A heterogeneous fusion dot array design method based on interpolation method

Abstract

The application provides a heterogeneous fusion lattice design method based on an interpolation method, and belongs to the technical field of structural lightweight design and structural optimization, and comprises the following steps: S1, constructing two or more types of TPMS lattice structures, and setting independent numbers for each type of lattice unit; S2, calculating the unit space coordinate matrix of the lattice unit; S3, calculating the numbers of the lattice structure units on both sides of the fusion interface according to an implicit discriminant, and obtaining a unit type distribution matrix; S4, constructing an interface interpolation type heterogeneous fusion lattice based on a Voronoi function; S5, obtaining a unit intersection relationship matrix according to the adjacency relationship of each lattice unit; and S6, locally strengthening the fusion interface of the heterogeneous fusion lattice by using a density factor d according to the unit intersection relationship matrix obtained in step S5; the application can guarantee the topological integrity of the transition region connecting units in the fusion of any complex curved surface, and locally strengthen the weak fusion interface, so that a high-rigidity and high-strength heterogeneous fusion lattice is obtained.

Description

Technical Field

[0001] This invention belongs to the field of lightweight structural design and structural optimization technology, specifically involving a heterogeneous fusion lattice design method based on interpolation. Background Technology

[0002] Triple Periodic Minimal Surfaces (TPMS) lattice structures possess numerous superior mechanical properties, including high specific strength, high specific stiffness, high energy absorption, and lightweight. They are also easily designed with parametric, autonomous control, effectively avoiding stress concentration, and are widely used in aerospace, biomedicine, sports equipment, and many other fields. The development of additive manufacturing technology has provided greater design flexibility for TPMS lattices. Heterogeneous fusion lattices can fully leverage the functional advantages of different TPMS lattice configurations, facilitating the integrated material and functional design of lattice structures under service conditions.

[0003] However, the current optimization design of heterogeneous fused lattices faces the following challenges: First, existing methods have poor universality for complex curved surface fusion interfaces, and impurity structures such as incomplete or damaged units are prone to appear at the boundaries; second, there is a lack of methods for controlling the stiffness of weak boundaries, making it difficult to optimize weak stiffness structures such as extremely small rod diameters and large holes that appear when connecting low relative density lattices, which greatly affects the mechanical properties and additive manufacturing process of heterogeneous fused lattices. Summary of the Invention

[0004] The purpose of this invention is to solve the problems mentioned in the background art and provide a heterogeneous fusion lattice design method based on interpolation, which can ensure the topological integrity of the connection units in the transition region of fusion of arbitrarily complex curved surfaces, and locally enhance the weak fusion interface to obtain a heterogeneous fusion lattice with high stiffness and high strength.

[0005] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A heterogeneous fusion lattice design method based on interpolation includes the following steps:

[0007] S1. Construct two or more types of TPMS dot matrix structures and assign independent numbers to the dot matrix units of each type of dot matrix structure.

[0008] S2. Calculate the unit space coordinate matrix of the lattice unit based on the lattice scale and unit size of the lattice structure determined in step S1.

[0009] S3. Calculate the number of the lattice structure units on both sides of the fusion interface based on the implicit discriminant formula to obtain the unit type distribution matrix;

[0010] S4. Construct an interface interpolation heterogeneous fusion lattice based on the Voronoi function-related unit spatial coordinate matrix and unit type distribution matrix.

[0011] S5. Obtain the cell intersection matrix based on the adjacency relationship of each lattice cell;

[0012] S6. Based on the inter-unit intersection matrix obtained in step S5, the density factor d is used to locally enhance the fusion interface of the heterogeneous fusion lattice.

[0013] Preferably, step S1 involves constructing a TPMS lattice structure, including determining the lattice type, lattice size, cell size, and relative density of the lattice structure.

[0014] Preferably, step S2 first calculates the center coordinates of the lattice element using the following formula.

[0015]

[0016] Among them, (x i ,y j ,z k ) represents the center coordinates of the lattice element in the design domain, i, j, and k represent the spatial indices of the current lattice element in the x, y, and z directions, respectively, numx, numy, and numz represent the number of lattice elements in the lattice structure in the x, y, and z directions, respectively, and L represents the element size of the lattice structure.

[0017] Then, the unit space coordinate matrix is ​​calculated using the following formula.

[0018]

[0019] Where ele[(x i ,y j ,z k )] is the coordinate matrix of the unit space.

[0020] Preferably, step S3 includes the following specific processes:

[0021] First, determine the number NO of the lattice elements on both sides of the m-th fusion interface. m Specifically, it is determined by the following formula.

[0022]

[0023] Where, m A and m B NO represents the number of the lattice element on the inner and outer sides of the m-th fusion interface, respectively. m The corresponding specific value, m A m is the number corresponding to the newly fused lattice unit. BThe original lattice element number; f m (x i ,y j ,z k ) is the implicit discriminant of the m-th fusion interface, where m = 1, 2, 3, ...; the order in which the m-th fusion interface is formed is from first to last as the value of m increases. The lattice units on the outside of the m-th fusion interface retain their original numbers, while the numbers of the lattice units on the inside are the numbers corresponding to the newly fused lattice units.

[0024] Then, each element of the cell space coordinate matrix is ​​substituted into all implicit discriminants in turn, satisfying f m (x i ,y j ,z k The maximum value of index m corresponding to ) > 0 m Specific value (m) max ) A The number S of the lattice unit corresponding to this element. i,j,k The unit type distribution matrix is ​​determined by the following formula.

[0025]

[0026] Where T[S i,j,k ] is the unit type distribution matrix.

[0027] Preferably, the heterogeneous fusion lattice expression in step S4 is:

[0028]

[0029] in, The implicit equation of the surface representing the lattice structure is given by n, which is the total number of lattice elements constituting the heterogeneous fused lattice; q is a set constant used to control the transition width of the lattice structure element.

[0030] Preferably, the unit intersection relation matrix in step S5 is I[(u i ,v j ,w k )], where each element u i v j and w k Determined by the following formula

[0031]

[0032]

[0033]

[0034] Among them, S i,j,kThe center coordinates are (x i ,y j ,z k The number of the lattice element, S i+1,j,k S i,j+numx,k and S i,j,k+numx*numy The center coordinates are (x i ,y j ,z k The lattice elements of ) are numbered along the x, y and z directions, respectively, of the adjacent lattice elements.

[0035] Preferably, the density factor d mentioned in step S6 includes density factor components along the x, y, and z directions, respectively. x d y d z Determined by the following formulas respectively

[0036]

[0037]

[0038]

[0039] Where p is a set constant used to adjust the range of influence of the density factor; x intersec y intersec and z intersec These are the mean center coordinates of adjacent lattice elements in the x, y, and z directions, respectively, used to describe the intersection positions between lattice elements;

[0040] The implicit equation of the enhanced lattice structure element is:

[0041]

[0042] in, The implicit equations for the surface of the enhanced lattice structure, The implicit equations for the surface of the lattice structure before enhancement; the values ​​of u, v, and w depend on the element intersection relation matrix.

[0043] The beneficial effects of this invention are:

[0044] 1. This invention assigns type numbers to the lattice units of the TPMS lattice structure, and calculates the unit spatial coordinate matrix ele[(x] based on the lattice size and unit dimensions. i ,y j ,z kBased on the implicit discriminant unit type distribution strategy (that is, determining the corresponding number based on whether the lattice unit is located on the outside or inside of the fusion interface represented by the implicit discriminant), the unit type distribution matrix T[S] is calculated by combining the lattice unit number and the unit space coordinate matrix. i,j,k Next, based on the Voronoi function, the interface of arbitrarily complex curved surfaces is transformed into a planar interpolation interface along the three axes of the Cartesian coordinate system, resulting in a heterogeneous fusion lattice that ensures the topological integrity of the connecting units in the transition region. This achieves heterogeneous fusion of units at the boundary of arbitrarily complex curved surfaces, solves the problem of incomplete or damaged units at the boundary of curved surfaces, and broadens the design freedom of the heterogeneous fusion lattice.

[0045] 2. Based on the heterogeneous fusion lattice obtained by interpolation, the element intersection matrix I[(u,v,w)] is obtained according to the adjacency relationship of each element, and the density factor d is introduced as a local parameter of the TPMS implicit equation to realize the local enhancement of the weak region of the fusion interface, thereby obtaining a heterogeneous fusion lattice with high stiffness and high strength. That is, a stiffness and strength control method for the weak boundary of the heterogeneous fusion lattice is proposed. The density factor is innovatively introduced to realize the precise enhancement of the weak stiffness boundary structure, thereby obtaining a heterogeneous fusion lattice with high stiffness and high strength. This effectively solves the shortcomings of traditional design, such as weak mechanical properties of the fusion interface and poor universality for complex curved surface boundaries. Attached Figure Description

[0046] Figure 1 A diagram illustrating the design process of transforming complex curved surface boundaries into interpolation boundaries;

[0047] Figure 2 This is a flowchart of the present invention;

[0048] Figure 3 This is a schematic diagram illustrating the universality of the interpolation method;

[0049] Figure 4 A schematic diagram illustrating the determination of element intersection relationships and local enhancement of density factor;

[0050] Figure 5 The diagram shows the design results of the spherical fusion lattice after interpolation optimization and the finite element analysis process.

[0051] Figure 6 The image shows the results of the finite element analysis. Detailed Implementation

[0052] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0053] It should be noted that the terms such as "upper", "lower", "left", "right", "front", and "back" used in the invention are only for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0054] like Figure 1-4 As shown, this invention provides a heterogeneous fusion lattice design method based on interpolation, comprising the following steps:

[0055] S1. Construct two or more types of TPMS dot matrix structures and assign independent numbers to the dot matrix units of each type of dot matrix structure.

[0056] The parameters that need to be determined when constructing a TPMS lattice structure include the lattice type, lattice size, element size, and relative density. The implicit equations of the TPMS lattice structure include, but are not limited to, the following types:

[0057] Equation of P-type lattice surface:

[0058] f P (x, y, z)=cosX+cosY+cosZ-0.51(cosXcosY+cosXcosY+cosYcosZ)-t (1)

[0059] Equation of G-type lattice surface:

[0060] f G (x, y) ， z)=sinXcosY+sinYcosZ+sinZcosX-t (2)

[0061] Equation of D-type lattice surface:

[0062] f D (x,,z)==sinXsinYsinZ+sinXcosYcosZ+cosXsinYcosZ+cosXcosYsinZ-t(3)

[0063] IWP type lattice surface equation:

[0064] f IWP (x, y, z)=cosXcosY+cosXcosZ+cosYcosZ-0.51(cos2X+cos2Y+cos2Z)-t(4)

[0065] Where X = 2πx / L, Y = 2πy / L, Z = 2πz / L, L represents the unit size of the lattice structure, the relative density of the lattice structure is controlled by the level set constant t, and x, y, z are the three axial coordinates in the Cartesian coordinate system.

[0066] Assign a number to the lattice unit of each type of lattice structure (the number represents the corresponding lattice structure type). The number includes, but is not limited to, Arabic numerals, English letters and their permutations and combinations. The number of lattice units of each type of TPMS lattice structure is unique. The number of numbers depends on the number of lattice unit types in the heterogeneous fused lattice (that is, the number of TPMS lattice structure types of lattice units in the heterogeneous fused lattice).

[0067] S2. Calculate the unit space coordinate matrix of the lattice unit based on the lattice scale and unit size of the lattice structure determined in step S1.

[0068] The principle of calculating the unit space coordinate matrix of the lattice unit based on the lattice size and unit size is as follows: The TPMS lattice structure is a periodic structure obtained by TPMS lattice unit array. If the center point of the lattice structure is the origin (0, 0, 0), then under a certain lattice size and lattice unit size, the center coordinates of each TPMS lattice unit that makes up the TPMS lattice structure can be calculated. The result of the calculation is the unit space coordinate matrix, and the center coordinates reflect the spatial position of the TPMS lattice unit in the TPMS lattice structure.

[0069] The specific calculation process is as follows:

[0070] First, calculate the center coordinates of the lattice element using the following formula.

[0071]

[0072] Among them, (x i ,y j ,z k ) represents the center coordinates of the lattice element in the design domain, i, j, and k represent the spatial indices of the current lattice element in the x, y, and z directions, respectively (e.g., i represents the i-th lattice element in the x direction of the lattice structure), numx, numy, and numz represent the number of lattice elements in the x, y, and z directions of the lattice structure, respectively (e.g., numx represents the total number of numx lattice elements in the x direction of the lattice structure), and L represents the element size of the lattice structure;

[0073] Then, the unit space coordinate matrix is ​​calculated using the following formula.

[0074]

[0075] Where ele[(x i ,y j ,z k )] is the unit space coordinate matrix, k = 1, 2, 3, ... represents each value of k, ele[(xi ,y j ,z k Each element corresponds to all elements on the right-hand side of the above equation. For example, if k = 2, then ele[(x i ,y j ,z k This includes all elements z on the right-hand side of the above equation. k These correspond to the values ​​of z1 and z2.

[0076] S3. Calculate the number of the lattice structure units on both sides of the fusion interface based on the implicit discriminant formula to obtain the unit type distribution matrix;

[0077] The specific processes include the following:

[0078] First, determine the number NO of the lattice elements on both sides of the m-th fusion interface. m Specifically, it is determined by the following formula.

[0079]

[0080] Where, m A and m B NO represents the number of the lattice element on the inner and outer sides of the m-th fusion interface, respectively. m The corresponding specific value, m A m is the number corresponding to the newly fused lattice unit. B The numbers correspond to the original lattice units; that is, the lattice unit numbers inside the fusion interface are the numbers corresponding to the newly fused lattice units, while the lattice units outside the fusion interface retain their original numbers. A The value of m is unique, but B The value may not be unique, for example, in cases where the merged interfaces overlap (this will be explained in detail later); f m (x i ,y j ,z k ) represents the implicit discriminant of the m-th fusion interface (the implicit expression of the fusion interface can be any complex surface in three-dimensional space), f m (x i ,y j ,z k ) > 0 indicates that the center coordinates are (x i ,y j ,z k The lattice units of f are located inside the fusion interface. m (x i ,y j ,z k )≤0 means the center coordinates are (x i ,y j ,z kThe lattice elements are located on or outside the fusion interface; m = 1, 2, 3, ...;

[0081] The order in which the m-th fusion interface is formed is from first to last as the value of m increases. The lattice units on the outer side of the m-th fusion interface retain their original numbers, while the numbers of the lattice units on the inner side are the numbers corresponding to the newly fused lattice units.

[0082] For example, there are 3 fusion interfaces. The first fusion interface is formed by the fusion of different lattice structures. The fusion interface formed by the fusion of the first different lattice structures is then fused with another lattice structure (this lattice structure can be any lattice structure, either of the two lattice structures fused in the first fusion, or it can be a new lattice structure) to form the second fusion interface. The third fusion interface is formed by the fusion interface formed after the second fusion being fused with another lattice structure (again, this lattice structure can be any lattice structure, either the same as the previous one or a completely new lattice structure). If there are more fusion interfaces, the formation process is repeated in this way. The lattice structures that have already participated in the fusion can participate in the fusion again in subsequent fusions.

[0083] It is important to note that when there are overlapping interfaces, the lattice units inside the final fused interface are numbered according to the number of the most recently fused lattice structure, while the lattice units outside the fused interface retain their original numbers. For example, the lattice units inside and outside the first fused interface are numbered 1 and 2 respectively. A and 1 B The second fusion interface intersects with the first fusion interface (the two planes intersect, but are not independent). The new lattice structure for the second fusion is numbered 2. A Then the inner side of the second fusion interface is numbered 1. A and 1 B All the dot matrix units were covered by the number 2 A The new lattice units are replaced, but the lattice units on the outer side of the second fusion interface remain unchanged, retaining the original number 1. A and 1 B That is, 2 B =1 A Or 1 B Specifically, the location of the region outside the second fusion interface is determined based on whether it is inside or outside the first fusion interface. B The value; when there are multiple fusion interfaces that intersect, the same principle applies, that is, the dot matrix unit number on the inner side of the final fusion interface is replaced with the number corresponding to the newly fused dot matrix unit, while the dot matrix unit on the outer side of the fusion interface remains unchanged, and the number of its corresponding dot matrix unit also remains unchanged.

[0084] Then, each element of the cell space coordinate matrix is ​​substituted into all implicit discriminants in turn, satisfying f m (x i ,y j ,z k The maximum value of index m corresponding to ) > 0 m Specific value (m) max ) A The number S of the lattice unit corresponding to this element. i,j,k ;

[0085] For example, substituting the center coordinates of a certain lattice element into the implicit discriminant with m taking values ​​from 1 to 4, we obtain the following results:

[0086] f1(x i ,y j ,z k )>0

[0087] f2(x i ,y j ,z k )>0

[0088] f3(x i ,y j ,z k ) < 0

[0089] f4(x i ,y j ,z k ) < 0

[0090] Then, the number S of this lattice element i,j,k The value is 2 A ;

[0091] The unit type distribution matrix is ​​determined by the following formula.

[0092]

[0093] Where T[S i,j,k ] is the unit type distribution matrix.

[0094] S4. Construct an interface interpolation heterogeneous fusion lattice based on the Voronoi function-related unit spatial coordinate matrix and unit type distribution matrix.

[0095] The heterogeneous fusion lattice expression is as follows:

[0096]

[0097] in, The implicit equations of the surface representing the lattice structure, and the lattice element types in the heterogeneous fused lattice structure are determined by the element type distribution matrix T[S]i,j,k The determination is made through the unit type distribution matrix T[S]. i,j,k The type (or number) of the lattice element at each location is determined, and the position of the lattice element is related to the element space coordinate matrix ele[(x i ,y j ,z k [Related; n is the total number of lattice units constituting the heterogeneous fusion lattice; q is a set constant used to control the transition width of the lattice structure unit.]

[0098] S5. Obtain the cell intersection matrix based on the adjacency relationship of each lattice cell;

[0099] The intersecting relationship matrix of the units is I[(u i ,v j ,w k )], where each element u i v j and w k Determined by the following formula

[0100]

[0101]

[0102]

[0103] Among them, S i,j,k The center coordinates are (x i ,y j ,z k The number of the lattice element, S i+1,j,k S i,j+numx,k and S i,j,k+numx*numy The center coordinates are (x i ,y j ,z k The lattice elements of ) are numbered along the x, y and z directions, respectively, of the adjacent lattice elements.

[0104] S6. Based on the inter-unit intersection matrix obtained in step S5, the density factor d is used to locally enhance the fusion interface of the heterogeneous fusion lattice.

[0105] The density factor d includes density factor components along the x, y, and z directions, respectively. x d y d z Determined by the following formulas respectively

[0106]

[0107]

[0108]

[0109] Where p is a set constant used to adjust the range of influence of the density factor; x intersec y intersec and z intersec These are the mean center coordinates of adjacent lattice elements in the x, y, and z directions, respectively, used to describe the intersection positions between lattice elements;

[0110] The implicit equation of the enhanced lattice structure element is:

[0111]

[0112] in, The implicit equations for the surface of the enhanced lattice structure, The implicit equations for the surface of the lattice structure before enhancement; the values ​​of u, v, and w depend on the element intersection relation matrix.

[0113] To better illustrate the implementation process of this invention, an embodiment with specific parameters is provided below for further explanation:

[0114] The present invention will be illustrated below using the optimization of spherical heterogeneous fusion lattice as an example.

[0115] S1-S4: First, assign numbers to the four types of TPMS lattice units, with P-type lattice units numbered 0, IWP-type lattice units numbered 1, G-type lattice units numbered 2, and D-type lattice units numbered 3; set the unit size to 10mm×10mm×10mm, the lattice size to 6×6×6, and the relative density to 25%.

[0116] Next, the element spatial coordinate matrix ele[(x] is calculated based on the lattice size and element size. i ,y j ,z k )).

[0117] Then set the implicit discriminant of the merged interface as follows:

[0118] f(x, y, z) = 10 2 -(x2+y 2 +z 2 )

[0119] Where x, y, and z are the three axial coordinates in the Cartesian coordinate system.

[0120] The unit type distribution strategy based on implicit discriminative methods (i.e., step S3) is used to calculate the lattice unit numbers on both sides of the fusion interface, thereby obtaining the unit type distribution matrix T[S]. i,j,k ].

[0121] Finally, based on the Voronoi function, the spatial coordinate matrix of the associated unit is ele[(x i ,y j ,z k )] and unit type distribution matrix T[S i,j,k A spherical interface interpolation heterogeneous fusion lattice is constructed, with the q-value in the Voronoi function set to 0.2. The design process is as follows: Figure 1 As shown, Figure 3 This invention demonstrates its universality in interpolation design for complex curved surface boundaries.

[0122] S5-S6: Calculate and determine the cell intersection matrix I[(u] based on the adjacency relationship of each cell. i ,v j ,w k )).

[0123] Next, C is set to 2.5 and p to 1. The density factor d is calculated and incorporated into the implicit equations of the TPMS lattice surface to achieve local reinforcement of the heterogeneous fusion boundary, resulting in a high-stiffness and high-strength heterogeneous fusion lattice. The design process is as follows: Figure 4 As shown, dp represents the enhancement effect of density factor d on P-type TPMS lattice elements, and dG represents the enhancement effect of density factor d on G-type TPMS lattice elements.

[0124] S7: Conduct finite element analysis to verify the optimized heterogeneous fusion lattice; finite element analysis tools include, but are not limited to, various CAE software. The verification method is to use a pressure plate to perform quasi-static compression on the lattice, test the stiffness and strength of the lattice, and compare it with the same heterogeneous fusion lattice obtained by traditional methods.

[0125] The material used in the finite element analysis of this embodiment has an elastic modulus E of 1328.99 MPa, a Poisson's ratio υ of 0.39, and a density ρ of 1.179e-9 g / mm³. 3 The bottom of the structure is completely fixed, and the vertical downward displacement load F = 24 mm is applied to the top pressure plate. The interpolated optimized spherical fusion lattice design results and the finite element analysis process are as follows: Figure 5 As shown.

[0126] S8: Outputs the high-stiffness, high-strength heterogeneous fused lattice structure verified by the finite element analysis in S7. The finite element analysis results are as follows: Figure 6 As shown, the heterogeneous fused lattice obtained based on the interpolation method proposed in this invention has a higher specific stiffness (by more than 20%) and a higher specific strength (by more than 10%) compared to traditional methods.

[0127] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A heterogeneous fusion lattice design method based on interpolation, characterized in that, Includes the following steps: S1. Construct two or more types of TPMS dot matrix structures and assign independent numbers to the dot matrix units of each type of dot matrix structure. S2. Calculate the unit space coordinate matrix of the lattice unit based on the lattice scale and unit size of the lattice structure determined in step S1. S3. Calculate the element numbers of the lattice structure units on both sides of the fusion interface based on the implicit equations of the surface, and obtain the element type distribution matrix; specifically including: First, determine the numbering of the lattice elements on both sides of the m-th fusion interface. Specifically, it is determined by the following formula: in, and These represent the numbers of the lattice elements on the inner and outer sides of the m-th fusion interface, respectively. The corresponding specific value, The corresponding number for the newly fused lattice unit. The original lattice unit number; Let m be the implicit equation of the m-th fusion interface, where m = 1, 2, 3, ...; the order in which the m-th fusion interface is formed is from smallest to largest, in ascending order; the lattice elements on the outer side of the m-th fusion interface retain their original numbers, while the numbers of the lattice elements on the inner side are the numbers corresponding to the newly fused lattice elements; then, each element of the element space coordinate matrix is ​​substituted into all the implicit equations of the surface, satisfying... The maximum value corresponding to the subscript m Specific value The number of the lattice unit corresponding to this element. The unit type distribution matrix is ​​determined by the following formula: in This is the cell type distribution matrix; S4. Based on the Voronoi function-correlated element spatial coordinate matrix and element type distribution matrix, construct an interface interpolation-type heterogeneous fusion lattice; wherein, the expression of the heterogeneous fusion lattice is: in, The implicit equation of the surface representing the lattice structure, where n is the total number of lattice elements constituting the heterogeneous fused lattice; and q is a set constant used to control the transition width between lattice structure elements. S5. Obtain the element intersection matrix based on the adjacency relationship of each lattice element; wherein, the element intersection matrix is... Each of its elements Determined by the following formula: in, Indicates the center coordinates as The numbering of the lattice elements, , and Indicates the center coordinates as The lattice elements are respectively along The numbers of the lattice elements adjacent in three directions; S6. Based on the element intersection relation matrix obtained in step S5, the fusion interface of the heterogeneous fusion lattice is locally enhanced using a density factor d; wherein, the density factor d includes along... The density factor components in the three directions are respectively , , They are determined by the following formulas respectively: Where p is a defined constant; , and These are the mean values ​​of the center coordinates of adjacent lattice elements in the x, y, and z directions, respectively; The implicit equation of the enhanced lattice structure element is: in, The implicit equations for the surface of the enhanced lattice structure, The implicit equations of the surface of the lattice structure before enhancement; , and The value depends on the inter-cell intersection matrix.

2. The heterogeneous fusion lattice design method based on interpolation according to claim 1, characterized in that: Step S1 involves constructing the TPMS lattice structure, including determining the lattice type, lattice size, cell size, and relative density of the lattice structure.

3. The heterogeneous fusion lattice design method based on interpolation according to claim 1, characterized in that: Step S2 first calculates the center coordinates of the lattice element using the following formula. in, These are the center coordinates of the lattice elements in the design domain. These respectively represent the current lattice elements in Spatial indexes in three directions, They respectively represent the lattice structure in The number of lattice elements in the direction, where L represents the element size of the lattice structure; Then, the unit space coordinate matrix is ​​calculated using the following formula. in is the coordinate matrix of the cell space.

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