Finite element-based thin-wall part and manufacturing method thereof

Abstract

The invention discloses a thin-wall part based on finite elements and a manufacturing method of the thin-wall part. The manufacturing method comprises the steps that a three-dimensional model of a part to be formed is established; performing grid division on the three-dimensional model to obtain a three-dimensional grid model; the material type, material parameters and 3D printing process parameters of the to-be-formed part are determined; performing heat treatment simulation according to the three-dimensional grid model and the material type to obtain a heat treatment simulation result; obtaining a reversible deformation compensation model according to a heat treatment simulation result; compensating the reversible deformation compensation model according to the compensation scale factor to obtain a compensated model; repairing the compensated model according to the strain scale factor and the anisotropic strain coefficient to obtain a repaired model; and 3D printing is conducted according to the repaired model, the material type and the 3D printing process parameters. The thin-wall part is manufactured through 3D printing, deformation compensation can be conducted in the modeling process, deformation is reduced, and meanwhile it is guaranteed that the size of the thin-wall part obtained through 3D printing is not changed.

Description

Technical Field

[0001] The invention relates to the technical field of thin-walled component manufacturing, and in particular to a thin-walled component based on finite element and a manufacturing method thereof. Background Art

[0002] The wall thickness of thin-walled parts is relatively thin, and its proportion to the overall size of the parts is very small. Parts with a ratio less than 1:20 are usually defined as thin-walled parts. Thin-walled parts have the advantages of light weight, fast heat dissipation, material saving, and higher strength after optimization. They are widely used in various fields of industrial production.

[0003] At present, most of these are manufactured through traditional processing technology. However, in the traditional processing process, due to the low rigidity and thin wall thickness of thin-walled parts, they are easily affected by other factors such as scratches of the tool during cutting, the design shape of the fixture, and vibration during processing, which leads to deformation of the thin-walled structure and poor surface quality, thus affecting the processing quality and precision of the thin-walled structure. At the same time, for thin-walled parts with complex shapes and structures, it is difficult to achieve integrated forming through machining.

[0004] Selective laser melting (SLM) technology makes it possible to directly form thin-walled parts, which brings new possibilities and opportunities for the manufacturing and processing of thin-walled parts. However, in the SLM forming process, some structures often need to be supported to complete printing. The purpose is to play a supporting role on the one hand and to accelerate heat conduction to reduce re-deformation on the other hand. In fact, the support itself is a thin-walled structure, so the performance of the thin-walled structure is also crucial for the parts that need support. Moreover, since the SLM forming process undergoes a stage of rapid melting and rapid cooling, the temperature gradient is large, resulting in large thermal stress. Under the action of thermal stress, the parts are warped, cracked, and even print failure. Therefore, one of the main challenges of SLM technology is to reduce the deformation caused by the residual stress generated by the material during the forming process. At present, one of the most common SLM technical methods is to continuously optimize the process parameters through experiments to obtain the optimal process parameters and reduce the generation of residual stress. However, this method often consumes a lot of costs and the effect is unsatisfactory. Therefore, new technical means are urgently needed to solve the deformation problem caused by large residual stress in the process of SLM forming thin-walled parts, so as to achieve the ideal effect of reducing deformation. Summary of the invention

[0005] In order to solve the technical problems existing in the background technology, the present invention proposes a thin-walled part based on finite element and a manufacturing method thereof.

[0006] The present invention proposes a method for manufacturing a thin-walled part based on finite element, comprising:

[0007] Establish a three-dimensional model of the part to be molded;

[0008] Meshing the three-dimensional model to obtain a three-dimensional mesh model;

[0009] Determine the material type and material parameters of the part to be molded and the 3D printing process parameters; wherein the material parameters include strain proportional factor, anisotropic strain coefficient and compensation proportional factor;

[0010] Perform heat treatment simulation according to the three-dimensional mesh model and material type to obtain heat treatment simulation results;

[0011] According to the heat treatment simulation results, the repaired model is obtained;

[0012] Perform 3D printing based on the repaired model, material type, and 3D printing process parameters.

[0013] Preferably, according to the heat treatment simulation results, a repaired model is obtained, which specifically includes:

[0014] According to the heat treatment simulation results, the anti-deformation compensation model is obtained;

[0015] The anti-deformation compensation model is compensated according to the compensation scale factor to obtain a compensated model;

[0016] The compensated model is repaired according to the strain proportional factor and the anisotropic strain coefficient to obtain a repaired model.

[0017] Preferably, according to the heat treatment simulation results, an anti-deformation compensation model is obtained, which specifically includes:

[0018] The heat treatment simulation results are expressed as vector fields and a warpage model is generated;

[0019] The warping model is converted into an anti-deformation compensation model in the form of transformation vectors.

[0020] Preferably, in the process of meshing the three-dimensional model, at least two meshes cover the thinnest part of the three-dimensional mesh model.

[0021] Preferably, the 3D printing process parameters include laser power, scanning speed, layer thickness, laser spot diameter, phase initial angle, interlayer phase rotation angle, scanning spacing and band width.

[0022] Preferably, determining the strain proportional factor, the anisotropic strain coefficient and the compensation proportional factor in the material parameters specifically includes:

[0023] Establish a three-dimensional mesh model of the simulation part;

[0024] Perform heat treatment simulation according to the three-dimensional mesh model of the simulated part, initial material parameters and material type to obtain a simulated molded part;

[0025] According to the simulated molded part, the stress field distribution and deformation field distribution of the simulated molded part are obtained;

[0026] Printing is performed according to the three-dimensional mesh model of the simulated part, molding materials, and 3D printing process parameters to obtain an intermediate 3D molded part;

[0027] Measure and calculate the intermediate 3D molded part to obtain the stress field distribution and deformation field distribution of the intermediate molded part;

[0028] Compare the stress field distribution and deformation field distribution of the simulated molded part with the stress field distribution and deformation field distribution of the intermediate molded part;

[0029] If the stress field distribution and deformation field distribution of the simulated molded part do not match the stress field distribution and deformation field distribution of the intermediate molded part, the strain proportional factor and the anisotropic strain coefficient are iterated and re-compared until the stress field distribution and deformation field distribution of the simulated molded part match the stress field distribution and deformation field distribution of the intermediate molded part;

[0030] The strain proportional factor and anisotropic strain coefficient during matching are used as the strain proportional factor and anisotropic strain coefficient in the material parameters;

[0031] The compensation scaling factor is determined according to the number of iterations.

[0032] Preferably, the material type is selected as AlSi10Mg.

[0033] Preferably, the strain proportional factor is selected as 1.234, the anisotropic strain coefficient is selected as 1.338, 0.662 and 1.000, and the compensation proportional factor is selected as 0.5.

[0034] Preferably, the laser power is 180 W, the scanning speed is 850 mm / s, the laser spot diameter is 60 μm, the layer thickness is 3.0 μm, the initial phase angle is 0, the interlayer phase rotation angle is 67°, the scanning spacing is 0.08 mm, and the belt width is 10 mm.

[0035] The present invention further proposes a finite element-based thin-walled part, which is manufactured by using any of the above-mentioned finite element-based thin-walled part manufacturing methods.

[0036] In the present invention, the proposed finite element-based thin-walled parts and their manufacturing method manufacture thin-walled parts through 3D printing, which can compensate for deformation during the modeling process, while reducing deformation and ensuring that the size of the 3D printed thin-walled parts remains unchanged. Therefore, subsequent processing does not require changes to existing equipment, effectively reducing costs and workload, being easy to implement, and having strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic flow chart of a method for manufacturing thin-walled parts based on finite elements in one embodiment of the present invention.

[0038] Figure 2 It is a schematic structural diagram of a three-dimensional model in an embodiment of the present invention.

[0039] Figure 3 It is a schematic structural diagram of a compensated model in an embodiment of the present invention.

[0040] Figure 4 A schematic structural diagram of a 3D-printed thin-walled part in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] Reference Figure 1-4 The present invention proposes a method for manufacturing a thin-walled part based on finite element, comprising:

[0043] Establish a three-dimensional model of the part to be molded;

[0044] Meshing the three-dimensional model to obtain a three-dimensional mesh model;

[0045] Determine the material type and material parameters of the part to be molded and the 3D printing process parameters; wherein the material parameters include strain scale factor (SSF), anisotropic strain coefficients (ASCs) and compensation scale factor;

[0046] Perform heat treatment simulation according to the three-dimensional mesh model and material type to obtain heat treatment simulation results;

[0047] According to the heat treatment simulation results, the repaired model is obtained;

[0048] Perform 3D printing based on the repaired model, material type, and 3D printing process parameters.

[0049] The present invention manufactures thin-walled parts through 3D printing, and can compensate for deformation during the modeling process, thereby reducing deformation while ensuring that the size of the thin-walled parts printed by 3D printing remains unchanged. Therefore, subsequent processing does not require changes to existing equipment, effectively reducing costs and workload, being easy to implement, and having strong practicality.

[0050] In this embodiment, according to the heat treatment simulation results, a repaired model is obtained, which specifically includes:

[0051] According to the heat treatment simulation results, the anti-deformation compensation model is obtained;

[0052] The anti-deformation compensation model is compensated according to the compensation scale factor to obtain a compensated model;

[0053] The compensated model is repaired according to the strain proportional factor and the anisotropic strain coefficient to obtain a repaired model.

[0054] Among them, according to the heat treatment simulation results, the anti-deformation compensation mold is obtained, which specifically includes:

[0055] The heat treatment simulation results are expressed as vector fields and a warpage model is generated;

[0056] The warping model is converted into an anti-deformation compensation model in the form of transformation vectors.

[0057] In the process of meshing the three-dimensional model, at least two meshes cover the thinnest part of the three-dimensional mesh model to facilitate subsequent deformation compensation.

[0058] It should be noted that the 3D modeling software in this embodiment is Solidworks software, UG software or PRO-E software, and the format is .stl format.

[0059] The simulation software in this embodiment is ANSYS Additive simulation software, and the repair software is VoxeldanceAdditive, which is used to repair the compensated model according to the strain scale factor (SSF) and the anisotropic strain coefficient (ASCs) to obtain the repaired model.

[0060] In this embodiment, the 3D printing process parameters include laser power, scanning speed, layer thickness, laser spot diameter, phase initial angle, interlayer phase rotation angle, scanning spacing and band width.

[0061] In order to compensate for deformation during the modeling process and ensure that the size of the 3D printed thin-walled part remains unchanged while reducing deformation, in this embodiment, the strain scale factor (SSF) and anisotropic strain coefficient (ASCs) and compensation scale factor in the material parameters are determined, specifically including:

[0062] Establish a three-dimensional mesh model of the simulation part;

[0063] Perform heat treatment simulation according to the three-dimensional mesh model of the simulated part, initial material parameters and material type to obtain a simulated molded part;

[0064] According to the simulated molded part, the stress field distribution and deformation field distribution of the simulated molded part are obtained;

[0065] Printing is performed according to the three-dimensional mesh model, molding material, and 3D printing process parameters of the simulated part to obtain an intermediate 3D molded part;

[0066] Measure and calculate the intermediate 3D molded part to obtain the stress field distribution and deformation field distribution of the intermediate molded part;

[0067] Compare the stress field distribution and deformation field distribution of the simulated molded part with the stress field distribution and deformation field distribution of the intermediate molded part;

[0068] If the stress field distribution and deformation field distribution of the simulated molded part do not match the stress field distribution and deformation field distribution of the intermediate molded part, the strain scale factor (SSF) and the anisotropic strain coefficient (ASCs) are iterated and re-compared until the stress field distribution and deformation field distribution of the simulated molded part match the stress field distribution and deformation field distribution of the intermediate molded part;

[0069] The strain proportionality factor (SSF) and anisotropic strain coefficients (ASCs) during matching are used as the strain proportionality factor (SSF) and anisotropic strain coefficients (ASCs) in the material parameters;

[0070] The compensation scaling factor is determined according to the number of iterations.

[0071] In one specific embodiment, determining the compensation scale factor according to the number of iterations specifically includes:

[0072] When the number of iterations is one, the compensation scale factor is 0.75.

[0073] In another specific embodiment, determining the compensation scale factor according to the number of iterations specifically includes:

[0074] When the number of iterations is two, the compensation scale factor is 0.5.

[0075] It should be noted that when the compensation scale factor is 0.5, the deformation of the simulated molded part is small and the result is more ideal.

[0076] Specifically, the intermediate 3D molded parts are measured using tools such as laser scanners and 3D measuring instruments.

[0077] In the specific implementation, in order to select a thin-walled part with a relatively simple structure as a simulation part for modeling, simulation and actual printing, the material type and 3D printing process parameters are consistent with the material type and 3D printing process parameters of the part to be molded; then, after dividing the grid, start the analysis and calculation, import the calculated results into the ParaView software, select the position with larger deformation as the measurement point, and extract the deformation value of the position; at the same time, the printed intermediate 3D molded part is first scanned with 3D scanning software, and imported into the Polywork software to extract the deformation value of the same position; use these two deformation values ​​to calculate the strain proportional factor and anisotropic strain coefficient; after determining the strain proportional factor and anisotropic strain coefficient, the compensation proportional factor is determined according to the number of iterations. If it is iterated twice, it is generally selected as 0.5, and if it is iterated once, it is generally selected as 0.75.

[0078] The present invention further proposes a finite element-based thin-walled part, which is manufactured by using any of the above-mentioned finite element-based thin-walled part manufacturing methods.

[0079] In this embodiment, the thin-walled part manufactured by the manufacturing method of the thin-walled part based on finite element as described in any one of the above items has high quality and precision.

[0080] The present invention will be described below with reference to specific embodiments.

[0081] Example 1

[0082] This embodiment provides a method for manufacturing a thin-walled part based on finite element method, comprising:

[0083] S1. Use 3D modeling software to build a 3D model of the part to be molded, and import the 3D model into ANSYS Additive simulation software;

[0084] S2, select the simulation type and divide the grid;

[0085] S3, selecting the material type and material parameters of the part to be molded, and determining the 3D printing process parameters;

[0086] S4. Perform heat treatment simulation according to the three-dimensional mesh model and material type to obtain heat treatment simulation results;

[0087] S5. Obtaining an anti-deformation compensation model according to the heat treatment simulation results;

[0088] S6, compensating the anti-deformation compensation model according to the compensation scale factor to obtain a compensated model;

[0089] S7, repairing the compensated model according to the strain scale factor (SSF) and the anisotropic strain coefficients (ASCs) in VoxeldanceAdditive to repair the damaged triangular facets and obtain a repaired model;

[0090] S8. Perform 3D printing according to the repaired model, material type and 3D printing process parameters.

[0091] Specifically, the three-dimensional modeling software used in step S1 may be Solidworks software, UG software or PRO-E software. Figure 2 This is a thin-walled part created in UG software with a diameter of 100 mm, a height of 100 mm, and a wall thickness of 1 mm. Figure 3 is the compensated model. The printed parts are as follows Figure 4 shown.

[0092] Select the thermal stress analysis module in S2, edit the basic information of the part to be molded, and then divide the mesh. Select a mesh size of 0.5mm. When dividing the mesh, at least two meshes must cover the thinnest part of the finite element model. The wall thickness of this model is relatively thin, 1mm, so the mesh size is 0.5mm.

[0093] Among them, the material type is selected as AlSi10Mg, and the material parameters include strain scale factor (SSF), anisotropic strain coefficient (ASCs) and compensation scale factor. The strain scale factor (SSF) is selected as 1.234, the anisotropic strain coefficient (ASCs) is selected as (1.338, 0.662, 1.000), and the compensation scale factor is selected as 0.5.

[0094] Among them, the 3D printing process parameters are: substrate preheating temperature is 100°C, laser power is 180W, scanning speed is 850mm / s, laser spot diameter is 60μm, layer thickness is 3.0μm, phase initial angle is 0, interlayer phase rotation angle is 67°, scanning spacing is 0.08mm, and belt width is 10mm.

[0095] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for manufacturing thin-walled parts based on finite element, characterized in that: include: Establish a three-dimensional model of the part to be molded; Meshing the three-dimensional model to obtain a three-dimensional mesh model; Determine the material type, material parameters and 3D printing process parameters of the part to be molded; wherein the material parameters include strain proportional factor, anisotropic strain coefficient and compensation proportional factor; Perform heat treatment simulation according to the three-dimensional mesh model and material type to obtain heat treatment simulation results; According to the heat treatment simulation results, the repaired model is obtained; Perform 3D printing based on the repaired model, material type, and 3D printing process parameters.

2. The method for manufacturing thin-walled parts based on finite element analysis according to claim 1, characterized in that: According to the heat treatment simulation results, the repaired model is obtained, including: According to the heat treatment simulation results, the anti-deformation compensation model is obtained; The anti-deformation compensation model is compensated according to the compensation scale factor to obtain a compensated model; The compensated model is repaired according to the strain proportional factor and the anisotropic strain coefficient to obtain a repaired model.

3. The method for manufacturing thin-walled parts based on finite element analysis according to claim 2, characterized in that: According to the heat treatment simulation results, the anti-deformation compensation model is obtained, which specifically includes: The heat treatment simulation results are expressed as vector fields and a warpage model is generated; The warping model is converted into an anti-deformation compensation model in the form of transformation vectors.

4. The method for manufacturing thin-walled parts based on finite element analysis according to claim 1, characterized in that: In the process of meshing a three-dimensional model, at least two meshes cover the thinnest part of the three-dimensional mesh model.

5. The method for manufacturing thin-walled parts based on finite element analysis according to claim 1, characterized in that: The 3D printing process parameters include laser power, scanning speed, layer thickness, laser spot diameter, phase initial angle, interlayer phase rotation angle, scanning spacing and belt width.

6. The method for manufacturing thin-walled parts based on finite element analysis according to claim 5, characterized in that: The laser power is 180 W, the scanning speed is 850 mm / s, the laser spot diameter is 60 μm, the layer thickness is 3.0 μm, the initial phase angle is 0, the interlayer phase rotation angle is 67°, the scanning spacing is 0.08 mm, and the belt width is 10 mm.

7. The method for manufacturing thin-walled parts based on finite element analysis according to claim 1, characterized in that: Determine the strain proportional factor, anisotropic strain coefficient and compensation proportional factor in the material parameters, including: Establish a three-dimensional mesh model of the simulation part; Perform heat treatment simulation according to the three-dimensional mesh model of the simulated part, initial material parameters and material type to obtain a simulated molded part; According to the simulated molded part, the stress field distribution and deformation field distribution of the simulated molded part are obtained; Printing is performed according to the three-dimensional mesh model of the simulated part, molding materials, and 3D printing process parameters to obtain an intermediate 3D molded part; Measure and calculate the intermediate 3D molded part to obtain the stress field distribution and deformation field distribution of the intermediate molded part; Compare the stress field distribution and deformation field distribution of the simulated molded part with the stress field distribution and deformation field distribution of the intermediate molded part; If the stress field distribution and deformation field distribution of the simulated molded part do not match the stress field distribution and deformation field distribution of the intermediate molded part, the strain proportional factor and the anisotropic strain coefficient are iterated and re-compared until the stress field distribution and deformation field distribution of the simulated molded part match the stress field distribution and deformation field distribution of the intermediate molded part; The strain proportional factor and anisotropic strain coefficient during matching are used as the strain proportional factor and anisotropic strain coefficient in the material parameters; The compensation scaling factor is determined according to the number of iterations.

8. The method for manufacturing thin-walled parts based on finite element analysis according to claim 1, characterized in that: The material type is selected as AlSi10Mg.

9. The method for manufacturing thin-walled parts based on finite element analysis according to claim 1, characterized in that: The strain proportional factor was selected as 1.234, the anisotropic strain coefficients were selected as 1.338, 0.662 and 1.000, and the compensation proportional factor was selected as 0.

5.

10. A thin-walled part based on finite element, characterized in that: The thin-walled part is manufactured by using the finite element-based thin-walled part manufacturing method as described in any one of claims 1 to 9.

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