Design method and system of multistage energy regulation type metamaterial

Abstract

The invention discloses a design method and system of a multistage energy regulation type metamaterial. The method comprises the following steps: constructing two types of three-period minimal curved surface unit cells by using an isosurface extraction method; mixing the constructed two types of three-period minimal curved surface unit cells to obtain a third type of three-period minimal curved surface unit cells; respectively arraying the three types of three-period minimum curved surface unit cells to obtain three types of three-period minimum curved surface three-dimensional lattice structures; using a Sigmoid function to mix and superpose the three types of three-period minimal curved surface three-dimensional lattice structures to obtain a mixed lattice structure model; on the basis of human spine mechanical characteristics, Boolean subtraction is used for carrying out wall thickness changing operation on the mixed lattice structure model, a compression mechanical property test is carried out to obtain a mixed lattice structure design model in an optimal gradient curved surface offset mode, and the multi-stage energy regulation and control metamaterial is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of vibration-damping and energy-absorbing superconducting materials, and in particular relates to a design method and system for a multi-level energy-regulating metamaterial. Background Art

[0002] Metamaterials have the ability to achieve unconventional physical properties by designing microstructures. Combined with the geometric characteristics of TPMS structures, they can further enhance the performance of energy-absorbing materials. Three-periodic minimal surface structures have significant advantages in porosity, lightweight design and mechanical properties: by changing the size or geometric parameters of the unit cell, the size, shape and distribution of the pores can be precisely controlled, and the porosity can be optimized to achieve lightweight structures while maintaining excellent stiffness and strength. At the same time, with the unique functions of metamaterials, such as the negative Poisson's ratio effect or gradient performance design, the vibration reduction and energy absorption effect and the controllability of the energy transfer path can be further improved. Combining the advantages of metamaterials and three-periodic minimal surface structures can not only achieve efficient energy absorption and vibration reduction, but also give the material additional functionality, such as dynamic response regulation, adaptive performance, etc., to expand its application scenarios in industrial and civilian fields, and provide a new direction for the design of high-performance vibration reduction and energy absorption materials in the future. Summary of the invention

[0003] The present invention aims to solve the deficiencies of the prior art and provides the following solutions:

[0004] A method for designing a multi-level energy-regulating metamaterial comprises the following steps:

[0005] The first three-periodic minimal surface unit cell and the second three-periodic minimal surface unit cell are constructed by using the isosurface extraction method;

[0006] Mixing the first three-period minimal surface unit cell and the second three-period minimal surface unit cell to obtain a third three-period minimal surface unit cell;

[0007] Arrange the first three-period minimal surface unit cell, the second three-period minimal surface unit cell and the third three-period minimal surface unit cell respectively to obtain a first three-period minimal surface three-dimensional lattice structure, a second three-period minimal surface three-dimensional lattice structure and a third three-period minimal surface three-dimensional lattice structure;

[0008] The first three-period minimal surface three-dimensional lattice structure, the second three-period minimal surface three-dimensional lattice structure and the third three-period minimal surface three-dimensional lattice structure are mixed and superimposed by using a Sigmoid function to obtain a mixed lattice structure model;

[0009] Based on the mechanical properties of the human spine, the hybrid lattice structure model is subjected to a variable wall thickness operation using a Boolean subtraction operation, and a compression mechanical property test is performed to obtain the hybrid lattice structure design model with the optimal gradient surface offset mode, thereby obtaining the multi-level energy regulation metamaterial.

[0010] Preferably, the method for constructing the first three-period minimal surface unit cell and the second three-period minimal surface unit cell comprises: generating the first three-period minimal surface unit cell and the second three-period minimal surface unit cell based on different implicit function expressions, wherein the implicit function expressions comprise:

[0011]

[0012] in, represents the first three-periodic minimal surface unit cell, represents the second three-periodic minimal surface unit cell, l represents the length of the representative cell of the three-periodic minimal surface structure in the x, y and z directions, and t represents the implicit function control term parameter.

[0013] Preferably, the method for obtaining the third three-period minimal surface unit cell comprises: performing a mixed design on the two implicit function expressions to obtain the third three-period minimal surface unit cell, and the implicit function expression of the third three-period minimal surface unit cell is:

[0014]

[0015] in, represents the third three-periodic minimal surface unit cell, and A represents the structure factor of the original three-periodic minimal surface structure.

[0016] Preferably, the Sigmoid function is:

[0017]

[0018] Among them, k represents the transition width of the mixed lattice, and G(x, y, z) represents the set of spatial coordinates of the shape transformation of different regions.

[0019] Preferably, the method for performing the variable wall thickness operation includes:

[0020]

[0021] Among them, t(δ) represents the variable wall thickness function, D and B represent constants, δ represents the length from the spatial point to the starting point in the direction of density gradient, T represents the period, and α represents the phase.

[0022] Preferably, the method for performing the variable wall thickness operation further comprises:

[0023]

[0024] Among them, t(δ) represents the variable wall thickness function, a0 represents the adjustment parameter of the wall thickness fluctuation reference value, k represents the order of the Fourier series, and a k represents the k-order cosine component, b k represents the k-order sinusoidal component, and ζ represents the longitudinal position along the loading direction of the structure.

[0025] The present invention also provides a design system for multi-level energy-regulating metamaterials, the system applying any of the above methods, including: a unit cell building module, a unit cell mixing module, an array module, a lattice mixing module and an optimization module;

[0026] The unit cell construction module constructs a first three-period minimal surface unit cell and a second three-period minimal surface unit cell by using an isosurface extraction method;

[0027] The unit cell mixing module mixes the first three-period minimal surface unit cell and the second three-period minimal surface unit cell to obtain a third three-period minimal surface unit cell;

[0028] The array module arrays the first three-period minimal surface unit cell, the second three-period minimal surface unit cell and the third three-period minimal surface unit cell respectively to obtain a first three-period minimal surface three-dimensional lattice structure, a second three-period minimal surface three-dimensional lattice structure and a third three-period minimal surface three-dimensional lattice structure;

[0029] The lattice mixing module uses a Sigmoid function to mix and superimpose the first three-period minimal surface three-dimensional lattice structure, the second three-period minimal surface three-dimensional lattice structure and the third three-period minimal surface three-dimensional lattice structure to obtain a mixed lattice structure model;

[0030] The optimization module uses Boolean subtraction operations to perform variable wall thickness operations on the hybrid lattice structure model based on the mechanical properties of the human spine, and performs compression mechanical performance tests to obtain the hybrid lattice structure design model with the optimal gradient surface offset mode, thereby obtaining the multi-level energy regulation metamaterial.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention constructs a three-dimensional lattice structure by mixing different types of three-periodic minimal surface structures, combining metamaterial design concepts and bionic design, and drawing on the mechanical properties of the human spine. The introduction of metamaterials enables the lattice structure to further possess the characteristics of dynamic response regulation and multifunctional energy absorption on the basis of traditional geometric design. Through mechanical property testing, it is verified that this three-dimensional lattice structure combined with the characteristics of metamaterials can achieve multi-level deformation and multi-level energy absorption in a gradient manner, showing significant energy absorption characteristics. In addition, metamaterials give the structure a higher degree of design freedom, enabling it to exhibit excellent impact resistance in complex environments, while ensuring a balance between structural lightweight and strength, providing a new solution for the further development of high-performance vibration reduction and energy absorption technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0034] Figure 1 A schematic diagram of a method flow chart of an embodiment of the present invention;

[0035] Figure 2 A three-periodic minimal surface unit cell structure according to an embodiment of the present invention, wherein a is a P-type unit cell structure, b is an IWP-type unit cell structure, and c is an HS-type unit cell structure;

[0036] Figure 3 This is a schematic diagram of the HS type three-periodic minimal surface unit cell hybrid design according to an embodiment of the present invention;

[0037] Figure 4 It is a three-periodic minimal surface three-dimensional lattice structure of an embodiment of the present invention, wherein a is a P-type unit cell lattice structure, b is an IWP-type unit cell lattice structure, and c is an HS-type unit cell lattice structure;

[0038] Figure 5 A hybrid lattice structure model according to an embodiment of the present invention;

[0039] Figure 6 It is a schematic diagram of using Fourier series to fit a step function to realize the wall thickness fluctuation of a TPMS structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Embodiment 1

[0043] In this embodiment, if Figure 1 As shown, a design method of a multi-level energy-regulating metamaterial comprises the following steps:

[0044] S1. Construct the first three-periodic minimal surface unit cell and the second three-periodic minimal surface unit cell using the isosurface extraction method.

[0045] The method for constructing the first three-period minimal surface unit cell and the second three-period minimal surface unit cell comprises: generating the first three-period minimal surface unit cell and the second three-period minimal surface unit cell based on different implicit function expressions, the structure of which is as follows: Figure 2 As shown in a and b in the figure, the implicit function expression includes:

[0046]

[0047] in, represents the first three-periodic minimal surface unit cell, represents the second three-periodic minimal surface unit cell, l represents the length of the representative cell of the three-periodic minimal surface structure in the x, y and z directions, and t represents the implicit function control term parameter.

[0048] S2. Mix the first three-period minimal surface unit cell and the second three-period minimal surface unit cell to obtain a third three-period minimal surface unit cell.

[0049] The method for obtaining the third three-periodic minimal surface unit cell includes: mixing the above two implicit function expressions to generate the third three-periodic minimal surface unit cell with a unique topological form, the structure is as follows Figure 2 As shown in c, its implicit function expression is:

[0050]

[0051] in, represents the third three-periodic minimal surface unit cell, A represents the structure factor of the original three-periodic minimal surface structure, 0<A<1. The design principle of this structure is as follows Figure 3 as shown

[0052] S3. Array the first three - period minimal - surface unit cell, the second three - period minimal - surface unit cell, and the third three - period minimal - surface unit cell respectively to obtain a first three - period minimal - surface three - dimensional lattice structure, a second three - period minimal - surface three - dimensional lattice structure, and a third three - period minimal - surface three - dimensional lattice structure.

[0053] In this embodiment, the three three - period minimal - surface unit cells are respectively arrayed along the x, y, and z directions to form three three - period minimal - surface three - dimensional lattice structures, as Figure 4 shown, where a is the P - type unit - cell lattice structure, b is the IWP - type unit - cell lattice structure, and c is the HS - type unit - cell lattice structure.

[0054] S4. Use the Sigmoid function to mix and superpose the first three - period minimal - surface three - dimensional lattice structure, the second three - period minimal - surface three - dimensional lattice structure, and the third three - period minimal - surface three - dimensional lattice structure to obtain a mixed lattice structure model, as Figure 5 shown.

[0055] In this embodiment, the Sigmoid function is:

[0056]

[0057] where k represents the transition width of the mixed lattice. The smaller the value of k, the wider the transition region and the smoother the transition; G(x, y, z) represents the set of spatial coordinates for the shape transformation of different regions and can be any function of x, y, and z.

[0058] S5. Based on the mechanical properties of the human spine, use the Boolean subtraction operation to perform variable - wall - thickness operations on the mixed lattice structure model, and conduct compression mechanical property tests to obtain a mixed lattice structure design model with the optimal gradient - surface offset method, thereby obtaining a multi - level energy - regulating metamaterial.

[0059] In this embodiment, considering the constraints of the additive manufacturing process, the minimum wall thickness of the variable - wall - thickness model should not be less than the minimum wall thickness that can be formed by existing additive manufacturing equipment. The functional expression for performing the variable - wall - thickness operation is:

[0060]

[0061] where t(δ) represents the variable - wall - thickness function, D and B represent constants, δ represents the length of the spatial point from the starting point in the direction of density gradient, 0 < δ < L, L represents the length of the design domain in the direction of density gradient, T represents the period, controlling the width of the wall - thickness fluctuation, and α represents the phase, adjusting the starting position of the fluctuation.

[0062] In this embodiment, the wall thickness can be more accurately controlled by using the Fourier series fitting function, because the Fourier series can describe complex fluctuation forms and provide a flexible control method for the TPMS structure wall thickness design. The general formula of the Fourier series is:

[0063]

[0064] Parameter a0 can be used to adjust the baseline value of wall thickness fluctuation and determine the center point of wall thickness fluctuation. Parameter k represents the order of Fourier series; the higher the order, the higher the fitting accuracy. Coefficient a k and b k They correspond to the cosine and sine components of the kth order, respectively, and can be adjusted to achieve a specific wall thickness distribution. The parameter ζ represents the longitudinal position along the structural loading direction. The function t(ζ) represents the wall thickness at the corresponding longitudinal position ζ along the structural loading direction. Taking the Fourier series fitting step function as an example, the wall thickness fluctuation form is a step function of 0.7-0.3-0.5, that is, the wall thickness is set to 0.7mm in the P-type area, 0.3mm in the I-type area, and 0.5mm in the HS-type area. Use 3rd, 5th and 10th-order Fourier series for fitting, and the expansion is as follows:

[0065]

[0066] The schematic diagram of using Fourier series fitting step function to realize the wall thickness fluctuation of TPMS structure is as follows Figure 6 shown.

[0067] Based on trigonometric functions, multiple gradient surface offset lattice structure models with the same relative density were created. A three-periodic minimal surface lattice structure was prepared using 316L stainless steel material and compression mechanical properties tests were carried out. The displacement load curves of each model were generated. By comparing the maximum bearing capacity of each model, the lattice structure design model with the optimal gradient surface offset mode with the largest bearing capacity was obtained, which is the optimized designed multi-level energy regulation metamaterial.

[0068] Embodiment 2

[0069] In this embodiment, a design system for a multi-level energy-regulating metamaterial includes: a unit cell building module, a unit cell mixing module, an array module, a lattice mixing module, and an optimization module.

[0070] The unit cell construction module uses the isosurface extraction method to construct the first three-period minimal surface unit cell and the second three-period minimal surface unit cell; the unit cell mixing module mixes the first three-period minimal surface unit cell and the second three-period minimal surface unit cell to obtain the third three-period minimal surface unit cell; the array module arrays the first three-period minimal surface unit cell, the second three-period minimal surface unit cell and the third three-period minimal surface unit cell respectively to obtain the first three-period minimal surface three-dimensional lattice structure, the second three-period minimal surface three-dimensional lattice structure and the third three-period minimal surface three-dimensional lattice structure. Surface three-dimensional lattice structure; the lattice mixing module uses the Sigmoid function to mix and superimpose the first three-period minimal surface three-dimensional lattice structure, the second three-period minimal surface three-dimensional lattice structure and the third three-period minimal surface three-dimensional lattice structure to obtain a mixed lattice structure model; based on the mechanical properties of the human spine, the optimization module uses Boolean subtraction operations to perform variable wall thickness operations on the mixed lattice structure model, and conducts compression mechanical performance tests to obtain the mixed lattice structure design model with the optimal gradient surface offset method, thereby obtaining a multi-level energy regulation metamaterial.

[0071] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A design method for a multi-level energy-regulating metamaterial, characterized in that: The following steps are involved: The first three-periodic minimal surface unit cell and the second three-periodic minimal surface unit cell are constructed by using the isosurface extraction method; Mixing the first three-period minimal surface unit cell and the second three-period minimal surface unit cell to obtain a third three-period minimal surface unit cell; Arrange the first three-period minimal surface unit cell, the second three-period minimal surface unit cell and the third three-period minimal surface unit cell respectively to obtain a first three-period minimal surface three-dimensional lattice structure, a second three-period minimal surface three-dimensional lattice structure and a third three-period minimal surface three-dimensional lattice structure; The first three-period minimal surface three-dimensional lattice structure, the second three-period minimal surface three-dimensional lattice structure and the third three-period minimal surface three-dimensional lattice structure are mixed and superimposed by using a Sigmoid function to obtain a mixed lattice structure model; Based on the mechanical properties of the human spine, the hybrid lattice structure model is subjected to a variable wall thickness operation using a Boolean subtraction operation, and a compression mechanical property test is performed to obtain the hybrid lattice structure design model with the optimal gradient surface offset mode, thereby obtaining the multi-level energy regulation metamaterial.

2. The design method of a multi-level energy-regulating metamaterial according to claim 1, characterized in that: The method for constructing the first three-period minimal surface unit cell and the second three-period minimal surface unit cell comprises: generating the first three-period minimal surface unit cell and the second three-period minimal surface unit cell based on different implicit function expressions, wherein the implicit function expressions comprise: in, represents the first three-periodic minimal surface unit cell, represents the second three-periodic minimal surface unit cell, l represents the length of the representative cell of the three-periodic minimal surface structure in the x, y and z directions, and t represents the implicit function control term parameter.

3. The design method of a multi-level energy-regulating metamaterial according to claim 2, characterized in that: The method for obtaining the third three-period minimal surface unit cell includes: performing a mixed design on the two implicit function expressions to obtain the third three-period minimal surface unit cell, and the implicit function expression of the third three-period minimal surface unit cell is: in, represents the third three-periodic minimal surface unit cell, and A represents the structure factor of the original three-periodic minimal surface structure.

4. The design method of a multi-level energy-regulating metamaterial according to claim 2, characterized in that: The Sigmoid function is: Among them, k represents the transition width of the mixed lattice, and G(x, y, z) represents the set of spatial coordinates of the shape transformation of different regions.

5. The design method of a multi-level energy-regulating metamaterial according to claim 2, characterized in that: The method for performing the variable wall thickness operation includes: Among them, t(δ) represents the variable wall thickness function, D and B represent constants, δ represents the length from the spatial point in the density gradient direction to the starting point, T represents the period, and α represents the phase.

6. The design method of a multi-level energy-regulating metamaterial according to claim 5, characterized in that: The method for performing the variable wall thickness operation also includes: Among them, t(δ) represents the variable wall thickness function, a0 represents the adjustment parameter of the wall thickness fluctuation reference value, k represents the order of the Fourier series, and a k represents the k-order cosine component, b k represents the k-order sinusoidal component, and ζ represents the longitudinal position along the loading direction of the structure.

7. A design system for multi-level energy-regulating metamaterials, the system applying the method according to any one of claims 1 to 6, characterized in that: include: Unit cell building module, unit cell mixing module, array module, lattice mixing module and optimization module; The unit cell construction module constructs a first three-period minimal surface unit cell and a second three-period minimal surface unit cell by using an isosurface extraction method; The unit cell mixing module mixes the first three-period minimal surface unit cell and the second three-period minimal surface unit cell to obtain a third three-period minimal surface unit cell; The array module arrays the first three-period minimal surface unit cell, the second three-period minimal surface unit cell and the third three-period minimal surface unit cell respectively to obtain a first three-period minimal surface three-dimensional lattice structure, a second three-period minimal surface three-dimensional lattice structure and a third three-period minimal surface three-dimensional lattice structure; The lattice mixing module uses a Sigmoid function to mix and superimpose the first three-period minimal surface three-dimensional lattice structure, the second three-period minimal surface three-dimensional lattice structure and the third three-period minimal surface three-dimensional lattice structure to obtain a mixed lattice structure model; The optimization module uses Boolean subtraction operations to perform variable wall thickness operations on the hybrid lattice structure model based on the mechanical properties of the human spine, and performs compression mechanical performance tests to obtain the hybrid lattice structure design model with the optimal gradient surface offset mode, thereby obtaining the multi-level energy regulation metamaterial.

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