and fixing. When the finite element solution is performed, the overall tire model and the pattern block sub-model are also solved separately. That is, firstly use the tire overall model for calculation to obtain the node displacement or stress on the boundary surface of the tire overall corresponding to the pattern block sub-model, and apply the contact boundary condition between the ground and the pattern block, and then drive the pattern based on this. The block sub-model is solved, and finally the analysis results of the entire tread tire are obtained.

The existing method for finite element modeling of complex pattern tires adopts the overall model and sub-model. Since the pattern block and the tread are not connected by a common node, that is, the overall tire model and the pattern block sub-model have different contact boundary conditions, so the existing method In theory, it is unreasonable; at the same time, the modeling method through the pattern block sub-model needs to add relevant binding contact between the pattern block and the tread, which increases the calculation work, so the simulation calculation efficiency will also decrease. Therefore, in view of the above-mentioned defects, the present invention proposes a hexahedral mesh division method suitable for finite element modeling of complex pattern tires with common grid nodes, so as to perform more accurate and efficient simulation analysis on the performance of complex pattern tires.

SUMMARY OF THE INVENTION

In order to solve the problems of inaccurate finite element model and complex modeling of existing complex pattern tires, the present invention proposes a hexahedral mesh division finite element modeling method for complex pattern tires. The purpose of the present invention is to improve the accuracy of the finite element model of the tire with complex pattern and the efficiency of simulation calculation, so as to carry out more accurate and efficient simulation analysis on the performance of the tire with complex pattern.

The hexahedral mesh has obvious advantages over other element meshes in terms of calculation accuracy, number of divided meshes and anti-distortion degree. Therefore, the most widely used hexahedral mesh is used for meshing of tires with complex patterns. Among them, the pattern blocks and the tread are connected by grid co-nodes, which can not only obtain an accurate finite element model consistent with the real object; at the same time, because the binding contact of the pattern blocks on the tread is reduced, the efficiency of the simulation calculation is also improved. The finite element simulation analysis results of complex tread tires can be quickly obtained.

The object of the present invention is realized by at least one of the following technical solutions:

A finite element modeling method for complex pattern tires divided by hexahedral mesh, comprising the steps of:

S1. Draw a two-dimensional cross-sectional geometric model of the tire, perform tire segmentation processing in advance according to the characteristics of the tread blocks, and record the total number of segments N;

S2. Set the coordinate points for the key geometric features of the tread blocks, and project the geometric feature points of a section of blocks to a two-dimensional plane grid through segmented expression;

S3. Project the constructed two-dimensional plane mesh nodes onto the inner surface of the tire, and generate a section of three-dimensional tread and pattern block meshes by layer-stretching the mesh nodes;

S4, draw the two-dimensional plane grid of the sidewall, rotate it into a three-dimensional grid according to the corresponding angle and merge with the grid node of the tread in step S3;

S5 , take the generated three-dimensional tire mesh with the central axis of the tire as the rotation axis, repeat the rotation and duplication to generate N segments, and finally obtain the complex pattern tire finite element model divided by the hexahedral mesh.

Further, in step S1, tire segmentation processing is carried out in advance according to the complex pattern shape characteristics and arrangement rules on the tire surface. The principle of segmentation processing is that the arrangement rules and shapes of the blocks in each segment are consistent along the tire circumferential direction, and record the tire's shape. The total number of segments N.

Further, when the blocks in the tire are segmented, the central axis of the tire is used as the rotation axis. If the total number of tire segments is N, the rotation angle corresponding to the blocks in each segment is 360°/N.

Further, in step S2, according to the relevant geometric dimensions of the actual patterned tire, the finite element meshing software is used to obtain the coordinates of the key geometric dimensions of the tread and the pattern block, and the key geometric point of a section of the pattern block is projected to the center axis of the tire. Parallel 2D planar grid.

Further, in step S3, the tire inner cavity surface is a two-dimensional curved surface generated by rotating the contour line 360° around the tire center axis in the two-dimensional model of the tire cross-section in step S1, and the two-dimensional curved surface is attached to the tire inner cavity surface. combine.

Further, in step S4, first complete the three-dimensional grid modeling of the tread blocks of a section, and then perform the two-dimensional grid modeling of the sidewall, wherein the rotation axis of the two-dimensional grid of the sidewall is the central axis of the tire, and the corresponding rotation angle is based on The total number of segments is calculated as 360°/N.

Further, in step S5, first complete the three-dimensional mesh modeling of a section of the patterned tire, then copy and rotate the original section of the three-dimensional mesh model, so as to generate the three-dimensional mesh model of the second section, wherein the rotation axis is the tire. The central axis, the rotation angle is 360°/N, and the pattern tires with the total number of segments are generated by successively copying and rotating, and then the complete finite element model of the complex pattern tire with hexahedral mesh division can be obtained.

Compared with the prior art, the present invention has the following advantages and effects:

In the method of the present invention, the hexahedral grid connection between the complex pattern block and the tread adopts a common node connection method, which is consistent with the actual complex pattern tire structure, the finite element model is more accurate, and can more accurately express the actual stress condition of the complex pattern tire . At the same time, since the blocks and the grid of the tread are connected at the same node, there is no need for additional blocks to perform the contact binding calculation on the tread, so the efficiency of the simulation calculation can be better improved.

Description of drawings

FIG. 1 shows a two-dimensional schematic diagram of the tire cross-section of the present invention.

Figure 2 shows a schematic diagram of the process of acquiring key geometric points of a two-dimensional grid of a tire of the present invention, wherein Figure 2 (a) is a schematic diagram of key feature points of a pattern block; Figure 2 (b) is a schematic diagram of key geometric points of a two-dimensional grid.

FIG. 3 shows a schematic diagram of the process of projecting the two-dimensional grid nodes of the present invention onto the surface of the inner cavity of the tire.

FIG. 4 is a schematic diagram showing the drawing direction of the three-dimensional grid generated by the two-dimensional grid of the present invention.

FIG. 5 shows a schematic diagram of the two-dimensional mesh layered stretching process of the present invention.

Figures 6(a)-6(c) respectively show the front, left and three-dimensional schematic diagrams of the sidewall grid and the tread grid of the present invention combined.

FIG. 7 shows a schematic diagram of the process of duplicating and rotating a segmented 3D mesh according to the present invention.

FIG. 8 shows a schematic diagram of a tire with a complex pattern after the modeling of the present invention is completed.

In the figure: 1-block; 2-tread layer; 3-belt layer; 4-inner liner.

Detailed ways

The specific implementation of the present invention will be further described below with reference to the accompanying drawings, which are only preferred embodiments of the present invention, but the implementation and protection scope of the invention are not limited thereto.

Taking a certain type of off-road vehicle pattern tire as an example, a finite element modeling method of complex pattern tire with hexahedral mesh division includes steps:

S1, draw a tire two-dimensional cross-section geometric model, carry out tire segmentation processing in advance according to the characteristics of tread blocks, and write down the total number of segments N, in this embodiment N is 46;

S2. Set the coordinate points for the key geometric features of the tread blocks, and project the geometric feature points of a section of blocks to a two-dimensional plane grid through segmented expression;

S3. Project the constructed two-dimensional plane mesh nodes onto the inner surface of the tire, and generate a section of three-dimensional tread and pattern block meshes by layer-stretching the mesh nodes;

S4, draw the two-dimensional plane grid of the sidewall, rotate it into a three-dimensional grid according to the corresponding angle and merge with the grid node of the tread in step S3;

S5 , take the generated three-dimensional tire mesh with the central axis of the tire as the rotation axis, repeat the rotation and duplication to generate N segments, and finally obtain the complex pattern tire finite element model divided by the hexahedral mesh.

Specifically, in step S1, tire segmentation processing is performed in advance according to the complex pattern shape characteristics and arrangement rules on the tire surface. The principle of segmentation processing is that the arrangement rules and shapes of the blocks in each segment along the tire circumferential direction are consistent, and the tires are recorded. The total number N of segments is 46 in this embodiment.

Specifically, when the blocks in the tire are segmented, the central axis of the tire is used as the rotation axis. If the total number of tire segments is N, the rotation angle corresponding to the blocks in each segment is 360°/N.

Specifically, in step S2, according to the relevant geometric dimensions of the actual patterned tire, the finite element meshing software is used to obtain the coordinates of the key geometric dimensions of the tread and pattern blocks, and the key geometric points of a section of pattern blocks are projected to the center of the tire. A 2D planar grid with parallel axes.

Specifically, in step S3, the tire inner cavity surface is a two-dimensional curved surface generated by rotating the contour line in the two-dimensional model of the tire cross-section by 360° around the central axis of the tire in step S1, and the two-dimensional curved surface and the tire inner cavity surface are fit.

Specifically, in step S4, first complete the three-dimensional mesh modeling of a section of tread blocks, and then carry out the two-dimensional mesh modeling of the sidewall, wherein the rotation axis of the two-dimensional mesh of the sidewall is the central axis of the tire, and the corresponding rotation angle Calculated as 360°/N based on the total number of segments.

Specifically, in step S5, first complete the 3D mesh modeling of one section of the tread tire, and then copy and rotate the original section of the 3D mesh model to generate the 3D mesh model of the second section, wherein the axis of rotation is The center axis of the tire, the rotation angle is 360°/N, and the pattern tire with the total number of segments is generated by copying and rotating in turn, and then the complete finite element model of the complex pattern tire divided by the hexahedral mesh can be obtained.

The modeling method provided by the above embodiment will be further described below with reference to the accompanying drawings.

Figure 1 shows a two-dimensional schematic diagram of the tire cross-section of the present invention, wherein since the tire pattern is a left-right symmetrical structure, half of the tire geometric structure is used as the finite element mesh modeling. After the modeling is completed, the complete finite element can be obtained by symmetrical replication. Model. According to the pattern characteristics of the tire, the pattern block is initially divided into 46 pattern segments with the central axis of the tire as the rotation axis, that is, the angle occupied by each pattern block is 360°/46=7.826°. Therefore, on the basis of the two-dimensional schematic diagram of the tire cross-section, it is necessary to first establish a finite element model of the tire and the block.

Fig. 2 is a schematic diagram showing the process of obtaining key geometric points of a two-dimensional grid of a tire of the present invention, wherein the key points are coordinate selection points according to the actual shape and size of the tread pattern, and the obtained key points are projected to the corresponding parallel on a 2D planar grid of the tire's central axis.

3 is a schematic diagram showing the process of projecting the two-dimensional grid nodes of the present invention to the surface of the tire cavity, wherein the tire cavity surface is a curved surface obtained by rotating the innermost contour line in the two-dimensional tire section in FIG. 1 by 360° around the center axis of the tire , the rotated curved surface fits with the curved surface of the tire cavity. The 2D mesh node is projected onto the cavity surface to obtain the same surface and shape as the tire. After projection, a 3D mesh is obtained by extruding the 2D mesh layerwise.

FIG. 4 is a schematic diagram showing the drawing direction of the three-dimensional grid generated by the two-dimensional grid of the present invention. Among them, in order to obtain a finite element model consistent with the shape of the tire, the center axis of the tire is taken as the starting point to stretch along the radial direction of the tire. When stretching, each row of nodes is stretched in a certain direction at the same time, and the height of each layer should be stretched according to the actual tire structure, and the multi-layer structure of the tire can be obtained by layered stretching.

FIG. 5 shows a schematic diagram of the two-dimensional mesh layered stretching process of the present invention. In this embodiment, the tire structure is divided into blocks 1 , tread layer 2 , belt layer 3 , and inner liner 4 . The specific tire layer structure should be carried out according to the actual tire. In addition, shell elements can be inserted in the mesh nodes to obtain equivalent structures such as plies.

After generating a section of three-dimensional tread and pattern mesh, a two-dimensional mesh of the sidewall is generated. In general, the shape of the sidewall is regular, and it is only necessary to rotate and stretch the two-dimensional plane grid at a corresponding angle (the angle in this embodiment is 7.826°) with the center axis of the tire as the rotation axis, and the grid nodes on the sidewall edge are connected to the tire. The mesh nodes at the edge of the face are merged to obtain the three-dimensional tire mesh of the section shown in Fig. 6(a)-Fig. 6(c).

7 is a schematic diagram showing the process of duplicating and rotating a segmented tire 3D mesh in the present invention, wherein duplication and rotation are performed in a segment of the tire 3D mesh after the above steps are completed, and the number of segments for duplication and rotation has already been set at the beginning. Sure. In this example, the tread tire is divided into 46 segments, so the rotation angle of each segment is 7.826°. After the copying and rotation are completed, since there may be a small gap between each 3D mesh, it is necessary to merge the mesh nodes one step at this time. Finally, the finite element model of the complex pattern tire after modeling as shown in Figure 8 can be obtained. .

To sum up, in the finite element modeling of tires with complex patterns, the present invention uses hexahedral meshes to divide the patterned tires into uniformly shaped segments based on the characteristics and laws of the tread pattern in the finite element modeling of tires with complex patterns; more importantly The main purpose is to model the complex block mesh and the tread mesh with the same node. Compared with the existing finite element modeling method, the complex pattern block mesh and the carcass mesh need to be modeled separately, the finite element model constructed by the present invention is more consistent with the actual complex pattern tire structure, and the finite element model is more accurate. At the same time, due to the common node connection between the block grid and the tread grid in the present invention, there is no need for additional block grid and tread grid to perform contact binding calculation, so the efficiency of simulation calculation can be better improved . Therefore, the present invention can better solve the problem of inaccurate finite element modeling of the existing complex pattern tires, and can efficiently obtain the simulation analysis results of the complex pattern tires.

It should be noted that although the implementation of the present invention has been described in detail with reference to examples, those skilled in the art will readily understand that any modifications made without departing from the spirit and principles of the present invention set forth in the appended claims , replacement and improvement, etc., should all be included within the protection scope of the present invention.

Claims (7)

1. the intricate detail tire finite element modeling method that a kind of hexahedral mesh divides, which is characterized in that comprising steps of

S1, tire two-dimensional section geometrical model is drawn, tire segment processing is carried out according to tread block feature in advance, and write down Segmented general number N；

S2, coordinate points setting is carried out to tread block key geometrical characteristic, by partitioned representation by the geometry of one section of pattern block Projecting characteristic points are to two-dimensional surface grid；

S3, the two-dimensional surface grid node of building is projected to tyre cavity face, is layered by grid node and stretches generation one Duan Sanwei tyre surface and pattern block grid；

S4, sidewall two-dimensional surface grid is drawn, rotates to be three-dimensional grid and grid section with tyre surface in step S3 by corresponding angle Point merges；

S5, one section of three-dimensional tire grid will have been generated using tire centerline axis as rotary shaft, has repeated to rotate and duplication generates N Section, the final intricate detail tire finite element model for obtaining hexahedral mesh and dividing.

2. intricate detail tire finite element modeling method according to claim 1, which is characterized in that in step S1, foundation Surface of tyre intricate detail features of shape and arrangement regulation carry out tire segment processing in advance, and the principle of segment processing is in every section Pattern block is consistent along the arrangement regulation and shape of tire circumferential direction, and records the segmented general number N of tire.

3. intricate detail tire finite element modeling method according to claim 2, which is characterized in that decorative pattern in the tire Using tire centerline axis as rotary shaft when block segment processing, if tire segmentation total number is N sections, in every section corresponding to pattern block Rotation angle be 360o/N.

4. intricate detail tire finite element modeling method according to claim 1, which is characterized in that in step S2, foundation Practical rib tire correlation geometric dimension carries out tyre surface and pattern block key geometric dimension using finite element mesh generation software Coordinate takes a little, and the crucial geometric point of one section of pattern block is projected to the two-dimensional surface grid parallel with tire centerline axis.

5. intricate detail tire finite element modeling method according to claim 1, which is characterized in that described in step S3 Tyre cavity face by lines of outline in tire cross-section two dimensional model in step S1 around tire centerline axis rotation 360o generate Two-dimensional Surfaces, the Two-dimensional Surfaces and tyre cavity face paste are closed.

6. intricate detail tire finite element modeling method according to claim 1, which is characterized in that first complete in step S4 It is modeled at one section of tread block three-dimensional grid, then carries out sidewall two-dimensional grid modeling, wherein sidewall two-dimensional grid rotary shaft For tire centerline axis, the corresponding angle that rotates is figured out according to segmented general as 360o/N.

7. intricate detail tire finite element modeling method according to claim 1, which is characterized in that first complete in step S5 At one section in rib tire of three-dimensional grid modeling, then replicates and rotate original one section of three-dimensional grid model, generated with this The three-dimensional grid model of second segment, wherein rotary shaft is tire centerline axis, and rotation angle is 360o/N, successively replicates and rotates The rib tire that total number of segment is N is generated, the intricate detail tire finite element model that complete hexahedral mesh divides can be obtained.