Train brake shoe filled with three-period minimal curved surface cell elements and modeling method

Abstract

The invention discloses a train brake shoe filled with three-period minimal curved surface cells and a modeling method.The train brake shoe comprises a steel billet layer, a TPMS cell filling layer and a wearing layer which are connected in sequence, and the TPMS cell filling layer is obtained after three-period minimal curved surface cells are mirrored, arrayed, bent and combined. The train brake shoe-TPMS composite structure has the remarkable effects that the train brake shoe-TPMS composite structure with light weight and high heat dissipation performance is obtained, the heat dissipation performance of the brake shoe is improved, the shock resistance is enhanced, and the weight of parts is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of train brake shoes, and particularly relates to a train brake shoe modeling method filled with triply periodic minimal surface (TPMS) cells. BACKGROUND

[0002] The train brake shoe is a core component of a train braking system, and converts train kinetic energy into heat energy through friction to achieve deceleration or parking. The braking effect of the train brake shoe mainly depends on the dissipation capacity of the friction heat. However, the traditional train brake shoe is mostly made of metal material, and has problems such as large weight, insufficient wear resistance, low heat dissipation efficiency, and limited impact resistance, and the connecting piece of the metal material is prone to failure due to friction and impact. Therefore, in order to adapt to different braking requirements and improve the braking performance, the material of the train brake shoe has evolved from cast iron to synthetic material, but the existing train brake shoe still cannot have both light weight and high heat dissipation performance.

[0003] Triply Periodic Minimal Surface (TPMS) is a kind of continuous smooth surface arranged periodically in three orthogonal directions and having zero average curvature, and the geometric characteristics thereof are accurately controlled by an implicit function. The TPMS structure has advantages of high specific surface area, strong pore connectivity, and adjustable topology, and exhibits excellent specific strength, energy absorption efficiency, and multi-physical field coupling performance (such as sound insulation, heat dissipation, and biocompatibility). At present, the TPMS structure has significant advantages in light weight, mechanical performance optimization, and energy absorption due to its high porosity and smooth and fully connected topological characteristics, and has been used in sandwich panels and other structures to improve mechanical performance and reduce weight.

[0004] Therefore, if the TPMS porous structure modeled by the implicit function can accurately control the pore distribution and form mutually isolated double-continuous flow channels, it will have potential value for brake heat dissipation of the train brake shoe. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application aims to provide a train brake shoe filled with triply periodic minimal surface (TPMS) cells and a modeling method, so as to solve the problem that a train brake shoe-TPMS composite structure with both light weight and high heat dissipation performance cannot be efficiently generated in the modeling process.

[0006] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: In a first aspect, the present application provides a train brake shoe filled with triply periodic minimal surface (TPMS) cells, and the key lies in that the train brake shoe comprises a steel blank layer, a TPMS cell filling layer, and a wear layer connected in sequence, wherein the TPMS cell filling layer is obtained by mirroring, arraying, bending, and combining triply periodic minimal surface (TPMS) cells.

[0007] Further, the TPMS cell filling layer is obtained by the following process: An implicit function equation of the tri-periodic minimal surface is written, and an image model of a single tri-periodic minimal surface cell is generated; A reverse modeling software is used to perform reverse modeling on the tri-periodic minimal surface cell, and a single tri-periodic minimal surface cell model is obtained; After mirror image and array operations are performed on the generated tri-periodic minimal surface cell model by using a three-dimensional modeling software, a single cell model is obtained by using a surface offset command and a stitching command; The train brake shoe is divided into three parts, i.e., a steel blank layer, a filling layer and a wear layer, by using the three-dimensional modeling software, and after array, bending and combination operations are performed on the generated single cell model, a Boolean operation is performed on the filling layer, so that the TPMS cell filling layer is formed.

[0008] Further, the specific process of using the reverse modeling software to perform reverse modeling on the tri-periodic minimal surface cell and obtaining the single tri-periodic minimal surface cell model is as follows: The image model of the single tri-periodic minimal surface cell is imported; A normal correction command is executed to correct the coordinate axis direction and adjust the position of the image model; A surface cutting command is used to cut the surface, and an eighth surface is obtained; The brush tool is used to delete the redundant sheet part of the eighth surface; The boundary of the eighth surface is constructed, i.e., the contour boundary is generated; A spline curve is used to outline the 3D contour of the surface, and a traditional boundary fitting command is used to obtain the surface; The surface is extended; A sketch is drawn and a loft is laid out on the front, upper and right surfaces; The surface is trimmed, and the entity structure of the eighth surface is obtained; Mirror image and Boolean operation are performed, and reverse modeling is completed, so that the single tri-periodic minimal surface cell model is obtained.

[0009] In a second aspect, the application provides a modeling method of the tri-periodic minimal surface cell filled train brake shoe, which comprises the following steps: Step 1: An implicit function equation of the tri-periodic minimal surface is written, and an image model of a single tri-periodic minimal surface cell is generated; Step 2: A reverse modeling software is used to perform reverse modeling on the tri-periodic minimal surface cell, and a single tri-periodic minimal surface cell model is obtained; Step 3: After mirror image and array operations are performed on the tri-periodic minimal surface cell model generated in step 2 by using a three-dimensional modeling software, a single cell model is obtained by using a surface offset command and a stitching command; Step 4, using three-dimensional modeling software to divide the train brake shoe into three parts: the steel blank layer, the filling layer and the wear layer, and after array, bending and combination operations are performed on the single cell model generated in step 3, the Boolean operation is performed with the filling layer to form the TPMS cell filling layer; Step 5, based on the steel blank layer, the TPMS cell filling layer and the wear layer, the P-surface cell filling train brake shoe model is obtained.

[0010] Further, the implicit function equation of the three-period minimal surface is: Wherein, x, y, z are the coordinates of the three-period minimal surface midpoint.

[0011] Further, the specific process of reverse modeling of the three-period minimal surface cell in step 2 is as follows: Step 2.1, import the image model of a single three-period minimal surface cell; Step 2.2, execute the modified normal command to correct the coordinate axis direction to adjust the image model position; Step 2.3, use the surface cutting command to cut the surface to obtain an eighth surface; Step 2.4, use the brush tool to delete the excess piece part of the eighth surface; Step 2.5, construct the boundary of the eighth surface, that is, generate its contour boundary; Step 2.6, use spline curves to outline the 3D contour of the surface, and use the traditional boundary fitting command to obtain the surface; Step 2.7, extend the surface; Step 2.8, sketch and loft on the front, upper and right three faces; Step 2.9, trim the surface to obtain the solid structure of the eighth surface; Step 2.10, mirror and Boolean operation, complete the reverse modeling to obtain a single three-period minimal surface cell model.

[0012] Further, the specific process of the Boolean operation after the array and bending operations in step 4 to form the TPMS cell filling layer is as follows: Step 4.1, establish a three-dimensional model of the train brake shoe according to the casting brake shoe size standard, and divide it into three parts: the steel blank layer, the filling layer and the wear layer; Step 4.2, array, bend and combine the single cell model obtained in step 3 to obtain the P-surface cell filling layer; Step 4.3, perform Boolean operation on the filling layer and the P-surface cell filling layer to obtain the P-surface cell filling TPMS cell filling layer.

[0013] In a third aspect, the present application provides a modeling system of a train brake shoe filled with three-period minimal surface cells, for implementing the method according to any one of claims 4-7, and characterized by comprising: an image model generation unit configured to write an implicit function equation of the three-period minimal surface, and generate an image model of a single three-period minimal surface cell; a reverse modeling unit configured to perform reverse modeling on the three-period minimal surface cell to obtain a single three-period minimal surface cell model; a cell modeling unit configured to perform mirror and array operations on the generated three-period minimal surface cell model, and obtain a single cell model by using surface offset commands and stitching commands; a TPMS cell filling layer modeling unit configured to divide the three-dimensional model of the train brake shoe into three parts: a steel blank layer, a filling layer and a wear layer, and perform array, bending and combination operations on the single cell model, and then perform Boolean operation on the filling layer to form the TPMS cell filling layer; a train brake shoe model generation unit configured to obtain a P-surface cell filled train brake shoe model based on the steel blank layer, the TPMS cell filling layer and the wear layer.

[0014] In a fourth aspect, the present application provides a computer device, comprising a memory, a processor and a program stored in the memory and executable on the processor, wherein the processor implements the steps of the modeling method of a three-period minimal surface cell filled train brake shoe when executing the program.

[0015] In a fifth aspect, the present application provides a computer readable storage medium having a program stored thereon, wherein the program is executable on a processor to implement the steps of the modeling method of a three-period minimal surface cell filled train brake shoe.

[0016] The present application has the following remarkable effects: (1) Improved brake shoe heat dissipation performance: the three-period minimal surface has high specific surface area, connectivity and fluid dynamics characteristics, can induce spiral flow of fluid, destroy thermal boundary layer and enhance convective heat transfer, so that the structure exhibits significant advantages in heat dissipation performance; (2) Improved brake shoe impact resistance: the three-period minimal surface structure has high connectivity and smoothness of the curved surface and periodic topological design, and realizes energy absorption through layer-by-layer collapse, micro-crack accumulation and shear band formation during compression, thereby improving the impact resistance; (3) Reduced brake shoe part weight: the three-period minimal surface has high porosity and specific surface area, so that it has excellent mechanical properties while maintaining lightweight. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1This is a schematic diagram of the structure of the train brake shoe described in this invention; Figure 2 This is a front view of the train brake shoe described in this invention; Figure 3 This is a side view of the train brake shoe described in this invention; Figure 4 yes Figure 3 AA section view; Figure 5 This is a top view of the train brake shoe described in this invention; Figure 6 This is a flowchart of the modeling method described in this invention; Figure 7 This is a flowchart of the reverse modeling process described in this invention; Figure 8 This is a schematic diagram of the modeling process of the TPMS cell filling layer described in this invention; Figure 9 This is a schematic diagram of the process of obtaining the train brake shoes described in this invention; Figure 10 This is a principle block diagram of the modeling system described in this invention; Figure 11 This is a schematic block diagram of the computer device described in this invention. Detailed Implementation

[0018] The specific embodiments and working principles of the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] Example 1: like Figures 1-5 As shown, this embodiment provides a train brake shoe filled with three-period minimal curved surface cells, including a steel billet layer 1, a TPMS cell filling layer 2, and a wear layer 3 connected in sequence. The main function of the steel billet layer 1 is to connect with the braking device. The surface of the steel billet layer 1 away from the TPMS cell filling layer 2 is provided with components such as a brake shoe nose. The TPMS cell filling layer 2 is obtained by mirroring, arraying, bending, and combining three-period minimal curved surface cells, and its main function is heat dissipation and energy absorption. The wear layer 3 is in direct contact with the wheel tread and converts the kinetic energy of the train into heat energy through friction to complete the braking.

[0020] In this example, the process of obtaining the TPMS cell filling layer 2 is as follows: Using Matlab numerical analysis software, implicit function equations for a three-period minimum surface were written, an image model of a single three-period minimum surface cell was generated, and the STL format model of the three-period minimum surface cell model was exported using the stlwrite function. Using Geomagic reverse modeling software, reverse modeling of a three-period minimal surface cell was performed to obtain a single three-period minimal surface cell model, and the STP format model of the single cell model was exported. In the specific implementation process, the interface between the Matlab software and the Geomagic software is established through the interface file stlwrite.m; After mirroring and arraying the generated three-period minimal surface cell model using SolidWorks 3D modeling software, a single cell model is obtained by using the surface offset command and the stitching command. Using SolidWorks 3D modeling software, the train brake shoe is divided into three parts: steel blank layer, filling layer and wear layer 3. After arraying, bending and combining the generated individual cell model, Boolean operation is performed with the filling layer to form the TPMS cell filling layer 2.

[0021] Preferably, the specific process of using reverse modeling software to perform reverse modeling of the three-period minimal surface cell to obtain a single three-period minimal surface cell model is as follows: The STL format of the three-period minimal surface cell model was imported into the reverse modeling software Geomagic DesignX; Execute the Correct Normal command to correct the coordinate axis orientation and adjust the position of the image model; Use the surface cut command to cut the surface and obtain an eighth of the surface, which will facilitate subsequent trimming operations. Use the brush tool to delete the excess sheet portion of the one-eighth surface; Constructing the boundary of an eighth-degree surface, that is, generating its contour boundary; Use spline curves to outline the 3D contour of the surface, and use the traditional boundary fitting command to obtain the surface; Extend the curved surface; Sketch and loft the front, top, and right sides; Trim the surface to obtain a solid structure with one-eighth of the surface; The model is mirrored and Boolean operations are performed, and the resulting cell entity is output in STP format. This completes the reverse modeling of the three-period minimal surface cell in STL format, and a single three-period minimal surface cell model is obtained.

[0022] Example 2: like Figure 6 As shown in the figure, this embodiment provides a modeling method for train brake shoes filled with three-period minimal surface cells. The specific steps are as follows: Step 1, using Matlab numerical analysis software, write the implicit function equation of three periodic minimal surface, generate a single three periodic minimal surface cell image model, export the stl format model of three periodic minimal surface cell by stlwrite function; Step 2, using Geomagic reverse modeling software to reverse model three periodic minimal surface cell, obtain a single three periodic minimal surface cell model, export the stp format model of single three periodic minimal surface cell model; Referring to the drawings Figure 7 The specific process of reverse modeling of three periodic minimal surface cell in step 2 is as follows: Step 2.1, import the stl format model of three periodic minimal surface cell model into the reverse modeling software GeomagicDesignX; Step 2.2, execute the correct normal command to correct the coordinate axis direction to adjust the image model position; Step 2.3, cut the surface using the surface cutting command to obtain one-eighth surface, which is convenient for subsequent trimming operation; Step 2.4, delete the excess sheet part of one-eighth surface by using the brush tool; Step 2.5, construct the boundary of one-eighth surface, that is, generate its contour boundary; Step 2.6, use spline curve to outline the 3D contour of the surface, and use the traditional boundary fitting command to obtain the surface; Step 2.7, extend the surface; Step 2.8, draw sketches and lofting on the front, upper and right surfaces; Step 2.9, trim the surface to obtain the entity structure of one-eighth surface; Step 2.10, mirror and Boolean operation, and output the obtained cell entity in stp format, complete the reverse modeling of stl format three periodic minimal surface cell, and obtain a single three periodic minimal surface cell model.

[0023] Step 3, using SolidWorks three-dimensional modeling software, mirror and array the three periodic minimal surface cell model generated in step 2, and use the surface offset command and stitching command to obtain a single cell model; Step 4, using SolidWorks three-dimensional modeling software, divide the train brake shoe into three parts: steel blank layer, filling layer and wear layer 3, and after array, bending and combination operation of the single cell model generated in step 3, perform Boolean operation with the filling layer to form the TPMS cell filling layer 2; In specific implementation, the specific process of performing Boolean operation with the filling layer after array and bending operation in step 4 to form the TPMS cell filling layer 2 is as follows: Step 4.1, a three-dimensional model of the train shoe is established according to the standard of the casting shoe size, and is divided into three parts: the billet layer 1, the filling layer and the wear layer 3; Step 4.2, the single cell model obtained in step 3 is arrayed, bent and combined to obtain the P-surface cell filling layer, as shown in Figure 8 ; Step 4.3, the filling layer and the P-surface cell filling layer are subjected to Boolean operation to obtain the P-surface cell filling TPMS cell filling layer 2.

[0024] Step 5, based on the billet layer 1, the TPMS cell filling layer 2 and the wear layer 3, a P-surface cell filling train shoe model is obtained, as shown in Figure 9 .

[0025] In this embodiment, the implicit function equation of the three-period minimal surface is: Wherein, x, y, z are the coordinates of the point of the three-period minimal surface.

[0026] Embodiment 3: As shown in Figure 9 , this embodiment provides a three-period minimal surface cell filling train shoe modeling system, which comprises: An image model generation unit for writing an implicit function equation of a three-period minimal surface to generate an image model of a single three-period minimal surface cell; A reverse modeling unit for reverse modeling the three-period minimal surface cell to obtain a single three-period minimal surface cell model; A cell modeling unit for mirroring and arraying the generated three-period minimal surface cell model, and then using surface offset commands and stitching commands to obtain a single cell model; A TPMS cell filling layer 2 modeling unit for dividing the three-dimensional model of the train shoe into three parts: the billet layer, the filling layer and the wear layer 3, and then arraying, bending and combining the single cell model and performing Boolean operation with the filling layer to form the TPMS cell filling layer 2; A train shoe model generation unit for obtaining a P-surface cell filling train shoe model based on the billet layer 1, the TPMS cell filling layer 2 and the wear layer 3.

[0027] Embodiment 4: As shown in Figure 10 , this embodiment provides a computer device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor executes the program to implement the steps of the three-period minimal surface cell filling train shoe modeling method.

[0028] The embodiment also provides a computer readable storage medium, which stores a program, and the program is executed by a processor to implement the steps of the three-period minimal surface cell filled train shoe modeling method.

[0029] To sum up, the three-dimensional model of the train shoe is established according to the size standard of the cast shoe, the three-dimensional model of the train shoe is divided into three layers, i.e., a steel blank layer, a filling layer and a wear layer 3, wherein the main function of the steel blank layer is to connect with the brake device, the main function of the filling layer is heat dissipation and energy absorption, and the wear layer 3 is directly in contact with the tread of the wheel and converts the kinetic energy of the train into heat energy through friction to complete braking. Then, the single three-period minimal surface cell model is subjected to array, bending and combination operations to form a P-surface cell filling layer, then Boolean operation is performed on the filling layer to obtain a P-surface cell filled TPMS cell filling layer 2, and thus the P-surface cell filled train shoe is obtained based on the steel blank layer 1, the TPMS cell filling layer 2 and the wear layer 3, so that the train shoe-TPMS composite structure with light weight and high heat dissipation performance is obtained, the composite structure improves the heat dissipation performance of the shoe, enhances the impact resistance and reduces the weight of the parts.

[0030] The technical solutions provided by the present application are described in detail above. The principles and implementation modes of the present application are described by applying specific examples, and the above examples are only used to help understand the method and core idea of the present application. It should be pointed out that, for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A train brake shoe filled with three-period minimal curved surface cells, characterized in that, It includes a billet layer, a TPMS cell filling layer and a wear layer connected in sequence, wherein the TPMS cell filling layer is obtained by mirroring, arraying, bending and combining three-period minimal surface cells.

2. The train brake shoe filled with three-period minimal curved surface cells according to claim 1, characterized in that: The process of obtaining the TPMS cell-filled layer is as follows: Write the implicit function equations for the three-period minimal surface and generate an image model of a single three-period minimal surface cell. The three-period minimal surface cell was modeled using reverse modeling software to obtain a single three-period minimal surface cell model. After mirroring and arraying the generated three-period minimal surface cell model using 3D modeling software, a single cell model is obtained by using the surface offset command and the stitching command. Using 3D modeling software, the train brake shoe is divided into three parts: a steel blank layer, a filling layer, and a wear layer. After arraying, bending, and combining the generated individual cell models, Boolean operations are performed with the filling layer to form the TPMS cell filling layer.

3. The train brake shoe filled with three-period minimal curved surface cells according to claim 2, characterized in that: The specific process of using reverse modeling software to perform reverse modeling of a three-period minimal surface cell to obtain a single three-period minimal surface cell model is as follows: Import the image model of a single three-period minimal surface cell; Execute the Correct Normal command to correct the coordinate axis orientation and adjust the position of the image model; Use the surface cut command to cut the surface and obtain an eighth-degree surface; Use the brush tool to delete the excess sheet portion of the one-eighth surface; Constructing the boundary of an eighth-degree surface, that is, generating its contour boundary; Use spline curves to outline the 3D contour of the surface, and use the traditional boundary fitting command to obtain the surface; Extend the curved surface; Sketch and loft the front, top, and right sides; Trim the surface to obtain a solid structure with one-eighth of the surface; Mirroring and Boolean operations are used to complete the reverse modeling and obtain a single three-period minimal surface cell model.

4. A modeling method for train brake shoes filled with three-period minimal surface cells as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Write the implicit function equations for the three-period minimal surface and generate an image model of a single three-period minimal surface cell. Step 2: Use reverse modeling software to reverse model the three-period minimal surface cell to obtain a single three-period minimal surface cell model. Step 3: After mirroring and arraying the three-period minimal surface cell model generated in Step 2 using 3D modeling software, obtain a single cell model using the surface offset command and the stitching command. Step 4: Using 3D modeling software, the train brake shoe is divided into three parts: steel blank layer, filling layer and wear layer. After performing array, bending and combination operations on the single cell model generated in Step 3, Boolean operations are performed with the filling layer to form the TPMS cell filling layer. Step 5: Obtain the train brake shoe model with P-surface cell filling based on the billet layer, TPMS cell filling layer and wear layer.

5. The modeling method for train brake shoes filled with three-period minimal surface cells according to claim 2, characterized in that: The implicit functional equation of the three-period minimum surface is: Where x, y, and z are the coordinates of the midpoint of the three-period minimal surface.

6. The modeling method for train brake shoes filled with three-period minimal surface cells according to claim 4, characterized in that: The specific process of reverse modeling the three-period minimal surface cell in step 2 is as follows: Step 2.1: Import the image model of a single three-period minimal surface cell; Step 2.2: Execute the Correct Normal command to correct the coordinate axis direction and adjust the position of the image model; Step 2.3: Use the surface cutting command to cut the surface to obtain an eighth-order surface; Step 2.4: Use the brush tool to delete the excess sheet parts of the one-eighth surface; Step 2.5: Construct the boundary of the 1 / 8 surface, that is, generate its contour boundary; Step 2.6: Use spline curves to outline the 3D contour of the surface, and use the traditional boundary fitting command to obtain the surface; Step 2.7: Extend the surface; Step 2.8: Draw sketches and loft on the front, top, and right faces; Step 2.9: Trim the surface to obtain a solid structure of one-eighth of the surface; Step 2.10: Mirroring and Boolean operations are performed to complete the reverse modeling and obtain a single three-period minimal surface cell model.

7. The modeling method for train brake shoes filled with three-period minimal surface cells according to claim 4, characterized in that: The specific process of performing Boolean operations with the filling layer after the arraying and bending operations in step 4 to form the TPMS cell filling layer is as follows: Step 4.1: Establish a three-dimensional model of the train brake shoe according to the standard dimensions of the cast brake shoe, and divide it into three parts: the billet layer, the filling layer, and the wear layer; Step 4.2: Array, bend, and combine the single cell models obtained in Step 3 to obtain the P-surface cell filling layer; Step 4.3: Perform Boolean operations on the filling layer and the P-surface cell filling layer to obtain the TPMS cell filling layer with P-surface cell filling.

8. A modeling system for train brake shoes filled with three-period minimal surface cells, used to implement the method as described in any one of claims 4-7, characterized in that, include: The image model generation unit is used to write the implicit function equations of the three-period minimal surface and generate an image model of a single three-period minimal surface cell. The reverse modeling unit is used to perform reverse modeling on the three-period minimal surface cell to obtain a single three-period minimal surface cell model. Cell modeling unit is used to mirror and array the generated three-period minimal surface cell model, and then obtain a single cell model using the surface offset command and the stitching command. The TPMS cell filling layer modeling unit is used to divide the three-dimensional model of the train brake shoe into three parts: steel blank layer, filling layer and wear layer. After performing array, bending and combination operations on the individual cell model, Boolean operations are performed with the filling layer to form the TPMS cell filling layer. The train brake shoe model generation unit is used to obtain a train brake shoe model with P-surface cell filling based on the billet layer, TPMS cell filling layer and wear layer.

9. A computer device comprising a memory, a processor, and a program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps in the modeling method for train brake shoes filled with three-period minimal surface cells as described in any one of claims 4-7.

10. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps in the modeling method for train brake shoes filled with three-period minimal surface cells as described in any one of claims 4-7.

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