A multi-layer rod end joint meshing method

Abstract

The present invention discloses a multi-layer rod end joint mesh division method, comprising: dividing the multi-layer rod end joint into an axisymmetric part and a non-axisymmetric part; performing two-dimensional section processing on the axisymmetric part and meshing the two-dimensional section; rotating the two-dimensional section mesh after meshing into a three-dimensional mesh, completing the meshing of the axisymmetric part, and obtaining a three-dimensional mesh model of the axisymmetric part; performing geometric model processing on the non-axisymmetric part, and meshing the non-axisymmetric part after the geometric model processing, and obtaining a three-dimensional mesh model of the non-axisymmetric part; assembling and binding the axisymmetric three-dimensional mesh model with the three-dimensional mesh model of the non-axisymmetric part, and completing the meshing of the multi-layer rod end joint; the present invention improves the analysis accuracy and efficiency by dividing the rod end joint into two parts, axisymmetric and non-axisymmetric, and performing meshing work respectively, and combining outer dense inner sparse and free surface processing.

Description

Technical Field

[0001] The present invention belongs to the technical field of mesh division of finite element analysis, and in particular relates to a multi-layer rod end joint mesh division method. Background Art

[0002] A rod end joint is a flexible connection installed at the end of a rod, including a connecting rod joint, a traction rod joint, and a rotor flexible connection. It is widely used in control and power transmission systems in fields such as rail transportation and aerospace. Rod end joints are usually composed of a core shaft, a spacer, an external joint, and rubber vulcanization. According to the structural form, they are divided into single-layer rod end joints and multi-layer rod end joints. Among them, multi-layer rod end joints refer to metal rubber vulcanized rod end joints containing multiple layers of rubber and multiple layers of spacers. Multi-layer rod end joints have better multi-axis load-bearing capacity and can simultaneously withstand large radial loads, axial loads, torsional loads, deflection loads and other composite loads.

[0003] During the development of multi-layer rod ends, assessing the fatigue life of the rod ends is a critical consideration. Both experimental and finite element simulation methods are used for this purpose. Given the time and cost associated with experimental methods, finite element simulation is becoming increasingly popular. Using finite element simulation in place of experimental testing during the preliminary research and design phases reduces the number of trials and tests, improves the first-time design success rate for rod ends, shortens the development cycle, and reduces development costs.

[0004] The difficulty in simulating the fatigue life of multi-layer rod-end joints lies in the accuracy and efficiency of the analysis. Meshing is crucial for ensuring both accurate calculation results and improved efficiency. Conventional meshing methods create separate 2D and 3D meshes for each rubber layer and each spacer layer. This method is inefficient for these multi-layer rod-end joints, especially for rotor flexible connection rod-end joints with more than 30 layers of rubber and spacers, where meshing alone can take a week. Therefore, conventional meshing methods struggle to achieve a balanced balance between simulation accuracy and efficiency for these multi-layer rod-end joints. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a multi-layer rod end joint mesh division method, which solves the problem of low efficiency and low precision of rod end joint mesh division by dividing the rod end joint into axisymmetric and non-axisymmetric parts and performing mesh division respectively.

[0006] The technical solutions adopted by the present invention to solve the problems of the prior art are as follows:

[0007] A multi-layer rod end joint meshing method is provided, comprising:

[0008] Dividing the multi-layer rod end joint into an axisymmetric part and an asymmetric part, wherein the axisymmetric part includes multiple layers of rubber and a spacer, and the asymmetric part includes a core shaft and an outer joint;

[0009] Performing two-dimensional cross-section processing on the axisymmetric portion and meshing the two-dimensional cross-section;

[0010] The two-dimensional cross-section mesh after meshing is rotated into a three-dimensional mesh, the meshing of the axisymmetric part is completed, and a three-dimensional mesh model of the axisymmetric part is obtained;

[0011] Performing geometric model processing on the non-axisymmetric part, and meshing the non-axisymmetric part after the geometric model processing to obtain a three-dimensional mesh model of the non-axisymmetric part;

[0012] The axisymmetric three-dimensional mesh model and the non-axisymmetric three-dimensional mesh model are assembled and bound to complete the multi-layer rod end joint mesh division.

[0013] Furthermore, the two-dimensional cross-section processing includes extracting two-dimensional cross-sections of the multi-layer rubber and spacers of the axisymmetric portion, and the extracted portion is half of the cross-section to the right of the center line.

[0014] Furthermore, the rotation is based on Hypermesh software and specifically includes the following steps:

[0015] S1. Use the spin command to rotate the 2D cross-section mesh 360 degrees around the X-axis to obtain a 3D mesh model of half the axisymmetric part.

[0016] S2. Use the reflect command to map the half of the three-dimensional mesh model to the YZ plane to obtain a complete three-dimensional mesh model;

[0017] S3. Then, the two halves of the mapped three-dimensional mesh model are subjected to common node processing on the YZ plane to obtain a three-dimensional mesh model of the axisymmetric part.

[0018] Furthermore, the geometric model processing is based on Proe software, and the geometric model processing simplifies the core shaft and the external joint of the non-axisymmetric part into a quarter of the core shaft and the external joint.

[0019] Furthermore, the meshing of the non-axisymmetric part after the geometric model processing is performed based on Hypermesh software, including:

[0020] T1. After simplifying the geometric model, export the quarter core shaft and external joint in STP format. Import this file into Hypermesh software for surface meshing and 3D meshing to create a 3D mesh model of the quarter core shaft and external joint.

[0021] T2. The three-dimensional mesh model of the quarter mandrel and the outer joint is divided into four parts using the reflect command and mapped to the XY plane and YZ plane to obtain four quarter three-dimensional mesh models;

[0022] T3. Perform common node processing on the four quarter three-dimensional mesh models on the XY plane and the YZ plane.

[0023] Furthermore, the two-dimensional cross section is meshed, including: dividing the two-dimensional cross section into multiple parts from the inside out, and meshing according to the principle of dense outer part and sparse inner part; specifically including the following steps:

[0024] Obtaining the outermost basic control point on the two-dimensional cross section;

[0025] Obtaining the distance from the outermost basic point to the inner edge of the two-dimensional cross section along the X-axis direction, and obtaining a plurality of basic control points located on the two-dimensional cross section according to the distance ratio;

[0026] Taking the multiple basic control points as starting points, respectively draw basic control lines to divide the two-dimensional cross section into multiple areas;

[0027] The multiple regions are divided into grids respectively.

[0028] Preferably, the distance from the outermost basic control point to the inner edge of the two-dimensional cross-section along the X-axis direction is a vertical distance.

[0029] Furthermore, the distance ratio is: the ratio of the vertical distances from the multiple basic control points along the X-axis direction to the inner edge of the two-dimensional section to the vertical distance from the outermost basic control point along the X-axis direction to the inner edge of the two-dimensional section.

[0030] Specifically, the number of the multiple basic control points is 2, namely the first basic control point and the second basic control point. The vertical distance from the outermost basic control point to the inner edge of the two-dimensional cross-section along the X-axis direction is recorded as d, the vertical distance from the first basic control point to the inner edge of the two-dimensional cross-section along the X-axis direction is recorded as e, and the vertical distance from the second basic control point to the inner edge of the two-dimensional cross-section along the X-axis direction is recorded as f, where e=0.8d and f=0.6d.

[0031] Furthermore, a first auxiliary point located above the outer edge on the two-dimensional cross-section and a second auxiliary point located below the outer edge on the two-dimensional cross-section are obtained, and the first auxiliary point and the second auxiliary point are connected to form an auxiliary line, and the auxiliary line forms a basic angle with the Y-axis.

[0032] Furthermore, basic control lines are respectively made with the multiple basic control points as starting points, and the angles formed between the basic control lines and the Y axis are proportional to the basic angles.

[0033] Specifically, the number of basic control lines is 2, namely the first basic control line and the second basic control line. The basic angle is denoted as a, the angle formed by the first basic control line and the Y-axis is denoted as b, and the angle formed by the second basic control line and the Y-axis is denoted as c, where b=0.75a and c=0.45a.

[0034] Furthermore, the grid unit sizes among the multiple regions are in proportional relationship.

[0035] Specifically, the number of the multiple regions is 3, namely a mesh refinement region, a transition region and a mesh coarsening region. The mesh unit size ratio of the transition region to the mesh refinement region is 1.3-1.6, and the mesh unit size ratio of the mesh coarsening region to the mesh refinement region is 1.6-2.

[0036] Preferably, the ratio of the number of grid layers in the coarsening grid area to the number of grid layers in the refining grid area is 0.5-0.7.

[0037] Furthermore, meshing the two-dimensional cross section further includes processing a free surface between the rubber and the spacer, the free surface including a sharp corner region, the sharp corner region including at least a first arc segment and a second arc segment intersecting each other, a first straight line segment intersecting the second arc segment, and a third arc segment intersecting the other end of the first straight line segment;

[0038] performing a passivation process on the sharp corner area of ​​the free-form surface, wherein the passivation process comprises dragging the intersection point of the second arc segment and the first arc segment to the midpoint of the first arc segment;

[0039] The free-form surface is segmented based on the midpoint of the first arc segment, the intersection of the second arc segment and the first straight line segment, and the midpoint of the third arc segment as basic control points;

[0040] Extending a basic control line from the basic control point toward the rod end joint body, thereby cutting the surface area located inside the free-form surface on the two-dimensional cross section into a plurality of closed or open sub-surface areas through the basic control line;

[0041] The sub-face regions are respectively subjected to tetrahedral grid layout to form a full-section grid layout.

[0042] Furthermore, when extending the basic control line from the midpoint of the first arc segment, the following steps are specifically included:

[0043] Get the midpoint of the first arc segment and the inner endpoint of the free surface, and the midpoint of the second arc segment, connect the midpoint and endpoint of the first arc segment to form a first auxiliary line; connect the midpoint of the second arc segment and the midpoint of the first arc segment to form a second auxiliary line; the first auxiliary line and the second auxiliary line form an angle α, and use the midpoint of the first arc segment as the starting point to draw a straight line with an angle of α / 2 as the first basic control line.

[0044] Furthermore, when extending the basic control line from the midpoint of the third arc segment, the following steps are specifically included:

[0045] Obtain the midpoint of the third arc segment and the intersection of the third arc segment and the first straight line segment, connect the midpoint of the third arc segment and the intersection of the third arc segment and the first straight line segment to form a third auxiliary line; with the midpoint of the third arc segment as the starting point, make a fourth auxiliary line perpendicular to the third arc segment; the third auxiliary line and the fourth auxiliary line form an angle β, with the midpoint of the third arc segment as the starting point, make a straight line with an angle of β / 3 as the second basic control line.

[0046] Furthermore, it also includes taking the endpoint of the second basic control line as the starting point, making a third basic control line parallel to the first straight line segment, and intersecting with the first basic control line.

[0047] Furthermore, it also includes taking the intersection of the second arc segment and the first straight line segment as the starting point, making a fourth basic control line parallel to the second basic control line, and intersecting with the third basic control line.

[0048] Furthermore, it also includes taking the intersection of the first basic control line and the third basic control line as the starting point, connecting the midpoint of the second arc segment to form a fifth auxiliary line; taking the intersection of the third basic control line and the fourth basic control line as the starting point, connecting the midpoint of the fifth auxiliary line and extending it to the first basic control line to form a fifth basic control line.

[0049] Preferably, before cutting the surface region located inside the free-form surface on the two-dimensional cross section into a plurality of closed or open sub-surface regions using the basic control line, the auxiliary line is deleted.

[0050] Furthermore, it also includes a second straight line segment, which intersects with the first arc segment.

[0051] Furthermore, the passivation process includes: dragging the intersection point of the second straight line segment and the first arc segment to the end point of the first arc segment located outside the free surface.

[0052] The beneficial effects are as follows:

[0053] 1. By dividing the rod end joint into axisymmetric and non-axisymmetric structures and performing mesh division separately, the division efficiency is improved;

[0054] 2. By using a dense outer and sparse inner grid division method, the grid size of the internal non-critical areas is gradually reduced to control the overall grid size, which not only ensures the calculation accuracy but also improves the calculation efficiency;

[0055] 3. Free-form surfaces, especially those containing sharp corners, are meshed. The accuracy of the stiffness calculation process in the sharp corners is improved through passivation. The free-form surfaces are better cut into regions through segmentation, making the meshing of the free-form surfaces more reasonable. This further improves the accuracy of the subsequent finite element analysis and stiffness calculation of the free-form surfaces and improves the calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a flow chart of the grid division method of this embodiment;

[0057] Figure 2 is the three-dimensional model of the rod end joint of this embodiment;

[0058] Figure 3 is a two-dimensional cross-section of the axisymmetric portion of this embodiment;

[0059] Figure 4 A mesh division diagram of a two-dimensional cross section of the axisymmetric part of this embodiment;

[0060] Figure 5 is a three-dimensional mesh model of the axisymmetric part of this embodiment;

[0061] Figure 6 is a three-dimensional model of the non-axisymmetric part of this embodiment;

[0062] Figure 7 This is a three-dimensional grid division diagram after the non-axisymmetric part of this embodiment is divided into one quarter;

[0063] Figure 8 This is a three-dimensional grid division diagram of the non-axisymmetric part after quarter-portion mapping in this embodiment;

[0064] Figure 9 The overall three-dimensional mesh model of the rod end joint after axisymmetric and non-axisymmetric binding in this embodiment;

[0065] Figure 10 This is a flow chart of the outer dense and inner sparse grid division method of this embodiment;

[0066] Figure 11 This is a schematic diagram of the division of the multi-layer metal rubber in this embodiment;

[0067] Figure 12 This is a schematic diagram of the area division of the multi-layer metal rubber in this embodiment;

[0068] Figure 13 This is a schematic diagram of the area division of the multi-layer metal rubber in this embodiment;

[0069] Figure 14 This is a schematic diagram showing the number of layers and sizes of the multi-layer metal rubber grid in this embodiment;

[0070] Figure 15 This is a flow chart for dividing the free surface of the rod end joint in this embodiment;

[0071] Figure 16 Schematic diagram of the rod end joint structure of this embodiment;

[0072] Figure 17 This is an enlarged view of the free surface of the rod end joint rubber and spacer structure of this embodiment;

[0073] Figure 18 This is the free-form surface line segment position diagram of this embodiment;

[0074] Figure 19 This is a diagram of the segmented points of the free-form surface of this embodiment;

[0075] Figure 20 This is a schematic diagram of obtaining auxiliary lines of the free-form surface in this embodiment;

[0076] Figure 21 This is a schematic diagram of obtaining the basic control lines of the free-form surface in this embodiment;

[0077] Figure 22 This is a schematic diagram of meshing of the free-form surface without deleting auxiliary lines in this embodiment;

[0078] Figure 23 Schematic diagram of free-form surface mesh division in this embodiment;

[0079] In the figure: 1: core shaft, 2: spacer, 3: rubber, 4: external joint, 5: screw part of external joint, 6: end face of external joint, 7: outer surface of outermost rubber layer, 8: inner surface of innermost rubber layer, 9: inner circular surface of external joint inner hole, 10: outer circular surface of core shaft. DETAILED DESCRIPTION

[0080] The present invention will be further described below in conjunction with specific embodiments.

[0081] like Figure 1 As shown, this embodiment provides a multi-layer rod end joint meshing method, including:

[0082] Dividing the multi-layer rod end joint into an axisymmetric part and an asymmetric part, wherein the axisymmetric part includes multiple layers of rubber and a spacer, and the asymmetric part includes a core shaft and an outer joint;

[0083] Performing two-dimensional cross-section processing on the axisymmetric portion and meshing the two-dimensional cross-section;

[0084] The two-dimensional cross-section mesh after meshing is rotated into a three-dimensional mesh, the meshing of the axisymmetric part is completed, and a three-dimensional mesh model of the axisymmetric part is obtained;

[0085] Performing geometric model processing on the non-axisymmetric part, and meshing the non-axisymmetric part after the geometric model processing to obtain a three-dimensional mesh model of the non-axisymmetric part;

[0086] The axisymmetric three-dimensional mesh model and the non-axisymmetric three-dimensional mesh model are assembled and bound to complete the multi-layer rod end joint mesh division.

[0087] like Figure 2 The three-dimensional model of the rod end joint is shown. By analyzing its structural characteristics, the rod end joint is divided into two parts, Z and F, which are axisymmetric and non-axisymmetric. The axisymmetric part includes the rubber 3 and the spacer 2, and the non-axisymmetric part includes the core shaft 1 and the external joint 4. The external joint 4 also includes the screw part 5 of the external joint and the end face 6 of the external joint.

[0088] like Figure 3 As shown, the two-dimensional cross section of the rubber 3 and the spacer 2 of the axisymmetric part Z is extracted and a dwg file is generated. The CAD software is used for processing. Considering the left-right symmetry, the half cross section to the right of the center line is taken, which is Figure 3 .

[0089] like Figures 3 and 4 As shown, the two-dimensional cross-section of the axisymmetric part Z is exported as a dxf file and imported into the Hypermesh software for meshing to form a number of meshes W divided by lines.

[0090] like Figure 5 As shown, the completed Figure 4 The two-dimensional cross-sectional mesh shown in the figure is rotated 360 degrees around the X axis using the spin command in the Hypermesh software to obtain a three-dimensional mesh model of the half of the axisymmetric part; then, the half of the three-dimensional mesh model is mapped to the YZ plane using the reflect command to obtain a complete three-dimensional mesh model; the nodes of the two halves of the three-dimensional mesh model on the YZ plane are then processed as common nodes to obtain the following: Figure 5 The 3D mesh model of the axisymmetric section Z is shown.

[0091] like Figure 6As shown, the core shaft 1 and the external joint 4 of the non-axisymmetric part F are processed by Proe software to perform geometric model processing, and the symmetry of the core shaft 1 and the external joint 4 of the non-axisymmetric part F is analyzed. The processing in this embodiment is to cut them, including one quarter of the whole, and mesh the one quarter geometric model.

[0092] The processed geometric models of the core shaft 1 and the external joint 4 of the non-axisymmetric part F are exported as stp format files and imported into Hypermesh software for surface mesh division.

[0093] like Figures 7 and 8 As shown in the figure, after the surface mesh division is completed, the core shaft 1 and the external joint 4 are divided into three dimensions using Hypermesh software to obtain a three-dimensional mesh model of one quarter of the non-axisymmetric part F, which is then mapped using the reflect command on the XY plane and the YZ plane to obtain a complete three-dimensional mesh model; the nodes of these four quarters of the three-dimensional mesh model on the XY plane and the YZ plane are then processed as common nodes to obtain a three-dimensional mesh model of the non-axisymmetric part F.

[0094] like Figure 9 As shown, the obtained three-dimensional mesh model of the axisymmetric part Z and the three-dimensional mesh model of the non-axisymmetric part F are assembled; the outer surface of the outermost rubber layer and the inner circular surface of the outer joint are bound; the inner surface of the innermost rubber layer and the outer circular surface of the core shaft are bound to obtain the mesh model of the entire rod end joint, and the mesh division is completed.

[0095] This embodiment also includes a method for meshing a two-dimensional cross section with a dense outer surface and a sparse inner surface, such as Figures 10-14 As shown, specifically including:

[0096] Get the outermost basic control point on the two-dimensional section; Figure 11 As shown, the outermost basic control point in this embodiment is D3, which is the right end point of the inner side profile of the innermost rubber layer.

[0097] like Figure 11 As shown, the distance from the outermost base point D3 to the inner edge of the two-dimensional cross-section along the X-axis direction is obtained. In this embodiment, the inner edge of the two-dimensional cross-section is located on the Y-axis, and the distance obtained in this embodiment is the vertical distance, that is, the vertical distance d from D3 to the Y-axis.

[0098] like Figure 11 As shown, according to the distance ratio, similarly, the distance ratio in this embodiment is also the vertical distance ratio. In this embodiment, according to the ratio of e=0.8d and f=0.6d, two basic control points D4 and D5 located on the two-dimensional cross-section are respectively obtained, e is the distance from point D4 to the Y axis, and size f is the distance from point D5 to the Y axis.

[0099] like Figures 11-12 As shown, with two basic control points D4 and D5 as starting points, basic control lines L2 and L3 are drawn respectively, dividing the two-dimensional cross section into three regions: S1, S2, and S3. S1 is the region to the right of L2, S2 is the region between L2 and L3, and S3 is the region between L3 and the Y axis. S1 is the mesh refinement region, S2 is the transition region, and S3 is the mesh coarsening region.

[0100] In this embodiment, Figure 11 As shown, before drawing the basic control lines L2 and L3, the process also includes obtaining a first auxiliary point D1 located above the outer edge of the two-dimensional cross section and a second auxiliary point D2 located below the outer edge of the two-dimensional cross section, and connecting the first auxiliary point D1 and the second auxiliary point D2 to form the auxiliary line L1.

[0101] In this embodiment, Figure 11 As shown, the auxiliary line L1 forms a basic angle a with the Y axis, the angle formed by L2 with the Y axis is recorded as b, and the angle formed by L3 with the Y axis is recorded as c, and they satisfy the proportional relationship of b=0.75a and c=0.45a.

[0102] In this embodiment, Figures 12-14 As shown, in the process of dividing the three regions S1, S2, and S3, the grid cell sizes are proportional. Specifically, the grid cell size ratio between the transition region S2 and the grid refinement region S1 is 1.5, and the grid cell size ratio between the grid coarsening region S3 and the grid refinement region S1 is 2. In this embodiment, the grid cell size in region S1 is 0.3, the grid cell size in region S2 is 0.45, and the grid cell size in region S3 is 0.6.

[0103] In this embodiment, Figure 14 As shown in the figure, the ratio of the number of grid layers between the grid coarsening area S3 and the grid refinement area S1 is 0.5 and 0.7 respectively according to the different materials of the rubber and the spacer. Specifically, the number of grid layers at the leftmost end of the rubber in the grid refinement area S1 is 6, and the number of grids at the leftmost end of the rubber in the grid coarsening area S2 is reduced to 3. The number of grids at the leftmost end of the spacer in the grid refinement area S1 is 3, and the number of grids at the leftmost end of the spacer in the grid coarsening area S2 is reduced to 2.

[0104] This embodiment adopts a dense outer and sparse inner grid division method, and adopts a decreasing grid size for non-critical areas inside the multi-layer metal rubber part to control the overall grid size, thereby ensuring calculation accuracy and improving calculation efficiency.

[0105] This embodiment also includes a free-form surface meshing method, such as Figures 15 to 23 As shown, it includes: obtaining the two-dimensional cross-section C of the rod end joint and the enlarged view C' of the free surface.

[0106] like Figure 18 As shown, the free-form surface includes a sharp corner area A. In this embodiment, the sharp corner area A includes a first arc segment R01 and a second arc segment R02 intersecting each other, a first straight line segment L1 intersecting the second arc segment R02, a third arc segment R03 intersecting the other end of the first straight line segment L1, and a second straight line segment L2 intersecting the first arc segment R01.

[0107] like Figure 19 As shown, the sharp corner area A of the free surface is blunted, including dragging the intersection of the second arc segment R02 and the first arc segment R01 to the midpoint P1 of the first arc segment R01; and dragging the intersection of the second straight line segment L2 and the first arc segment R01 to the outer end point P2 of the first arc segment R01 on the free surface.

[0108] In this embodiment, the free-form surface is segmented based on the midpoint P1 of the first arc segment R01, the intersection P3 of the second arc segment R02 and the first straight line segment L1, and the midpoint P4 of the third arc segment R03 as basic control points;

[0109] A basic control line is extended from the basic control point toward the rod end joint body, thereby cutting the surface area located inside the free surface on the two-dimensional cross section into multiple closed and open sub-surface areas through the basic control line; in this embodiment, the direction of the rod end joint body is to the left.

[0110] The sub-face regions are respectively subjected to tetrahedral mesh layout to form a full-section mesh layout.

[0111] The specific division method in this embodiment is as follows:

[0112] 1. When extending the basic control line from the midpoint P1 of the first arc segment R01, the following steps are specifically included:

[0113] like Figures 20-21 As shown, obtain the midpoint P1 of the first arc segment R01 and the inner endpoint P5 of the free surface, and the midpoint P6 of the second arc segment R02, connect the midpoint P1 and endpoint P5 of the first arc segment R01 to form a first auxiliary line L1'; connect the midpoint P6 of the second arc segment R02 and the midpoint P1 of the first arc segment R01 to form a second auxiliary line L2'; the first auxiliary line L1' and the second auxiliary line L2' form an angle α, and take the midpoint P1 of the first arc segment R01 as the starting point, and draw a straight line with an angle of α / 2 as the first basic control line B1.

[0114] 2. If Figures 20-21 As shown, when the basic control line is extended from the midpoint P4 of the third arc segment R03, the following steps are specifically included:

[0115] Get the midpoint P4 of the third arc segment R03 and the intersection of the third arc segment R03 and the first straight line segment L1, connect the midpoint P4 of the third arc segment R03 and the intersection P7 of the third arc segment R03 and the first straight line segment L1 to form a third auxiliary line L3'; with the midpoint P4 of the third arc segment R03 as the starting point, make a fourth auxiliary line L4' perpendicular to the third arc segment R03; the third auxiliary line L3' and the fourth auxiliary line L4' form an angle β, with the midpoint P4 of the third arc segment R03 as the starting point, make a straight line with an angle of β / 3 as the second basic control line B2.

[0116] 3. If Figure 21 As shown, with the endpoint P8 of the second basic control line B2 as the starting point, a third basic control line B3 is made parallel to the first straight line segment L1 and intersects with the first basic control line B1 at P9.

[0117] 4. If Figure 21 As shown, with the intersection point P10 of the second arc segment R02 and the first straight line segment L1 as the starting point, a fourth basic control line B4 parallel to the second basic control line B2 is drawn, intersecting with the third basic control line B3.

[0118] 5. If Figures 21-23 As shown, starting from the intersection P9 of the first basic control line B1 and the third basic control line B3, the midpoint P6 of the second arc segment R02 is connected to form the fifth auxiliary line L5'; starting from the intersection P11 of the third basic control line B3 and the fourth basic control line B4, the midpoint of the fifth auxiliary line L5' is connected and extended to the first basic control line B1 to form the fifth basic control line B5.

[0119] like Figures 21-23 As shown, in this embodiment, basic control lines B1 to B5 cut the surface area located inside the free-form surface on the two-dimensional cross section into multiple closed sub-surface areas, and the auxiliary lines are deleted; thus, the meshing of the free-form surface is completed.

[0120] Obviously, the above embodiments are merely examples for the purpose of clearly illustrating the technical solutions of the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be protected by the claims of the present invention.

Claims

1. A multi-layer rod end joint meshing method, characterized in that: include: Dividing the multi-layer rod end joint into an axisymmetric part and an asymmetric part, wherein the axisymmetric part includes multiple layers of rubber and a spacer, and the asymmetric part includes a core shaft and an outer joint; Performing two-dimensional cross-section processing on the axisymmetric portion and meshing the two-dimensional cross-section; The two-dimensional cross-section mesh after meshing is rotated into a three-dimensional mesh, the meshing of the axisymmetric part is completed, and a three-dimensional mesh model of the axisymmetric part is obtained; Performing geometric model processing on the non-axisymmetric part, and meshing the non-axisymmetric part after the geometric model processing to obtain a three-dimensional mesh model of the non-axisymmetric part; Assembling and binding the axisymmetric three-dimensional mesh model and the non-axisymmetric three-dimensional mesh model to complete the multi-layer rod end joint mesh division; Meshing the two-dimensional cross section further includes processing a free surface between the rubber and the spacer, the free surface including a sharp corner region, the sharp corner region including at least a first arc segment and a second arc segment intersecting each other, a first straight line segment intersecting the second arc segment, and a third arc segment intersecting the other end of the first straight line segment; performing a passivation process on the sharp corner area of ​​the free-form surface, wherein the passivation process comprises dragging the intersection point of the second arc segment and the first arc segment to the midpoint of the first arc segment; The free-form surface is segmented based on the midpoint of the first arc segment, the intersection of the second arc segment and the first straight line segment, and the midpoint of the third arc segment as basic control points; Extending a basic control line from the basic control point toward the rod end joint body, thereby cutting the surface area located inside the free-form surface on the two-dimensional cross section into a plurality of closed or open sub-surface areas through the basic control line; The sub-face regions are respectively subjected to tetrahedral grid layout to form a full-section grid layout.

2. The multi-layer rod end joint meshing method according to claim 1, characterized in that: The two-dimensional cross-section processing includes extracting two-dimensional cross-sections of the multi-layer rubber and the spacer of the axisymmetric portion, where the extracted portion is half of the cross-section to the right of the center line.

3. The multi-layer rod end joint meshing method according to claim 1, characterized in that: The rotation is based on Hypermesh software and specifically includes the following steps: S1. Use the spin command to rotate the 2D cross-section mesh 360 degrees around the X-axis to obtain a 3D mesh model of half the axisymmetric part. S2. Use the reflect command to map the half of the three-dimensional mesh model to the YZ plane to obtain a complete three-dimensional mesh model; S3. Then, the two halves of the mapped three-dimensional mesh model are subjected to common node processing on the YZ plane to obtain a three-dimensional mesh model of the axisymmetric part.

4. The multi-layer rod end joint meshing method according to claim 1, characterized in that: The geometric model processing is based on Proe software, and the geometric model processing simplifies the core shaft and the external joint of the non-axisymmetric part into a quarter of the core shaft and the external joint.

5. The multi-layer rod end joint meshing method according to claim 1, characterized in that: The meshing of the non-axisymmetric part after the geometric model processing is performed based on Hypermesh software, including: T1. After simplifying the geometric model, export the quarter core shaft and external joint in STP format. Import this file into Hypermesh software for surface meshing and 3D meshing to create a 3D mesh model of the quarter core shaft and external joint. T2. The three-dimensional mesh model of the quarter mandrel and the outer joint is divided into four parts using the reflect command and mapped to the XY plane and YZ plane to obtain four quarter three-dimensional mesh models; T3. Perform common node processing on the four quarter three-dimensional mesh models on the XY plane and the YZ plane.

6. The multi-layer rod end joint meshing method according to claim 1, characterized in that: Meshing the two-dimensional cross section includes: dividing the two-dimensional cross section into multiple parts from the inside out, and meshing according to the principle of dense outer part and sparse inner part; specifically including the following steps: Obtaining the outermost basic control point on the two-dimensional cross section; Obtaining the distance from the outermost basic point to the inner edge of the two-dimensional cross section along the X-axis direction, and obtaining a plurality of basic control points located on the two-dimensional cross section according to the distance ratio; Taking the multiple basic control points as starting points, respectively draw basic control lines to divide the two-dimensional cross section into multiple areas; The multiple regions are divided into grids respectively.

7. The multi-layer rod end joint meshing method according to claim 6, characterized in that: The distance from the outermost basic control point to the inner edge of the two-dimensional cross-section along the X-axis direction is a vertical distance.

8. The multi-layer rod end joint meshing method according to claim 6, characterized in that: Also includes: Obtain a first auxiliary point located above the outer edge on the two-dimensional cross-section and a second auxiliary point located below the outer edge on the two-dimensional cross-section, connect the first auxiliary point and the second auxiliary point to form an auxiliary line, and the auxiliary line forms a basic angle with the Y-axis; use the multiple basic control points as starting points to make basic control lines respectively, and the angles formed between the basic control lines and the Y-axis are proportional to the basic angle.

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