CN120180530A - TPMS sheet and rod-shaped hybrid lattice structure and its generation method - Google Patents
TPMS sheet and rod-shaped hybrid lattice structure and its generation method Download PDFInfo
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Abstract
本发明公开了一种TPMS片层与杆状混合点阵结构及其生成方法，涉及材料结构设计领域，方法包括：S1，选择要连接的TPMS片层结构类型和杆状结构类型；S2，根据选择的杆状结构类型选择TPMS骨架结构类型；S3，根据选择的TPMS片层结构类型和TPMS骨架结构类型生成TPMS片层结构和TPMS骨架结构，利用TPMS片层结构和TPMS骨架结构的函数生成两个结构的过渡结构，使用过渡结构桥接两种结构得到中间结构；S4，根据选择的杆状结构类型生成杆状结构对中间结构的非过渡区进行替换，得到包括依次连接的TPMS片层结构、过渡结构和杆状结构的TPMS片层与杆状混合点阵结构。本发明通过识别TPMS骨架结构与杆状结构的边界分布相似性生成过渡结构，实现了TPMS片层与杆状结构的连续柔顺连接。
The present invention discloses a TPMS sheet and rod-shaped hybrid lattice structure and a generation method thereof, which relates to the field of material structure design. The method comprises: S1, selecting a TPMS sheet structure type and a rod-shaped structure type to be connected; S2, selecting a TPMS skeleton structure type according to the selected rod-shaped structure type; S3, generating a TPMS sheet structure and a TPMS skeleton structure according to the selected TPMS sheet structure type and TPMS skeleton structure type, generating a transition structure of the two structures using functions of the TPMS sheet structure and the TPMS skeleton structure, and bridging the two structures using the transition structure to obtain an intermediate structure; S4, generating a rod-shaped structure according to the selected rod-shaped structure type to replace a non-transition region of the intermediate structure, and obtaining a TPMS sheet and rod-shaped hybrid lattice structure including a TPMS sheet structure, a transition structure and a rod-shaped structure connected in sequence. The present invention generates a transition structure by identifying the similarity of the boundary distribution of the TPMS skeleton structure and the rod-shaped structure, thereby realizing a continuous and compliant connection between the TPMS sheet and the rod-shaped structure.
Description
Technical Field
The invention relates to the field of material structure design, in particular to a TPMS (tire pressure monitor system) sheet and rod-shaped mixed lattice structure and a generation method thereof.
Background
The engineering lattice structure has wide application potential in the fields of biomedical engineering, automobile industry and the like. The core challenge is to realize specific mechanical and functional characteristics through microstructure optimization. The traditional design depends on reasonable configuration of microstructures, the lattice structure with the traditional single topological form has great limitation (such as the theoretical limit of rigidity and strength of a Plate nano lattice is mentioned in the document of Plate-nanolattices at the theoretical limit of STIFFNESS AND STRENGTH), the limitation of the single morphological structure is broken through to realize more full utilization of design space provided by additive manufacturing, namely, a rod-shaped lattice (such as BCC and FCC) has definite bending/stretching dominant mechanical behavior, but interface mutation is easy to cause stress concentration, and a surface structure (such as TPMS) has continuous self-supporting characteristic and excellent mechanical property based on a triple-period minimum curved surface, but lacks structural adaptability. The mixed lattice structure can realize the collaborative optimization of the performance of multiple physical fields by integrating the dominant mechanical characteristics of different structure types. However, as the rod-shaped crystal lattice and the surface-shaped crystal lattice have differences in geometric forms, characteristic sizes, space distribution rules and the like, geometric discontinuities and characteristic size differences often exist at the connecting interface, the incompatibilities not only can cause remarkable stress concentration effect, but also increase the process complexity in the additive manufacturing process, and structural defects or mechanical property degradation easily occur at the interface.
Existing solutions improve hybrid structural integrity (as studied in document "Functionally graded lattice structures for energy absorption: Numerical analysis and experimental validation") mainly by means of functional gradient strategies (e.g. rod diameter grading, unit cell scaling), but porosity variations within a single topology can lead to limited mass transport or manufacturing defects. While multi-structure hybrid designs extend the design freedom through spatial heterostructures, the geometrical incompatibility problem of different lattice interfaces is prominent. For example, the mathematical surface definition of TPMS supports smooth transitions, but the rod-like structure lacks continuous mathematical characterization, resulting in stress concentrations and manufacturing difficulties in the connection region. Traditional interpolation or transition cell methods are high in computational cost and limited in effect, and are difficult to meet the requirements of complex applications.
Disclosure of Invention
Aiming at the problems, the invention provides the TPMS sheet and rod-shaped mixed lattice structure and the generation method thereof, and the generation method of the TPMS sheet and rod-shaped mixed lattice structure designs the transition structure of the TPMS sheet and rod-shaped mixed lattice structure by identifying the node similarity of the TPMS framework and the rod-shaped structure, so that the continuous flexible connection of the TPMS sheet and the rod-shaped structure is realized, the limitation of simple array design is avoided, and the difficult problems of geometric compatibility and mechanical compatibility among heterostructures are solved.
On the one hand, the TPMS sheet and rod-shaped mixed lattice structure generating method comprises the following specific steps:
S1, selecting a TPMS lamellar structure type and a rod-shaped structure type to be connected, wherein each transition connection node on a transition boundary of a single cell of the rod-shaped structure type meets a vertex condition, a corner condition or a face-centered condition, wherein the vertex condition is that the transition connection node is positioned at the vertex position of a single cell cube, the corner condition is that the transition connection node is positioned at the midpoint position of a corner of the single cell cube, the face-centered condition is that the transition connection node is positioned at the face center point position of the single cell cube, the single cell cube is a cube shape formed by all boundaries of single cells of the rod-shaped structure and adjacent single cells, the transition boundary is the boundary of the single cell cube facing the TPMS lamellar structure to be connected, and the transition connection node is the intersection point of the single cell of the rod-shaped structure and the transition boundary;
S2, selecting a TPMS framework structure type according to the selected rod-shaped structure type, wherein the TPMS framework structure type comprises an I-WRAPPED PACKAGE structure, a Neovius structure and a PRIMITIVE structure, selecting an I-WRAPPED PACKAGE structure if all transition connection nodes of the rod-shaped structure type meet the vertex condition, selecting a Neovius structure if all transition connection nodes of the rod-shaped structure type meet the edge condition, selecting a PRIMITIVE structure if all transition connection nodes of the rod-shaped structure type meet the face center condition, selecting a condition met by one transition connection node as a condition met by all transition connection nodes if all transition connection nodes meet different conditions, and selecting a corresponding TPMS framework structure type;
S3, generating a TPMS lamellar structure and a TPMS framework structure according to the selected TPMS lamellar structure type and the TPMS framework structure type, generating a transition structure of the two structures by utilizing functions of the TPMS lamellar structure and the TPMS framework structure, and bridging the TPMS lamellar structure type and the TPMS framework structure by utilizing the transition structure to obtain an intermediate structure, wherein the intermediate structure comprises the TPMS lamellar structure, the transition structure with unit cell thickness and the TPMS framework structure which is used as a non-transition area which are sequentially connected;
and S4, generating a rod-shaped structure according to the selected rod-shaped structure type, and replacing a non-transition region of the intermediate structure to obtain the TPMS sheet-rod-shaped mixed lattice structure comprising the TPMS sheet structure, the transition structure with unit cell thickness and the rod-shaped structure which are sequentially connected.
Preferably, the rod-shaped structure types comprise SC, BCC, SC-BCC hybrid, NP1, iso truss, rhombic dodecahedron, auxetic, measured cube, OCT and CC, wherein SC, BCC, SC-BCC hybrid, NP1, iso truss and Rhombic dodecahedron meet vertex conditions, auxetic and measured cube meet edge conditions, and OCT and CC meet face center conditions.
Preferably, the TPMS lamellar structure type includes a TPMS P lamellar lattice structure, a TPMS G lamellar lattice structure, a TPMS D lamellar lattice structure and a TPMS I-WP lamellar lattice structure.
Preferably, the function of the transition structure is expressed as:
;
Wherein, A function representing a transition structure; Is the first A function of a TPMS lamellar structure or TPMS skeleton structure,,Representing the number of superimposed functions, n=2; Representation of Weight parameters of each TPMS lamellar structure or TPMS skeleton structure control continuous transition among the structures.
Preferably, the method comprises the steps of,Expressed as:
;
;
wherein k represents a constant for controlling the length of the transition section; representation points And the firstA distance function of a laminated structure of each TPMS or a skeleton structure of each TPMS,Representation pointsRepresentation and the firstA distance function of each TPMS lamellar structure or TPMS skeleton structure is used for controlling the boundary of the function; representing the coordinates of point clouds formed by the boundary of the jth TPMS lamellar structure or TPMS skeleton structure; representing the coordinates of the points in space in a cartesian coordinate system.
Preferably, the mathematical expressions of each type of TPMS framework structure are as follows:
;
;
;
Wherein, A function representing the framework structure of I-WRAPPED PACKAGE TPMS; a function representing Neoviuse TPMS skeletal structures; a function representing PRIMITIVE TPMS skeletal structures; Representing coordinates of points in space in a Cartesian coordinate system; 、 And Constant parameters controlling the period of the framework structures I-WRAPPED PACKAGE, neovius and PRIMITIVE TPMS are shown respectively.
Preferably, after S4, the method further comprises the following steps:
s5, using additive manufacturing technology to generate the real object with the TPMS sheet and rod-shaped mixed lattice structure.
On the other hand, the TPMS slice and rod-shaped mixed lattice structure generated by the TPMS slice and rod-shaped mixed lattice structure generation method comprises the steps of SC, BCC, SC-BCC hybrid, NP1, iso truss, rhombic dodecahedron, auxetic, truncated cube, OCT and CC, wherein the used TPMS slice structure type comprises a TPMS P slice lattice structure, a TPMS G slice lattice structure, a TPMS D slice lattice structure and a TPMS I-WP slice lattice structure, and 40 TPMS slice and rod-shaped mixed lattice structures are generated by the combination of the rod-shaped structure type and the TPMS slice structure type.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the invention, the transition structure is introduced by matching boundary distribution characteristics of the TPMS framework and the rod-shaped structure, so that geometric compatibility of two heterogeneous lattices is realized, abrupt change and discontinuity at the interface of the traditional mixed structure are eliminated, smooth transition from the TPMS sheet layer to the supporting structure is ensured, stress concentration is effectively avoided, structural integrity is improved, and the method is particularly suitable for complex geometric adaptation scenes such as bone-tendon interfaces and the like;
(2) The mixed lattice structure generated by the invention integrates the high specific surface area of the TPMS and the adjustable rigidity characteristic of the rod-shaped structure, realizes the cooperative optimization of multiple physical properties, can be used in a bionic bone-tendon structure, meets the dual requirements of mechanics and material transmission in tissue regeneration, and can be further expanded to stress buffering components in aerospace lightweight structures or precision machinery;
(3) The invention can imitate and construct a natural bone-fibrocartilage-tendon structure through gradual change design from TPMS (bone-like) to rod-like structure (tendon-like), solves the difficult problem of large difference of bone and tendon geometry, realizes good adaptation, has strong bearing capacity, can effectively disperse mechanical load, improves structural integrity, has uniform strain distribution, small strain concentration at an interface, has high structural stability, has modulus gradient conforming to the transition range of the natural bone-tendon, has enhanced tensile rigidity, has great potential in the biomedical field, and particularly has the application of tendon-bone repair implants, and is expected to improve the treatment effect.
(4) The invention directly generates the physical model by the generated TPMS sheet and rod-shaped mixed lattice structure through additive manufacturing technology (such as 3D printing), and provides a multifunctional lattice design scheme with high strength and high adaptability in the fields of biomedical implants (such as bone-tendon interfaces), structural engineering and the like.
Drawings
The invention is described in further detail below with reference to the accompanying drawings;
FIG. 1 is a flowchart of a method for generating a TPMS sheet and rod-shaped hybrid lattice structure;
Fig. 2 is a schematic view of a TPMS sheet-rod-shaped mixed lattice structure and a method for generating the same, wherein (a) is a schematic view of a TPMS P sheet lattice unit structure, (b) is a schematic view of a TPMS G sheet lattice unit structure, (c) is a schematic view of a TPMS D sheet lattice unit structure, and (D) is a schematic view of a TPMS I-WP sheet lattice unit structure;
Fig. 3 is a schematic diagram of a rod structure of a TPMS sheet and rod mixed lattice structure generating method, in which (a) is a schematic diagram of a rod structure with similar nodes in a prior art and I-WRAPPED PACKAGE TPMS framework unit cell structure, (b) is a schematic diagram of a rod structure with similar nodes in a prior art and Neovius TPMS framework unit cell structure, and (c) is a schematic diagram of a rod structure with similar nodes in a prior art and PRIMITIVE TPMS framework unit cell structure;
Fig. 4 is a schematic view of a TPMS framework unit cell structure of a TPMS sheet and rod-shaped mixed lattice structure generating method, wherein (a) is a schematic view of an I-WRAPPED PACKAGE TPMS framework unit cell structure, (b) is a schematic view of a Neovius TPMS framework unit cell structure, and (c) is a schematic view of a PRIMITIVE TPMS framework unit cell structure;
fig. 5 is a schematic diagram of a transition structure generated by a TPMS G lamellar structure and an I-WRAPPED PACKAGE TPMS skeleton lattice structure according to the first embodiment;
fig. 6 is a schematic diagram of a TPMS sheet and rod mixed lattice structure generated by a TPMS G sheet lattice structure and a BCC rod lattice structure according to the first embodiment;
Fig. 7 is a mixed lattice structure of a TPMS G sheet lattice structure and a CC rod lattice structure connected to each other in the second embodiment;
Fig. 8 is a schematic diagram of a mixed lattice structure in which a TPMS G sheet lattice structure and a measured cube rod lattice structure are connected.
Detailed Description
The invention is further described below by means of specific embodiments.
As shown in fig. 1, a TPMS sheet and rod-shaped mixed lattice structure generating method specifically includes the following steps:
s1, selecting a laminated structure type and a rod-shaped structure type of the TPMS to be connected.
As shown in fig. 2, the unit cell types of the TPMS sheet structure of the present embodiment include (a) a TPMS P sheet lattice unit cell structure shown in (b) a TPMS G sheet lattice unit cell structure shown in (c) a TPMS D sheet lattice unit cell structure shown in (D) and (D) a TPMS I-WP sheet lattice unit cell structure shown in (D).
As shown in fig. 3, the unit cell types of the rod-like structure include SC (Simple cube) shown in (a) -1, BCC (Body-Centered Cubic, body cube) shown in (a) -2, SC-BCC hybrid shown in (a) -3, NP1 shown in (a) -4, iso truss (fiber wound lattice beam) shown in (a) -5, rhombic dodecahedron (rhombohedral dodecahedron) shown in (a) -6, auxetic (auxetic material) shown in (b) -1, truncated cube) shown in (b) -2, OCT (Octahedron, octahedral structure) shown in (c) -1, and CC structure shown in (c) -2.
It should be noted that, the unit cell type of the TPMS lamellar structure may be selected from other unit cell types of the TPMS lamellar structure, and the unit cell type of the rod-shaped structure may be selected from other types meeting the connection condition, which is specifically set according to the need, and the embodiment is not limited.
S2, selecting the TPMS framework structure type according to the selected rod-shaped structure type.
And selecting the TPMS framework structure type with similar node distribution characteristics with the rod-shaped structure at the structure boundary as a twin crystal unit. The TPMS skeleton structure with similar node distribution characteristics refers to a structure with similar node distribution characteristics at a structure boundary, and node distribution characteristics of most structures are summarized into three categories, namely nodes are distributed on eight vertexes, midpoints of edges and central points of faces of a cube, the cube is composed of structure boundaries of unit cells and adjacent unit cells, and the structure boundary refers to the boundary of the cube facing to a TPMS lamellar structure to be connected.
As shown in fig. 4, these three types correspond to three TPMS framework structures I-WRAPPED PACKAGE, neovius, and PRIMITIVE, respectively, and therefore, these three TPMS framework structures are taken as twin units, and their mathematical expressions are:
;
;
;
Wherein, A function representing the framework structure of I-WRAPPED PACKAGE TPMS; a function representing Neoviuse TPMS skeletal structures; representing PRIMITIVE TPMS functions of the skeletal structure, x, y and z are coordinates of points in space in a cartesian coordinate system, 、AndConstant parameters controlling the period of the framework structures I-WRAPPED PACKAGE, neovius and PRIMITIVE TPMS respectively.
Specifically, FIG. 3 (a) shows a single cell structure of a rod-like structure having similar nodes to the framework single cell structure of I-WRAPPED PACKAGE TPMS in the prior art, which is SC, BCC, SC-BCC hybrid, NP1, iso truss and Rhombic dodecahedron, respectively. Fig. 3 (b) shows a prior art unit cell structure having a rod-like structure with similar nodes to the Neovius TPMS skeleton unit cell structure, auxetic and measured cube, respectively. In FIG. 3, (c) shows the prior art unit cell structure with similar nodes to the PRIMITIVE TPMS skeleton unit cell structure, OCT and CC, respectively.
The method comprises the steps of selecting a TPMS framework structure from I-WRAPPED PACKAGE structures if all nodes of connecting structure boundaries of a selected rod-shaped structure are located at the vertex positions of a cube, selecting a Neovius structure if all nodes of all connecting structure boundaries of the rod-shaped structure are distributed at the central point positions of edges of the cube, selecting a PRIMITIVE structure if all nodes of all connecting structure boundaries of a rod-shaped structure type are distributed at the face center positions of the cube, and selecting a TPMS framework structure corresponding to the distribution position of any node of the connecting structure boundaries of the rod-shaped structure if all nodes of the connecting structure boundaries are distributed at different positions of the cube.
And S3, generating a TPMS lamellar structure and a TPMS framework structure according to the selected TPMS lamellar structure type and the TPMS framework structure type, generating a transition structure of the two structures by utilizing functions of the TPMS lamellar structure and the TPMS framework structure, and bridging the TPMS lamellar structure type and the TPMS framework structure by utilizing the transition structure to obtain an intermediate structure.
The intermediate structure comprises a TPMS lamellar structure, a transition structure with unit cell thickness and a TPMS framework structure serving as a non-transition region which are sequentially connected.
The functional expression of the transition structure is as follows:
;
Wherein, Is the firstA function of the skeleton structure of each TPMS,,Representing the number of superimposed TPMS framework structures; for the spatially dependent weight parameters, successive transitions between structures are defined, in this embodiment n=2.
Weight parameterDetermined by the Sigmoid transition function, expressed as:
;
wherein k represents a constant for controlling the length of the transition zone, and Representation pointsRepresentation and the firstThe distance function of each lattice structure, used for controlling the boundary of the function, is determined by the point cloud Pj (xj, yj, zj) formed by the structure boundary, and is expressed as:
;
Wherein, Representing a point cloudIs defined by the coordinates of (a).
And S4, generating a rod-shaped structure according to the selected rod-shaped structure type, and replacing a non-transition region of the intermediate structure to obtain the TPMS sheet-rod-shaped mixed lattice structure comprising the TPMS sheet structure, the transition structure with unit cell thickness and the rod-shaped structure which are sequentially connected.
The 40 TPMS sheet and rod mixed lattice structures can be generated by combining 10 rod structure types and 4 TPMS sheet structure types.
Embodiment one:
The hybrid architecture connection scheme proposed in this embodiment is not obtained by a simple array of unit structures, so that it is necessary to design and model all units in the design domain one by one, and manual implementation by means of general commercial modeling software would be a complex and time-consuming task. Therefore, the embodiment satisfies the manufacturing of the integrated design by writing MATLAB codes (other codes with similar programming logic belong to the protection category of the application) instead of manual and automatic distributed design space structures, so as to realize the hybrid lattice structure design and establish the manufacturing file capable of being directly 3D printed and the INP file for simulation. The method comprises the following steps:
1) Defining a design domain;
2) Defining structures of different areas, including rod-shaped structures and TPMS lamellar structures;
3) Generating a voxel matrix of the mixed structure;
4) The voxel matrix is converted into an INP and STL file.
Specifically, the size of the mixed structure is defined by its design domain, which includes two sub-regions respectively representing two rod-like structures to be mixed and a TPMS lamellar structure, and the two design domains are described by using the space occupied by the three-dimensional model in two stl format, and the two design domains are described by using the same coordinate system, and when the structure is generated, an extended cuboid is constructed by using the maximum size of the design domain in the coordinate axis direction (assuming a length, The design domains, L D、 BD and H D respectively, are wide and high, and then, according to a given precision (the number of voxels N u contained in each unit cell side length L u), the whole design domain is converted into a matrix (containing N elements, N=L DBDHD/(Lu/nu)), and the design domains corresponding to different structural types are given different values as "identity tags" for computer recognition and processing (e.g. integer 1, 1), 2 and 3, all voxel units in the design domain of the rod-shaped structure are assigned to be '1', all voxel units in the design domain of the TPMS lamellar structure are assigned to be '2', the transition area (connection boundary) identified later is assigned to be '3', the global design domain is searched by taking a unit matrix consisting of n u 3 elements as a step length from the origin of a coordinate system, the connection boundary of the two types of structures is identified (the boundary identification is realized through the space intersection operation of a numerical matrix, namely, when numerical labels of the two structures exist in one unit at the same time, the boundary area is judged), n u 3 elements containing the boundary are extracted as the design domain of the transition unit, and new values are assigned as the 'identity label' of the transition area. And then generating a corresponding structure according to the values of the identity labels of the elements in different areas of the matrix in the design domain, wherein the value of the rod diameter or the wall thickness of the transitional unit cell is equal to the value of the rod-shaped or TPMS lamellar structure connected adjacently at that position, so that the connection flexibility is ensured, and meanwhile, the relative density can be controlled in a range similar to that of the adjacent structure. And finally, carrying out Boolean cross operation on the generated cuboid structure and the geometric shape of the initial design domain, thereby finally obtaining the mixed structure meeting the given geometric shape.
The transition structure generation is realized by superposing two different TPMS skeleton structure functions (skeleton structures corresponding to the target TPMS lamellar structure topology and TPMS skeleton structures serving as twin crystal units) by using weight parameters, and then removing the material of the design domain where the target TPMS lamellar structure is located by Boolean subtraction, namely performing Boolean subtraction with one TPMS skeleton structure with the same topology and smaller relative density, and converting the material into the lamellar structure.
The "voxel" in this embodiment is a concept in which a voxel is expressed by an element value in a matrix, and one voxel corresponds to one element value. In computer processing, structures in space are expressed in a matrix, e.g., a value of 1 for a certain position of the matrix indicates that the voxel at that position is an entity and that 0 is null. The three-dimensional structure can thus be expressed mathematically in a matrix. When generating the structural model, the STL file is converted into a voxelized image, and the design domain is discretized into voxels.
In this embodiment, a lattice structure formed by the array of rod-shaped unit cells (i.e., BCC) shown in fig. 3 (a) -2 and a lattice structure formed by the unit cells of TPMS (i.e., TPMS G) shown in fig. 2 (b) are selected for connection.
And selecting a TPMS framework structure with similar nodes with BCC, namely an I-WRAPPED PACKAGE TPMS framework unit cell structure, wherein a transition unit cell is generated by expressing a TPMS lamellar structure generated by the I-WRAPPED PACKAGE TPMS framework unit cell structure and TPMS G by a mathematical function, and finally generating a TPMS G lattice and I-WRAPPED PACKAGE lattice intermediate structure 1 shown in figure 5, wherein the TPMS G lattice and I-WRAPPED PACKAGE lattice intermediate structure comprises a TPMS G lattice 11, a TPMS G lattice and BCC lattice transition structure 12 and an I-WRAPPED PACKAGE TPMS framework non-transition region 13 which are sequentially connected.
The selected BCC lattice 21 is used for replacing the non-transition region 13 of the I-WRAPPED PACKAGE TPMS framework, and the finally obtained complete mixed structure is shown in fig. 6, so that the mixed structure 2 of the TPMS G lattice and the BCC lattice is obtained, wherein the mixed structure comprises the TPMS G lattice 11, the TPMS G lattice and the BCC lattice transition structure 12 and the BCC lattice 21 which are sequentially connected.
The twin unit cell design in the method realizes geometric compatibility of two heterogeneous lattices by matching node characteristics of the TPMS framework and the supporting structure. For example, the introduction of the transition unit eliminates abrupt changes and discontinuities at the interface of the conventional hybrid structure, ensuring a smooth transition from the TPMS sheet to the support structure. The design effectively avoids stress concentration, improves structural integrity, and is particularly suitable for complex geometric adaptation scenes such as bone-tendon interfaces and the like;
The method realizes the collaborative optimization of multiple physical properties by integrating the high specific surface area of the TPMS and the adjustable rigidity of the rod-shaped structure. For example, in a bionic bone-tendon structure, the gradient design enables the rigidity to change 84 times, and meanwhile, the specific surface area gradient is maintained, so that the dual requirements of mechanics and material transmission in tissue regeneration are met. In addition, the strategy can be extended to stress buffering components in aerospace lightweight structures or precision machinery.
The method aims at the difficult problem of mechanical gradient of a natural tissue interface, and the strategy can imitate and construct a natural bone-fibrocartilage-tendon structure through gradual change design from TPMS (bone like) to rod-like structure (tendon like), so that the difficult problem of large difference of bone and tendon geometric shapes is solved, and good adaptation is realized. The bearing capacity is strong, the mechanical load can be effectively dispersed, and the structural integrity is improved. The strain distribution is uniform, the strain concentration at the interface is small, and the structural stability is high. And the modulus gradient of the structure accords with the transition range of natural bone-tendon, the tensile rigidity is enhanced, and the structure has great potential in the biomedical field, especially in the application of tendon-bone repair implants, and is expected to improve the treatment effect.
The method is characterized in that the node similarity of the TPMS framework and the rod-shaped structure is identified, twin cells are designed to serve as transition units, and the voxel principle and compensation optimization are combined, so that continuous flexible connection of the TPMS sheet layer and the rod-shaped structure is realized, and the limitation of simple array design is avoided. The novel hybrid connection strategy not only solves the difficult problem of geometric and mechanical compatibility among heterostructures, but also directly generates a model through 3D printing, and provides a multifunctional lattice design scheme with high strength and high adaptability in the fields of biomedical implants (such as bone-tendon interfaces), structural engineering and the like.
Embodiment two:
the main steps of this embodiment are the same as those of the first embodiment, except that a TPMS G sheet lattice structure and a CC rod lattice structure are selected for connection, so as to obtain a mixed structure of the TPMS G sheet lattice structure and the CC rod lattice structure, namely, a TPMS G and CC mixed lattice structure 3, which is shown in fig. 7, and includes a TPMS G lattice 11, a TPMS G lattice and CC lattice transition region 31, and a CC lattice 32.
Embodiment III:
The main steps of this embodiment are the same as those of the first embodiment, except that a TPMS G sheet lattice structure is selected to be connected with a Truncated cube rod lattice structure, so as to obtain a mixed structure of the TPMS G sheet lattice structure and the Truncated cube rod lattice structure, namely a TPMS G and Truncated cube mixed lattice structure 4, which is shown in fig. 8 and includes a TPMS G lattice 11, a TPMS G lattice and Truncated cube lattice transition region 41, and a Truncated cube lattice 42.
The foregoing is merely illustrative of specific embodiments of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modification of the present invention by using the design concept shall fall within the scope of the present invention.
Claims (8)
1. The TPMS sheet and rod-shaped mixed lattice structure generation method is characterized by comprising the following steps of:
S1, selecting a TPMS sheet structure type and a rod-shaped structure type to be connected, wherein the rod-shaped structure type meets the vertex condition, the edge condition or the face-centered condition, each transition connection node on the transition boundary of a single cell of the rod-shaped structure type meets the vertex condition, the edge condition or the face-centered condition, the vertex condition is that the transition connection node is positioned at the vertex position of a single cell cube, the edge condition is that the transition connection node is positioned at the midpoint position of the edge of the single cell cube, the face-centered condition is that the transition connection node is positioned at the center point position of the face of the single cell cube, the single cell cube is a cube shape formed by all boundaries of single cells of the rod-shaped structure and adjacent single cells, the transition boundary is the boundary of the single cell cube facing the TPMS sheet structure to be connected, and the transition connection node is the intersection point of the single cell of the rod-shaped structure and the transition boundary;
S2, selecting a TPMS framework structure type according to the selected rod-shaped structure type, wherein the TPMS framework structure type comprises an I-WRAPPED PACKAGE structure, a Neovius structure and a PRIMITIVE structure, selecting an I-WRAPPED PACKAGE structure if all transition connection nodes of the rod-shaped structure type meet the vertex condition, selecting a Neovius structure if all transition connection nodes of the rod-shaped structure type meet the edge condition, selecting a PRIMITIVE structure if all transition connection nodes of the rod-shaped structure type meet the face center condition, selecting a condition met by one transition connection node as a condition met by all transition connection nodes if all transition connection nodes meet different conditions, and selecting a corresponding TPMS framework structure type;
S3, generating a TPMS lamellar structure and a TPMS framework structure according to the selected TPMS lamellar structure type and the TPMS framework structure type, generating a transition structure of the two structures by utilizing functions of the TPMS lamellar structure and the TPMS framework structure, and bridging the TPMS lamellar structure type and the TPMS framework structure by utilizing the transition structure to obtain an intermediate structure, wherein the intermediate structure comprises the TPMS lamellar structure, the transition structure with unit cell thickness and the TPMS framework structure which is used as a non-transition area which are sequentially connected;
and S4, generating a rod-shaped structure according to the selected rod-shaped structure type, and replacing a non-transition region of the intermediate structure to obtain the TPMS sheet-rod-shaped mixed lattice structure comprising the TPMS sheet structure, the transition structure with unit cell thickness and the rod-shaped structure which are sequentially connected.
2. The TPMS slice and rod mixed lattice structure generation method of claim 1, wherein the rod structure types include SC, BCC, SC-BCC hybrid, NP1, iso truss, rhombic dodecahedron, auxetic, truncated cube, OCT and CC, wherein SC, BCC, SC-BCC hybrid, NP1, iso truss and Rhombic dodecahedron satisfy vertex conditions, auxetic and Truncated cube satisfy edge conditions, OCT and CC satisfy face-centered conditions.
3. The TPMS slice and rod hybrid lattice structure generation method of claim 1, wherein the TPMS slice structure types include a TPMS P slice lattice structure, a TPMS G slice lattice structure, a TPMS D slice lattice structure, and a TPMS I-WP slice lattice structure.
4. The TPMS sheet and rod mixed lattice structure generation method of claim 1, wherein the function of the transition structure is expressed as:
;
Wherein, A function representing a transition structure; Is the first A function of a TPMS lamellar structure or TPMS skeleton structure,,Representing the number of superimposed functions, n=2; Representation of Weight parameters of each TPMS lamellar structure or TPMS skeleton structure control continuous transition among the structures.
5. The method for generating a mixed TPMS sheet and rod lattice structure according to claim 4,Expressed as:
;
;
wherein k represents a constant for controlling the length of the transition section; representation points And the firstA distance function of a laminated structure of each TPMS or a skeleton structure of each TPMS,Representation pointsRepresentation and the firstA distance function of each TPMS lamellar structure or TPMS skeleton structure is used for controlling the boundary of the function; representing the coordinates of point clouds formed by the boundary of the jth TPMS lamellar structure or TPMS skeleton structure; representing the coordinates of the points in space in a cartesian coordinate system.
6. The TPMS sheet and rod mixed lattice structure generation method of claim 1, wherein mathematical expressions of each type of TPMS skeleton structure are as follows:
;
;
;
Wherein, A function representing the framework structure of I-WRAPPED PACKAGE TPMS; a function representing Neoviuse TPMS skeletal structures; a function representing PRIMITIVE TPMS skeletal structures; Representing coordinates of points in space in a Cartesian coordinate system; 、 And Constant parameters controlling the period of the framework structures I-WRAPPED PACKAGE, neovius and PRIMITIVE TPMS are shown respectively.
7. The TPMS sheet and rod mixed lattice structure generating method according to claim 1, further comprising the steps of, after S4:
s5, using additive manufacturing technology to generate the real object with the TPMS sheet and rod-shaped mixed lattice structure.
8. The TPMS sheet and rod-shaped mixed lattice structure comprises a TPMS sheet structure, a transition structure with unit cell thickness and a rod-shaped structure which are sequentially connected, wherein the TPMS sheet structure, the transition structure with unit cell thickness and the rod-shaped structure are generated based on the TPMS sheet and rod-shaped mixed lattice structure generation method according to any one of claims 1-7.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6454811B1 (en) * | 1998-10-12 | 2002-09-24 | Massachusetts Institute Of Technology | Composites for tissue regeneration and methods of manufacture thereof |
| CN112316207A (en) * | 2020-09-15 | 2021-02-05 | 北京科技大学 | Mixed lattice porous gradient scaffold and preparation method thereof |
| CN113821848A (en) * | 2021-11-24 | 2021-12-21 | 武汉科技大学 | An isoparametric transformation hybrid structure of a bionic bone scaffold and its 3D printing method |
| KR20220011399A (en) * | 2020-07-21 | 2022-01-28 | 전남대학교산학협력단 | Fabrication method of 3 dimensional structures of thin shell with triply periodic minimal surfaces without templates |
| CN119830672A (en) * | 2025-01-09 | 2025-04-15 | 西北工业大学 | Volume fraction comprehensive evaluation model of Zener ratio of mixed TPMS structure |
-
2025
- 2025-05-20 CN CN202510647377.4A patent/CN120180530B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6454811B1 (en) * | 1998-10-12 | 2002-09-24 | Massachusetts Institute Of Technology | Composites for tissue regeneration and methods of manufacture thereof |
| KR20220011399A (en) * | 2020-07-21 | 2022-01-28 | 전남대학교산학협력단 | Fabrication method of 3 dimensional structures of thin shell with triply periodic minimal surfaces without templates |
| CN112316207A (en) * | 2020-09-15 | 2021-02-05 | 北京科技大学 | Mixed lattice porous gradient scaffold and preparation method thereof |
| CN113821848A (en) * | 2021-11-24 | 2021-12-21 | 武汉科技大学 | An isoparametric transformation hybrid structure of a bionic bone scaffold and its 3D printing method |
| CN119830672A (en) * | 2025-01-09 | 2025-04-15 | 西北工业大学 | Volume fraction comprehensive evaluation model of Zener ratio of mixed TPMS structure |
Non-Patent Citations (2)
| Title |
|---|
| MARTIN, N ; SEO, S 等: "Reactor physics characterization of triply periodic minimal surface-based nuclear fuel lattices", PROGRESS IN NUCLEAR ENERGY, vol. 165, 4 February 2024 (2024-02-04) * |
| 袁飞泉: "三重周期极小曲面的点阵结构设计与吸能性能分析", 中国优秀硕士学位论文全文数据库-工程科技Ⅰ辑, no. 04, 15 April 2024 (2024-04-15) * |
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