CN-121980833-A - Double-phase lattice mixed lattice structure and connection interface transition optimization design method thereof

CN121980833ACN 121980833 ACN121980833 ACN 121980833ACN-121980833-A

Abstract

The invention discloses a double-phase lattice mixed lattice structure and a connection interface transition optimization design method thereof, comprising the steps of selecting two different types of lattice structures and determining a mixed lattice structure arrangement mode; generating lattice structure node data, initializing rod diameter parameters, creating an initial model, calculating volume data of the initial model, judging that the absolute difference between the calculated volume of the model and the target volume meets the requirement, iteratively optimizing and adjusting the rod diameter parameters of a unit cell if the absolute difference does not meet the requirement, storing the optimal rod diameter parameters and building a three-dimensional model. According to the design method, the rod diameters among different unit cells are subjected to variable rod diameter transition design, so that local stress concentration is effectively avoided on the premise of ensuring the unchanged overall quality, the balance between light weight and high performance is realized, the compression mechanical property of a lattice structure is remarkably improved, and technical support can be provided for printing of the 3D printing structural member which needs to bear compression load.

Inventors

DING CHENG
MOU CHUNXIAO
LI YIBO
HUANG MINGHUI

Assignees

中南大学

Dates

Publication Date: 20260505
Application Date: 20260408

Claims (8)

1. The transition optimization design method for the connection interface of the double-phase lattice mixed lattice structure is characterized by comprising the following steps of: S1, selecting two different types of lattice structures, and determining the arrangement mode of the mixed lattice structures; S2, generating lattice node data, namely defining a mixed lattice structure size and a single cell size, wherein the mixed lattice structure is an n multiplied by n lattice structure, and setting sharing types of lattice nodes according to an arrangement mode; S3, initializing a rod diameter parameter and creating an initial model, namely calculating a transition rod diameter according to the self-defined initial rod diameter parameter, creating SPACECLAIM an executable modeling script according to the node information, the initial rod diameter parameter and the transition rod diameter, operating the executable modeling script to create the initial model of the mixed lattice structure, and calculating the volume data of the initial model; S4, judging whether the absolute difference value between the calculated volume of the initial model and the target volume of the mixed lattice structure meets the design requirement, if so, proving that the initial rod diameter information is the optimal rod diameter parameter, and executing the step S6; s5, iterative optimization, namely respectively adjusting the rod diameter parameters of the two types of unit cells, re-creating SPACECLAIM an executable modeling script by using node information and the adjusted rod diameter parameters, then calling the newly created executable modeling script to generate a model under the new rod diameter parameters, and re-calculating the model volume, then comparing the updated model volume with the target volume, judging whether the absolute difference value of the updated model volume and the target volume meets the design requirement, and executing the step S6 if the absolute difference value of the updated model volume and the target volume meets the design requirement, and repeating the iterative process until the absolute difference value of the model volume and the target volume meets the design requirement or the model volume is not changed any more, and completing an iterative cycle; and S6, establishing a three-dimensional model, namely saving the optimal rod diameter parameter, automatically generating a mixed lattice structure model based on the executable modeling script, and saving the mixed lattice structure model.
2. The optimization design method according to claim 1, wherein in step S3, the transition rod diameters of the two types of unit cell connections are calculated by an average method: Wherein, the An initial large rod diameter for user-defined input, For the initial small diameter of the custom input, Is the diameter of the transition rod.
3. The method according to claim 1, wherein in step S4, the design requirement to be satisfied is that the absolute difference between the calculated model volume and the target volume of the mixed lattice structure is within 200mm 3.
4. The method of optimizing design according to claim 1, wherein in step S5, the iterative adjustment of the rod diameter parameters of the two types of unit cells is performed by increasing the rod diameters of the two types of unit cells simultaneously if the calculated volume of the updated model is smaller than the target volume, and decreasing the rod diameters of the two types of unit cells simultaneously if the calculated volume of the updated model is larger than the target volume.
5. The optimization design method according to claim 1, wherein the calibration method of the cell transition connection in the step S5 is characterized in that lattice node coordinates and type marking files are established firstly to finish unified calibration of node space positions, cell areas and node attributes, calibration data are read, and transition connection positions of two types of cells are identified through node types, wherein a starting end of a transition section is connected with a large-rod-diameter cell, and a terminating end of the transition section is connected with a small-rod-diameter cell.
6. The method of claim 1, wherein in step S1, the lattice structure includes, but is not limited to, simple cubes, diamond structures, face-centered cubic lattices, and body-centered cubic lattices.
7. The method according to claim 1, wherein in step S1, the arrangement of the dual-phase hybrid lattice includes, but is not limited to, H-type, i-type, mouth-type, X-type and Y-type.
8. A dual-phase lattice mixed lattice structure, characterized in that the dual-phase lattice mixed lattice structure is designed by the optimum design method according to any one of claims 1 to 7.

Description

Double-phase lattice mixed lattice structure and connection interface transition optimization design method thereof Technical Field The invention relates to the technical field of 3D printing, in particular to a biphase lattice mixed lattice structure and a connection interface transition optimization design method thereof. Background The 3D printing lattice structure is a light high-strength space network formed by nodes and connecting rods, and material performance optimization is realized through periodic unit arrangement. The method breaks through the traditional manufacturing limitation, can precisely form complex internal geometric forms, remarkably lighten the weight and improve the energy absorption, heat dissipation and biocompatibility. The main types include planar lattices, truss lattices and TPMS lattices with excellent performance, are widely applied to aerospace lightweight components, medical bone implants and sports shoe sole buffer designs, and are core technologies for enabling high-end equipment and functional materials in additive manufacturing. The existing 3D printing lattice structure mainly comprises a single lattice structure and two kinds of lattice structures with the same rod diameter: 1. The core design logic for a single lattice structure is "single cell formation priority", e.g., selecting only one cell of FCC or BCC as a building block, the overall lattice structure is generally designed as a regular cube of n x n unit cells, with individual unit cell dimensions being uniform. The single lattice structure cannot meet the comprehensive bearing requirements under the compression working condition, such as strong toughness but insufficient compressive strength of pure FCC lattice, excellent compressive property but limited toughness of pure BCC lattice, and difficulty in fully exerting the performance advantages of the material. 2. The mixed lattice structure with the same rod diameter directly uses the rod diameter parameters of a single lattice, and the problem of inconsistent rod diameters of different phases is considered, so that local stress concentration at the joints of different unit cells is caused. Therefore, the biphase mixed lattice structure is easy to crack, locally fail and the like under the compression working condition, and the service life of the structure is seriously influenced. In order to avoid the occurrence of the difference of the rod diameters, the prior art generally unifies the dimensions by sacrificing the structural performance of the mixed crystal (reducing the rod diameter), increasing the total mass (increasing the rod diameter), and the like, which easily causes the weakening of local mechanical properties and breaks against the original purpose of lightweight design. Therefore, a transition optimization design method for the connection interface of the dual-phase lattice mixed lattice structure is needed in the industry, the compression mechanical property of the lattice structure is improved on the premise of ensuring the total quality to be unchanged, and more reliable technical support is provided for the 3D printing structural member which needs to bear compression load. Disclosure of Invention The invention provides a transition optimization design method for a connection interface of a double-phase lattice mixed lattice structure, which aims to overcome the problems in the background technology. In order to achieve the above purpose, the invention provides a transition optimization design method for a connection interface of a dual-phase lattice mixed lattice structure, which comprises the following steps: s1, selecting two different types of lattice structures according to design requirements, and determining an arrangement mode of a mixed lattice structure; S2, in the python software, firstly defining the size of a single unit cell in the lattice structure and the size of the mixed lattice structure, defining the mixed lattice structure as an n multiplied by n lattice structure, mixing the lattice structures and setting the unit cell sharing type of each lattice node according to an arrangement mode, establishing a regular lattice structure consistent with the mixed lattice structure, then alternately arranging two types of unit cells in the regular lattice structure, marking the property of each node according to the type of unit cell around the node, and finally deriving and storing all node information as A file; S3, calculating a transition rod diameter according to the self-defined initial rod diameter information, creating SPACECLAIM an executable modeling script according to the node information, the initial rod diameter parameter and the transition rod diameter obtained in the step S2, running the executable modeling script to create an initial model of the mixed lattice structure, and calculating volume data of the initial model; S4, judging whether the absolute difference value between the calculated volume of the initial m