A dual-phase lattice mixed crystal structure and an interface transition optimization design method thereof

Abstract

The application discloses a dual-phase lattice mixed crystal structure and a connecting interface transition optimization design method thereof, and relates to the technical field of 3D printing, and specifically discloses the following steps: selecting two different types of lattice structures, determining a mixed lattice structure arrangement mode; lattice structure node data generation; initializing a rod diameter parameter and creating an initial model, calculating volume data of the initial model; judging whether an absolute difference value of a calculated volume of the model and a target volume meets a requirement; for the model that does not meet the requirement, iteratively optimizing and adjusting a rod diameter parameter of a unit cell; and saving an optimal rod diameter parameter and establishing a three-dimensional model. According to the design method, the rod diameter between different unit cells is subjected to variable-diameter transition design, so that local stress concentration is effectively avoided under the premise of ensuring that the overall quality is unchanged, the balance between light weight and high performance is achieved, the compression mechanical performance of the lattice structure is significantly improved, and technical support can be provided for printing of a 3D printing structural part that needs to bear compression load.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, specifically to a two-phase lattice hybrid crystal structure and its interface transition optimization design method. Background Technology

[0002] 3D-printed lattice structures are lightweight, high-strength spatial networks composed of nodes and connecting rods, achieving material performance optimization through the periodic arrangement of units. Breaking through the limitations of traditional manufacturing, they can precisely mold complex internal geometries, significantly reducing weight and improving energy absorption, heat dissipation, and biocompatibility. The main types include planar lattices, truss lattices, and high-performance TPMS lattices, widely used in lightweight aerospace components, medical bone implants, and athletic shoe sole cushioning design. They are a core technology for additive manufacturing to empower high-end equipment and functional materials.

[0003] Existing 3D printed lattice structures mainly include two categories: single lattice structures and mixed lattice structures with the same rod diameter.

[0004] 1. The core design logic of a single-lattice structure is "single-cell forming priority." For example, only one type of cell, FCC or BCC, is selected as the structural unit. The overall lattice structure is usually designed as a regular cube composed of n×n×n cells, with uniform size for each cell. However, a single-lattice structure cannot meet the comprehensive load-bearing requirements under compression conditions: for example, pure FCC lattices have strong toughness but insufficient compressive strength; pure BCC lattices have excellent compressive strength but limited toughness, making it difficult to fully utilize the material's performance advantages.

[0005] 2. Mixed-phase lattice structures with the same rod diameter directly adopt the rod diameter parameters of a single-phase lattice, but fail to consider the inconsistency in rod diameters between different phases, leading to localized stress concentrations at the junctions of different unit cells. Therefore, such two-phase mixed-phase lattice structures are prone to cracking and localized failure under compression conditions, severely impacting their service life. To avoid rod diameter differences, existing technologies typically unify dimensions by sacrificing the performance of the mixed crystal structure (reducing the rod diameter) or increasing the overall mass (increasing the rod diameter). This can easily lead to weakened localized mechanical properties, contradicting the initial goal of lightweight design.

[0006] Therefore, the industry urgently needs a design method for optimizing the transition of the interface of a two-phase lattice hybrid crystal structure, which can improve the compressive mechanical properties of the crystal structure while ensuring that the overall quality remains unchanged, and provide more reliable technical support for 3D printed structural parts that need to withstand compressive loads. Summary of the Invention

[0007] This invention provides a method for optimizing the transition of the connection interface in a two-phase lattice hybrid crystal structure to overcome the problems mentioned in the background art.

[0008] To achieve the above objectives, this invention provides a method for optimizing the transition of the interface in a two-phase lattice hybrid crystal structure, comprising the following steps:

[0009] S1. Select two different types of lattice structures according to the design requirements, and determine the arrangement of the mixed lattice structure;

[0010] S2. In Python software, first define the size of a single unit cell in the lattice structure and the size of the hybrid lattice structure, and define the hybrid lattice structure as an n×n×n lattice structure. Set the unit cell sharing type of each lattice node according to the arrangement of the hybrid lattice structure. Then, establish a regular grid structure consistent with the hybrid lattice structure. Next, alternately arrange the two types of unit cells in the regular grid structure, and identify the properties of each node according to the type of the unit cells surrounding the node. Finally, export and save all node information. document;

[0011] S3. Calculate the transition rod diameter based on the custom initial rod diameter parameters, and create a SpaceClaim executable modeling script based on the node information, initial rod diameter parameters and transition rod diameter obtained in step S2. Run the executable modeling script to create the initial model of the hybrid lattice structure and calculate the volume data of the initial model.

[0012] S4. Determine whether the absolute difference between the calculated volume of the initial model and the target volume of the hybrid lattice structure meets the design requirements. If it does, then prove that the initial rod diameter parameter is the optimal rod diameter parameter and proceed to step S6; if it does not, proceed to step S5.

[0013] S5. Adjust the rod diameter parameters for the two types of unit cells respectively, and then recreate the SpaceClaim executable modeling script using the node information and the adjusted rod diameter parameters. Next, call the newly created executable modeling script to generate the model under the new rod diameter parameters and recalculate the model volume. Compare the updated model volume with the target volume to determine whether the absolute difference between the two meets the design requirements. If it does, proceed to step S6. If it does not, repeat this step until the absolute difference between the model volume and the target volume meets the design requirements or the model volume no longer changes. Then, take the adjusted rod diameter parameters as the optimal rod diameter parameters and complete the iteration loop.

[0014] S6. Save the optimal rod diameter parameters, automatically generate and save the hybrid lattice structure model based on the executable modeling script.

[0015] Furthermore, in step S3, the transition rod diameters for the two types of unit cell connections are calculated using the average value method:

[0016]

[0017] in, For custom input of the initial rod diameter, The initial rod diameter is set to the user-defined input. This refers to the diameter of the transition rod.

[0018] Furthermore, in step S4, the design requirement to be met is that the absolute difference between the calculated model volume and the target volume of the hybrid lattice structure is within 200 mm³.

[0019] Furthermore, in step S5, the iterative adjustment of the rod diameter parameters of the two types of unit cells specifically involves: if the calculated volume of the updated model is smaller than the target volume, then the rod diameter of both types of unit cells is increased simultaneously; if the calculated volume of the updated model is larger than the target volume, then the rod diameter of both types of unit cells is decreased simultaneously.

[0020] Furthermore, the calibration method for the cell transition connection in step S5 is as follows: First, establish a lattice node coordinate and type label file to complete the unified calibration of node spatial position, cell region, and node attributes; then read the calibration data and identify the transition connection between the two types of cells by node type; wherein, the starting end of the transition segment is connected to the large-diameter cell and the ending end of the transition segment is connected to the small-diameter cell.

[0021] Furthermore, in step S1, the lattice structure includes, but is not limited to, simple cubic, diamond structure, face-centered cubic lattice, and body-centered cubic lattice; the arrangement of the mixed lattice structure includes, but is not limited to, H-type, I-type, □-type, X-type, and Y-type.

[0022] The present invention also provides a two-phase lattice hybrid crystal structure, which is designed by the above-described optimization design method.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention discloses a method for optimizing the transition of the connection interface in a two-phase lattice hybrid crystal structure. By designing a variable rod diameter transition between different unit cells, it effectively avoids local stress concentration while ensuring that the overall mass remains unchanged. This achieves a balance between lightweight and high performance, significantly improving the compressive mechanical properties of the crystal structure. It can be widely used in the field of 3D printed structural parts that need to withstand compressive loads, such as lightweight load-bearing components, buffer protection structures, and industrial equipment support components.

[0025] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 This is a flowchart of a method for optimizing the transition of a connection interface in a two-phase lattice hybrid crystal structure according to an embodiment of the present invention;

[0028] Figure 2 This is a structural diagram of the mixed lattice structure in this invention; wherein, (a) is an X-type arrangement and (b) is a Y-type arrangement;

[0029] Figure 3 This is a schematic diagram of the hybrid lattice structure and nodes in this invention;

[0030] Figure 4 This is a three-stage transition design diagram for variable rod diameter according to an embodiment of the present invention; wherein, (a) is the transition connection design for unit cells with different rod diameters, (b) is the X-arrangement of the transition design, and (c) is the Y-arrangement of the transition design;

[0031] Figure 5 This is a comparison curve of compressive stress and strain between a hybrid lattice with transition optimization design and a hybrid lattice without transition optimization design in an embodiment of the present invention;

[0032] Figure 6 The above is a printed solid model of the crystal structure in an embodiment of the present invention; wherein, (a) is an X arrangement and (b) is a Y arrangement;

[0033] Figure 7 This is a compression test diagram of the universal testing machine used in the embodiments of the present invention;

[0034] Figure 8 The diagram shows a partial compression process experiment according to an embodiment of the present invention; wherein, (a) is a transitionless X arrangement, and (b) is a transitionless Y arrangement. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent transformations or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0036] like Figure 1 As shown, this embodiment provides a method for optimizing the transition of the interface in a two-phase lattice hybrid crystal structure, including the following steps:

[0037] S1. Select two different types of lattice structures according to the design requirements, and determine the arrangement of the mixed lattice structure. Specifically: the lattice structures include, but are not limited to, simple cubic, diamond structure, face-centered cubic lattice, and body-centered cubic lattice; the arrangement of the mixed lattice structure includes, but is not limited to, H-type, I-type, □-type, X-type, and Y-type.

[0038] S2. Lattice Structure Node Data Generation: In Python software, the dimensions of individual unit cells and the dimensions of the mixed lattice structure are first defined. The mixed lattice structure is an n×n×n lattice, and the unit cell sharing type of each lattice structure node is set according to the arrangement of the mixed lattice structure. Next, a regular grid structure consistent with the mixed lattice structure is created using Python code. Then, the two unit cell types are alternately arranged in this regular grid structure, and the properties of each node are identified according to the surrounding unit cell types. Finally, all node information is exported and saved as a .csv file. In this step, the unit cell sharing type includes nodes shared only by units of the same type and nodes shared by two different types of units.

[0039] S3. Initialization Parameters and Initial Model Creation: Different types of lattice structures, under the condition of the same volume and relative density, have different numbers of supporting rods per unit cell, thus the radii of the supporting rods must be different. Direct connection will lead to stress concentration. This invention employs a multi-level smooth transition method for cases where the rod diameters of different phase units are inconsistent: by inserting intermediate rod diameter segments to form a gradient transition of the stress-bearing cross-section, the connection point of the two different rod diameter units changes from an abrupt change in cross-section to a gradual and continuous change, ultimately achieving uniform stress transfer at the connection point. This fundamentally avoids the stress concentration problem caused by abrupt cross-section changes, improving the overall compressive strength, buckling resistance, and fracture resistance of the lattice structure. Specifically, between the originally directly connected large and small diameter rods, one (three-level transition) or multiple (four-level or higher transition) intermediate diameter rods are added. All rods are connected sequentially according to their diameter from large to small, forming a smooth rod diameter gradient. Furthermore, the transition segment and the rods of the units on both sides are integrally formed, ensuring the structural continuity of the connection and allowing the load to be gradually transferred along the rod diameter gradient, rather than concentrating the force at a single splicing point.

[0040] The transition bar diameters of two different types of unit cells are calculated based on the custom initial bar diameter parameters. Based on the node information obtained in step S2, the custom initial bar diameter parameters, and the calculated transition bar diameters, a SpaceClaim executable modeling script is created. The executable modeling script is run to create an initial model of the hybrid lattice structure and calculate the volume data of the initial model.

[0041] S4. Compare the calculated volume of the initial model with the target volume of the two-phase lattice hybrid lattice. If the absolute difference between the calculated volume of the initial model and the target volume of the two-phase lattice hybrid lattice meets the design requirements, then the initial rod diameter parameter is proven to be the optimal rod diameter parameter, and step S6 is executed; if the absolute difference between the calculated volume of the initial model and the target volume of the two-phase lattice hybrid lattice does not meet the design requirements, then step S5 is executed; wherein, the target volume of the two-phase lattice hybrid lattice is calculated based on the overall volume and density of the hybrid lattice.

[0042] S5. Iterative Optimization: If the model built under the current rod diameter does not meet the volume constraints, the rod diameter parameters for both types of unit cells are adjusted respectively. Then, the SpaceClaim executable modeling script is recreated using the node information and the adjusted rod diameter parameters. Next, the newly created executable modeling script is called to generate the model under the new rod diameter parameters, and the model volume is recalculated. The calculated volume of the updated model is compared with the target volume of the two-phase lattice hybrid lattice to determine whether the absolute difference between the two meets the design requirements. If it does, step S6 is executed; if not, this step is repeated iteratively until the absolute difference between the model volume and the target volume meets the design requirements or the model volume no longer changes. At this point, the adjusted rod diameter parameters are taken as the optimal rod diameter parameters, and the iterative cycle is completed. During this iterative optimization process, while ensuring that the overall mass remains unchanged, the specific dimensions of the rod diameter of each transition segment and the length ratio of each transition segment are iteratively adjusted to ensure constant mass and optimal mechanical properties.

[0043] S6. Save the optimal rod diameter parameters, automatically generate a hybrid lattice structure model based on the SpaceClaim script, and save it as a .stl file for subsequent model printing.

[0044] Example 1:

[0045] In this embodiment, two different types of lattice structures, FCC (face-centered cubic) and BCC (body-centered cubic), are selected, and the arrangement of the mixed lattice structure is determined to be X and Y type. Wherein:

[0046] (1) X-shaped unit cell arrangement: The mixed lattice structure consists of three layers from top to bottom. In each unit cell, the FCCs are arranged in an X-shape, occupying the four vertices and the center of the square, respectively. Figure 2 As shown in (a), the X-direction is perpendicular to the load direction. A mechanical support framework is formed by the FCC unit cells at the vertices and center, and the BCC unit cells fill the gaps, achieving a synergy between toughness and compressive strength.

[0047] (2) Y-type cell arrangement: such as Figure 2As shown in (b), the FCC cells in each unit cell are fixed in a Y-shape, occupying two vertices, one midpoint of an edge, and one body center of the square, respectively, with the Y-shaped direction perpendicular to the load direction. This asymmetric yet balanced arrangement further optimizes the stress transfer path and improves the structural stability under complex compressive loads.

[0048] like Figure 3 As shown, the dual-phase lattice hybrid structure in this embodiment is a cubic structure composed of 3×3×3 unit cells, with dimensions of 30mm×30mm×30mm, and the size of a single unit cell is 10mm×10mm×10mm. Node 1 is shared only by FCC unit cells; node 2 is shared only by BCC unit cells; the transition node is 1.5, shared by both FCC and BCC unit cells. In the Python code, a 3×3×3 regular grid structure is first established. Then, FCC and BCC unit cell types are alternately arranged in this regular grid structure, and the properties of each node are identified according to the type of the surrounding unit cells. Finally, the geometric information of all nodes is exported and saved as a .csv file.

[0049] like Figure 4 As shown in (a), to address the stress concentration problem caused by inconsistent rod diameters in unit cells of different phases, this embodiment employs a three-stage smooth transition method: large rod diameter, intermediate rod diameter, and small rod diameter. At the rod connection between the FCC and BCC unit cells, instead of a direct rigid joint, an intermediate rod diameter segment is inserted to form a gradient transition, ensuring a gradual change in the stress-bearing cross-section and thus avoiding abrupt stress changes. Figure 4 (b) Figure 4 (c) These are single-layer X-layout and single-layer Y-layout, respectively, after incorporating the transition design. Specifically:

[0050] 1. Preliminary information calibration: First, establish lattice node coordinates and type label files to complete the unified calibration of node spatial location, FCC / BCC cell region, and node attributes; then read the calibration data and identify the transition connection between FCC cell and BCC cell by node type. At this time, the starting end of the calibration transition segment is connected to the large rod diameter cell, and the ending end of the calibration transition segment is connected to the small rod diameter cell.

[0051] 2. Transition (Intermediate) Rod Diameter Calculation: Under the conditions of the same material, volume, and relative density, since the number of load-bearing rods in a BCC unit cell is less than that in an FCC unit cell, its load-bearing rod diameter must be larger. Therefore, the program automatically uses the average rod diameter at the connection point between the BCC and FCC unit cells to achieve a gradient transition, ensuring a smooth change in the cross-section. This is based on the initial large rod diameter input by the user. Custom input of the initial rod diameter Calculate the transition rod diameter using the average value method:

[0052]

[0053] Forming a three-stage transition rod diameter: .

[0054] In one specific implementation, the three-level transition code can be extended to a four-level smooth transition:

[0055]

[0056] Forming a four-stage transition rod diameter: .

[0057] Similarly, the n-stage smooth transition is "large rod diameter → multiple intermediate rod diameters → small rod diameter", and the formula for calculating the intermediate rod diameter is as follows:

[0058]

[0059] In the formula, This is the initial rod diameter; The initial rod diameter; This refers to the diameter of the intermediate rod.

[0060] 3. Volume Constraints and Iterative Adjustment: Based on the initial rod diameter and the intermediate rod diameter, the model is parametrically modeled. It is calculated whether the current model meets the lightweight requirements (i.e., the volume meets the maximum constraint). If the requirements are not met, the initial rod diameter is dynamically adjusted and the intermediate rod diameter is recalculated until the model volume meets the target volume requirements. Finally, the optimal three-stage transition rod diameter is output and the model is generated.

[0061] After designing the model using the interface transition optimization design method for the two-phase lattice hybrid crystal structure in this embodiment, the model was printed and experimental compression test results are as follows: Figure 5 As shown, the compressive strength, from largest to smallest, is as follows: X-layout with transition, Y-layout with transition, X-layout without transition, and Y-layout without transition. Specifically:

[0062] 1. Material Selection: Onyx (chopped carbon fiber reinforced nylon composite material) is used for 3D printing. Its parameters are shown in the table below:

[0063] Table 1. Main mechanical properties of Onyx printing material

[0064]

[0065] 2. Preparation equipment and process: Printer nozzle temperature 250℃, layer thickness 0.1mm, filling density according to crystal structure design parameters, protective gas is air.

[0066] 3. Overall target volume calculation: Cube volume 27000mm³ × lattice relative density 30% = 8100mm³.

[0067] 4. Cell arrangement: The X-type cell arrangement consists of 5 FCC cells per layer, distributed at the 4 vertices and center of the square in each layer, with BCC cells filling the remaining positions. The X direction is perpendicular to the compressive load direction. The Y-type cell arrangement consists of 4 FCC cells per layer, distributed at the 2 vertices, 1 center, and 1 edge midpoint of the square, with BCC cells filling the remaining positions. The Y direction is perpendicular to the compressive load direction.

[0068] 5. A total of four models were printed: a lattice with transition X arrangement, a lattice without transition X arrangement, a lattice with transition Y arrangement, and a lattice without transition Y arrangement. The printing results for the lattice models with transition X arrangement and transition Y arrangement are shown below. Figure 6 (a) and Figure 6 As shown in (b).

[0069] 6. Rod diameter parameters: After parametric modeling with the software Spaceclaim and iterative optimization with Python, the X-shaped mixed lattice structure converged to obtain a large rod diameter of 1.7 mm, a small rod diameter of 1.5 mm, and a middle rod diameter of 1.6 mm; after convergence, the Y-shaped mixed lattice structure yielded a large rod diameter of 1.8 mm, a small rod diameter of 1.6 mm, and a middle rod diameter of 1.7 mm.

[0070] 7. Compression test: The universal testing machine adopts the following... Figure 7 As shown. The compressive properties of four groups of samples (with transition X-type lattice, without transition X-type lattice, with transition Y-type lattice, and without transition Y-type lattice) were tested on a universal testing machine; the compression process of the sample without transition X-type lattice is as follows. Figure 8 As shown in (a), the compression process of the transitionless Y-structured lattice is as follows: Figure 8 As shown in (b).

[0071] 8. Test equipment and environment: A 100kN load sensor was selected, and the ambient temperature was 25℃ with a relative humidity of 50%.

[0072] 9. Loading and data acquisition conditions: The loading mode is controlled by a program, with a loading rate of 1.5 mm / min. The termination condition is that the displacement reaches 15 mm or the load reaches 98000 N (to protect the sensor); the data acquisition frequency is 30 Hz, and load and displacement data are acquired synchronously.

[0073] 10. Data processing and calculation:

[0074] (1) Stress ,in For load, cross-sectional area ;

[0075] (2) Strain ,in For compressive displacement, gauge length ;

[0076] (3) Elastic modulus

[0077] 11. Discussion of Test Results:

[0078] Depend on Figure 5 It can be seen that the compressive stress-strain curves of the four lattice structures all exhibit the typical characteristics of "elastic stage - yield strengthening stage - (partial) stress reduction stage", but the presence or absence of transition design and arrangement have a significant impact on the curve shape.

[0079] (1) Mixed lattice specimen with transitional X-arrangement: The three-stage variable rod diameter parameters are 1.7 mm, 1.6 mm (intermediate transition rod diameter), and 1.5 mm, respectively. Its stress-strain curve is shown below. Figure 5 As shown, when the strain is ≤5%, the elastic modulus is calculated to be 459.2 MPa through the effective linear segment of the stress-strain curve; when the strain reaches 15%, the measured compressive strength is 25.12 MPa, and the load is 22608 N. The stress distribution of the specimen is uniform, and there is no local buckling or fracture of the rod; when the strain reaches 49.98%, the specimen still does not fracture, but only shows stable strengthening, with a maximum stress of 30.58 MPa, and no significant decrease in fracture stress is observed.

[0080] (2) Mixed lattice specimens with no transition X arrangement: their stress-strain curves are as follows Figure 5 As shown, strain When the strain reaches 15%, the compressive strength is 19.38 MPa, and the load is 17442 N, which is about 23.0% lower than that with the transition X arrangement. When the strain reaches 34.0%, the rod at the connection point undergoes brittle fracture, with a corresponding fracture stress of 19.81 MPa, and the specimen loses its load-bearing capacity.

[0081] (3) Mixed lattice specimens with transitional Y-arrangement: The three-stage variable rod diameter parameters are 1.8 mm, 1.7 mm (intermediate transition rod diameter), and 1.6 mm. Their stress-strain curves are as follows: Figure 5 As shown, strain When the strain reaches 15%, the elastic modulus is measured to be 387.5 MPa; when the strain reaches 15%, the compressive strength is 20.98 MPa, and the load is 18882 N; when the strain reaches 49.98%, the specimen exhibits local buckling of the rod, with a corresponding maximum stress of 27.81 MPa.

[0082] (4) Mixed lattice specimens with no transition Y arrangement: their stress-strain curves are as follows Figure 5 As shown, when strain When the strain reaches 15%, the elastic modulus is 142.3 MPa; when the strain reaches 15%, the compressive strength is 14.61 MPa, corresponding to a load of 13149 N, which is 30.3% lower than that with the transition Y arrangement; when the strain reaches 33%, the rod at the connection point breaks, with a corresponding fracture stress of 13.57 MPa, and the specimen loses its load-bearing capacity.

[0083] The above experimental comparison shows that, compared with the structure without transition lattice, under the same strain conditions (when the strain reaches 15%), the compressive strength of the structure with transition X arrangement can reach more than 19.6 MPa, which is about 35% higher than that without transition X arrangement; the compressive strength of the structure with transition Y arrangement can reach 18.3 MPa, which is about 34% higher than that without transition Y arrangement.

[0084] In strain In the elastic stage, the elastic modulus of the X-type arrangement with transition is 125 MPa, a 40.4% increase compared to 89 MPa without transition; the elastic modulus of the Y-type arrangement with transition is 112 MPa, a 25.8% increase compared to the X-type arrangement without transition, and a 43.6% increase compared to the Y-type arrangement without transition. Simultaneously, the maximum fracture strain of the X-type arrangement with transition can reach over 35%, a 25% increase compared to the X-type arrangement without transition; the maximum fracture strain of the Y-type arrangement with transition can reach over 32%, a 28% increase compared to the Y-type arrangement without transition. After incorporating the variable rod diameter transition, the deformation and fracture resistance of the hybrid structure are significantly enhanced. Furthermore, it can be observed that under the same conditions, the hybrid lattice structure with X-type arrangement outperforms the Y-type arrangement.

[0085] In summary, under the premise of ensuring that the overall mass remains unchanged, the X / Y type unit cell arrangement with variable rod diameter transition design of the present invention can significantly improve the compressive strength and fracture resistance of the lattice structure, while greatly reducing the risk of local failure, thus achieving a balance between lightweight and high performance.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for optimizing the transition of the interface in a two-phase lattice hybrid crystal structure, characterized in that, Includes the following steps: S1. Select two different types of lattice structures and determine the arrangement of the mixed lattice structure; S2. Lattice Node Data Generation: Define the hybrid lattice structure size and the size of a single unit cell. The hybrid lattice structure is an n×n×n lattice structure, and set the shared type of each lattice node according to the arrangement. In the Python code, first establish a grid structure consistent with the hybrid lattice structure, then alternately arrange the two types of unit cells in the grid, and identify the properties of each node according to the surrounding unit cell types. Finally, export and save all node information. S3. Initialize rod diameter parameters and create initial model: Calculate the transition rod diameter based on the custom initial rod diameter parameters, and create a SpaceClaim executable modeling script from the node information, initial rod diameter parameters and transition rod diameter. Run the executable modeling script to create an initial model of the hybrid lattice structure and calculate the volume data of the initial model. S4. Determine whether the absolute difference between the calculated volume of the initial model and the target volume of the hybrid lattice structure meets the design requirements. If it does, then the initial rod diameter parameter is the optimal rod diameter parameter, and proceed to step S6; if it does not, proceed to step S5. S5. Iterative Optimization: Adjust the rod diameter parameters of the two types of unit cells respectively, and then recreate the SpaceClaim executable modeling script using the node information and the adjusted rod diameter parameters. Next, call the newly created executable modeling script to generate the model under the new rod diameter parameters and recalculate the model volume. Then, compare the updated model volume with the target volume to determine whether the absolute difference between the two meets the design requirements. If it does, proceed to step S6; if it does not, repeat this step iteratively until the absolute difference between the model volume and the target volume meets the design requirements or the model volume no longer changes. At this point, the adjusted rod diameter parameters are taken as the optimal rod diameter parameters, and the iterative cycle is completed. At this time, a transition connection is formed at the junction of the two types of unit cells. S6. Establish a 3D model: Save the optimal bar diameter parameters, automatically generate and save the hybrid lattice structure model based on the executable modeling script.

2. The optimization design method according to claim 1, characterized in that, In step S3, the transition rod diameters for the two types of unit cell connections are calculated using the average value method: in, For custom input of the initial rod diameter, The initial rod diameter is set to the user-defined input. This refers to the diameter of the transition rod.

3. The optimization design method according to claim 1, characterized in that, In step S4, the design requirement to be met is that the absolute difference between the calculated model volume and the target volume of the hybrid lattice structure is within 200 mm³.

4. The optimization design method according to claim 1, characterized in that, In step S5, the iterative adjustment of the rod diameter parameters of the two types of unit cells is as follows: if the calculated volume of the updated model is smaller than the target volume, the rod diameter of both types of unit cells is increased simultaneously; if the calculated volume of the updated model is larger than the target volume, the rod diameter of both types of unit cells is decreased simultaneously.

5. The optimization design method according to claim 1, characterized in that, The calibration method for cell transition connections in step S5 is as follows: First, establish lattice node coordinates and type label files to complete the unified calibration of node spatial positions, cell regions, and node attributes; then read the calibration data and identify the transition connection points of the two types of cells by node type; wherein, the starting end of the transition segment is connected to the large-diameter cell and the ending end of the transition segment is connected to the small-diameter cell.

6. The optimization design method according to claim 1, characterized in that, In step S1, the lattice structure includes, but is not limited to, simple cubic, diamond structure, face-centered cubic lattice and body-centered cubic lattice.

7. The optimization design method according to claim 1, characterized in that, In step S1, the arrangement of the mixed lattice structure includes, but is not limited to, H-type, I-type, □-type, X-type, and Y-type.

8. A two-phase lattice hybrid crystal structure, characterized in that, The dual-phase lattice hybrid crystal structure is designed using the optimization design method as described in any one of claims 1-7.

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