A design method of extremely light high-strength damage-resistant dot matrix structure

Abstract

The application relates to the field of structural lightweight design, in particular to a design method of an extremely light high-strength damage-resistant lattice structure, which comprises lattice structure classification and division, simulation analysis and lattice structure thickness optimization, is divided according to whether the directional vectors of each rod of the lattice structure are parallel, whether the included angles between the directional vectors and the load vectors are equal or complementary, and based on the rod thicknesses of different base rods and reinforcing rods, corresponding series design schemes are formulated for the obtained rod types, grid CAE analysis is carried out on the design schemes to obtain stress-strain curves, the yield strengths under the design schemes of different rod types are obtained, the promotion limit factor of the relative yield strength is calculated, the optimal lattice structure thickness optimization scheme is obtained by using the promotion limit factor of the relative yield strength, and finally the thickness and length distribution of the lattice structure are obtained.

Description

Technical Field

[0001] This invention relates to the field of lightweight structural design, specifically to a design method for an extremely lightweight, high-strength, and damage-resistant lattice structure. Background Technology

[0002] Lattice structures, due to their high load-bearing efficiency and superior resistance to explosions and impacts, have excellent application prospects in fields such as mechanics, electromagnetics, acoustics, and thermodynamics, and are now widely used in major defense and industrial sectors such as aerospace, aviation, weaponry, nuclear industry, biomedicine, and vehicles. Currently, there are two main types of lattice structures: 1) spatial truss structures composed of arranged rod units; and 2) spatial surface structures composed of curved surface feature units connected according to specific mapping relationships. Their dimensional design variables include the length, width, and height of the cell, rod or wall thickness, and characteristic angles. Since lattice structures primarily bear axial loads, their reinforcement mainly involves distributing material to localized discrete elements to improve the structure's strength and load-bearing efficiency. There are three main approaches to improving the strength and load-bearing efficiency of lattice structures from a design perspective: 1) Selecting appropriate materials for the lattice structure, such as steel, aluminum, and composite materials; 2) Increasing the thickness of the cells uniformly to improve the strength of the lattice structure; 3) Reducing the thickness of the cells using gradient / variable density to improve the load-bearing efficiency of the lattice structure; 4) Changing the configuration of the lattice structure, such as FCC structures, BCC structures, deformable structures combining FCC and BCC, as well as concave hexagonal structures and taut structures with negative Poisson's ratio effects.

[0003] Furthermore, the design schemes for lattice structures mainly originate from two sources: 1) the atomic spatial arrangement rules and their deformable combinations based on materials metallurgy; and 2) biomimetic design. Building upon these foundations, numerous researchers have matched geometric configurations with their load-bearing mechanisms and explored high-performance structures / equipment at different scales to meet the rigid requirements of integrated design for next-generation structural materials. Therefore, lattice structure design rules have highly focused on the comprehensive system design of shape, size, hierarchical structure, and material integration to match the design intentions of different industries and maximize their overall performance.

[0004] Currently, the mechanical performance limit of lattice structures is δ / δ s ~(ρ / ρ s ) n or E / E s ~(E / E) s ) nThe theoretical limit of n is 1. Designers typically employ various lattice structure configurations across multiple scales to reduce the value of n, but the reduction is limited. Furthermore, due to limitations in 3D or 4D printing capabilities, and considering factors such as manufacturing difficulty, precision, efficiency, and cost, industrial applications generally utilize simple, easily manufactured lattice structures. Complex lattice structures with superior mechanical properties remain only in small-batch laboratory production. Therefore, achieving performance comparable to high-performance complex-shaped structural components from simple lattice structures, and further expanding the performance limits of high-performance complex-shaped structural components, is crucial for resolving the contradiction between the application potential and excellent mechanical properties of lattice structures, the difficulty in approaching the theoretical limit, and for efficiently, effectively, and with high performance, obtaining the ultimate lattice structures for different application scenarios. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an extremely lightweight, high-strength, and damage-resistant lattice structure and its design method. To overcome the deficiencies of the prior art, this invention adopts the following technical solution:

[0006] A design method for ultra-lightweight, high-strength, and damage-resistant lattice structures includes lattice structure classification, simulation analysis, and optimal lattice structure thickness.

[0007] Step 1: Classification of the lattice structure; The structure is classified based on whether the direction vectors of each member are parallel, by extracting the direction vectors of all members. Choose any two members from the list.

[0008] If a m1 / a n1 =a m2 / a n2 =a m3 / a n3 If this is not true, then the two members belong to different types of members;

[0009] If a m1 / a n1 =a m2 / a n2 =a m3 / a n3 Based on this, the direction vector of the member is then calculated. With load vector The included angle θ i If the included angle θ between any two rods i If the two members are equal or complementary, they are classified as members of the same type; otherwise, they are classified as members of different types. For members of the same type, their thickness parameters are consistent.

[0010] Based on the obtained bar type Si Develop corresponding series of design schemes D ijl ;

[0011] Let the member type S i For reinforcement, the remaining member types S k (1≤k≤m, k≠i) represents the base rod, where 1≤i≤m, m is the number of rod types, and the thickness d of the reinforcing rod is... l The range of values ​​is Where l is the number of possible values ​​for the thickness of the reinforcing rod, and d j Let d be the thickness of the base member, where j is the number of possible values ​​for the base member, and x is the minimum length of all members; the thickness d of different base members... j The value of l and the number of values ​​for the thickness of the reinforcing bar determine the type of bar S. i The number of design options for reinforcing bars;

[0012] For different base rod thicknesses d j And the thickness d of the reinforcing bar l By iterating through the values ​​of i, several rod types S will be formed. i Design scheme D ijl ;

[0013] Step 2: Simulation analysis; for the design scheme D ijl Mesh-based CAE analysis was performed to obtain stress-strain curves, thereby acquiring the S values ​​for different member types. i Design scheme D below ijl Yield strength β ijl ;

[0014] Step 3: Optimization of lattice structure thickness; based on member type S i And the thickness d of the base rod j Calculate the thickness d of different reinforcing bars l The limit factor for the improvement of relative yield strength μ ij :

[0015] μ ij =β ijl / β ij(l-1)

[0016] If μ ij =1+μ0, then μ ij Rod type S with value = 1 + μ0 i And the thickness d of the base rod j The optimal thickness of the lattice structure is selected, where μ0 is a constraint factor imposed by manufacturing process limitations and yield strength enhancement ratio limitations.

[0017] Furthermore, the dimensions of the base rod and the reinforcing rod are set as follows: the thickness d0 of the base rod is 0.1 times its length, and the rod thickness d of the reinforcing rod and the rod thickness d0 of the base rod satisfy the following:

[0018] The beneficial effects of this invention are as follows: This invention proposes a design method for an ultra-lightweight, high-strength, and damage-resistant lattice structure. By dividing the lattice structure into base rods and reinforcing rods, and considering the perforation of the lattice structure, manufacturing difficulty, and the increase in yield strength ratio, the optimal lattice structure thickness is obtained using the relative yield strength enhancement limit factor. This ultimately yields the thickness and length distribution of the lattice structure. The design method of this invention is simple, applicable to any lattice structure, and highly portable. It can bring the mechanical properties of the lattice structure close to the theoretical limit and maximize its performance while maintaining lightweight properties. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0020] Figure 1 The diagram shown is a flowchart of the design method for the ultra-lightweight, high-strength, and damage-resistant lattice structure of the present invention.

[0021] Figure 2 The diagram shown is a schematic representation of the distribution of the ultralight, high-strength, and damage-resistant lattice structure according to an embodiment of the present invention.

[0022] Figure 3 The figure shown is a graph illustrating the relationship between relative yield strength, constraint factor, and relative density / volume in Embodiment 2 of the present invention.

[0023] Figure 4 The diagram shown is a schematic of the optimal thickness scheme for the lattice structure in Embodiment 2.

[0024] Figure 5 The diagram shown is a structural relationship diagram of Embodiment 2 of the present invention;

[0025] Figure 6 The diagram shown is a load-bearing schematic of the lattice structure in Embodiment 2 of the present invention. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0028] like Figure 1 As shown, this embodiment provides a design method for an extremely lightweight, high-strength, and damage-resistant lattice structure, including lattice structure classification, simulation analysis, and optimal lattice structure thickness.

[0029] Step 1: Classification of the lattice structure; The structure is classified based on whether the direction vectors of each member are parallel, by extracting the direction vectors of all members. Choose any two members from the list.

[0030] If a m1 / a n1 =a m2 / a n2 =a m3 / a n3 If this is not true, then the two members belong to different types of members;

[0031] If a m1 / a n1 =a m2 / a n2 =a m3 / a n3 Based on this, the direction vector of the member is then calculated. With load vector The included angle θ i If the included angle θ between any two rods i If the two members are equal or complementary, they are classified as members of the same type; otherwise, they are classified as members of different types. For members of the same type, their thickness parameters are consistent.

[0032] Based on the obtained bar type S i Develop corresponding series of design schemes D ijl ;

[0033] Let the member type S i For reinforcement, the remaining member types S k (1≤k≤m, k≠i) represents the base rod, where 1≤i≤m, m is the number of rod types, and the thickness d of the reinforcing rod is... l The range of values ​​is Where l is the number of possible values ​​for the thickness of the reinforcing rod, and d jLet d be the thickness of the base member, where j is the number of possible values ​​for the base member, and x is the minimum length of all members; the thickness d of different base members... j The value of l and the number of values ​​for the thickness of the reinforcing bar determine the type of bar S. i The number of design options for reinforcing bars;

[0034] For different base rod thicknesses d j And the thickness d of the reinforcing bar l By iterating through the values ​​of i, several rod types S will be formed. i Design scheme D ijl ;

[0035] Step 2: Simulation analysis; for the design scheme D ijl Mesh-based CAE analysis was performed to obtain stress-strain curves, thereby acquiring the S values ​​for different member types. i Design scheme D below ijl Yield strength β ijl ;

[0036] Step 3: Optimization of lattice structure thickness; based on member type S i And the thickness d of the base rod j Calculate the thickness d of different reinforcing bars l The limit factor for the improvement of relative yield strength μ ij :

[0037] μ ij =β ijl / β ij(l-1)

[0038] If μ ij =1+μ0, then μ ij Rod type S with value = 1 + μ0 i And the thickness d of the base rod j The optimal thickness of the lattice structure is selected, where μ0 is a constraint factor imposed by manufacturing process limitations and yield strength enhancement ratio limitations.

[0039] Furthermore, the dimensions of the base rod and the reinforcing rod are set as follows: the thickness d0 of the base rod is 0.1 times its length, and the rod thickness d of the reinforcing rod and the rod thickness d0 of the base rod satisfy the following:

[0040] Example 2

[0041] For an FCC cell with dimensions of 5mm × 5mm × 5mm, the minimum length x of all members is 5mm. Considering manufacturing process limitations and yield strength enhancement ratio limitations, the constraint factor in this embodiment is μ0 = 0.14. Using the ultra-lightweight, high-strength, damage-resistant lattice structure design method of Embodiment 1, the number of member types m is 4, resulting in different member types S1, S2, S3, and S4, as shown below. Figure 2 As shown. The number of values ​​for the reinforcement rod thickness l is taken as 4, and the thickness d of the base rod is... j The values ​​are taken as 1mm, 0.6mm, and 0.4mm, meaning the number of base rod values ​​j is 3.

[0042] Furthermore, the simulation analysis module obtains different member types S i The following series of design schemes D ijl Yield strength as follows Figure 3 The diagram illustrates the relationship between relative yield strength, constraint factor, and relative density / volume for various design schemes of the 5mm×5mm×5mm cell size of this invention. Based on this, and using the FCC cell as an example, an extremely lightweight, high-strength, damage-resistant lattice structure is provided, such as... Figure 4 As shown. The basic FCC dot matrix structure's supports can be divided into horizontal diagonal braces 3, horizontal parallel braces 2, vertical braces 1, and vertical diagonal braces 4, as follows: Figure 5 As shown. The base rod 6 includes horizontal diagonal braces 3, horizontal parallel rods 2, and vertical diagonal braces 4, and the reinforcing rod includes vertical rods 1. The basis for obtaining the extremely lightweight, high-strength, and damage-resistant lattice structure is as follows: Figure 3 and 4 As shown, at μ0 = 0.14, the condition μ can be satisfied. ij The optimal lattice structure thickness is determined for a value of 1 + μ0. This design uses S1 members with a base rod diameter d = 0.5 mm. The minimum and maximum lattice structures for this ultra-lightweight, high-strength, damage-resistant lattice structure are shown in [reference needed]. Figure 4 The thickness of the base rods is 0.5mm, the minimum thickness of the reinforcing rod is 0.5mm, and the maximum thickness of the reinforcing rod is limited by the perforation of the lattice structure. The maximum thickness of the reinforcing rod should meet the following requirements: That is, the thickness of the largest reinforcing bar is no more than 4.29 mm.

[0043] See appendix Figure 4-6 For a unidirectionally loaded lattice structure, the external dimensions of the lattice structure are x mm × x mm × x mm, and the minimum length of the members is x mm. Assuming the force is applied from top to bottom, vertical member 1 will serve as reinforcing member 5, and horizontal diagonal members 3, horizontal parallel members 2, and vertical diagonal members 4 will serve as base members 6. Considering manufacturing process limitations and yield strength enhancement ratio limitations, the thickness d0 of base member 6 is fixed at 0.1x mm, while the thickness d of reinforcing member 5 is... maxThe value is selected based on the mechanical performance requirements, but it must satisfy:

[0044] It should be stated that the above-described specific embodiments are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art should understand that various modifications, equivalent substitutions, and variations can be made to the present invention. However, such variations, as long as they do not depart from the spirit of the present invention, should be within the scope of protection of the present invention. Furthermore, some terminology used in this specification and claims is not limiting, but merely for ease of description.

Claims

1. A method for designing a very light high-strength damage-tolerant dot-matrix structure, comprising dot-matrix structure classification and division, simulation analysis and dot-matrix structure thickness optimization, characterized in that: Step 1: lattice structure classification and division; according to whether the directional vectors of each rod of the lattice structure are parallel, the directional vectors of all rods are extracted any two rods are selected from the directional vectors If a m1 / a n1 = a m2 / a n2 = a m3 / a n3 is not true, then the two members belong to different types of members. If a m1 / a n1 =a m2 / a n2 =a m3 / a n3 Based on this, the direction vector of the member is then calculated. With load vector The included angle θ i If the included angle θ between any two rods i If the two members are equal or complementary, they are classified as members of the same type; otherwise, they are classified as members of different types. For members of the same type, their thickness parameters are consistent. Based on the obtained bar type S i Formulate a corresponding series of design schemes D ijl ; Set the rod type S i For the reinforcement rod, the rest of the rod type S k (1≤k≤m, k≠i) is the base rod, where 1≤i≤m, m is the number of rod types, the rod thickness d l The value range is Where l is the number of rod thickness values of the reinforcement rod, d j The rod thickness of the base rod, where j is the number of values of the base rod, x is the minimum length of all rods; the value of the rod thickness d j The value of the reinforcement rod determines the number of design schemes of the rod type S i When the reinforcement rod is For different base rods, the rod thickness d j and the rod thickness d of the reinforcing rod l , traverse the value of i, will form several design schemes D i of the rod type S ijl ; Step 2: simulation analysis; on the design scheme D ijl Grid CAE analysis to obtain stress-strain curve to obtain different rod types S i Design scheme D ijl Under the yield strength β ijl ; Step3: Lattice structure thickness optimization; based on bar type S i and base bar thickness d j , the relative yield strength enhancement limit factor μ l of different reinforcement bar thickness d ij : μ ij = β ijl / β ij(l-1) If μ ij =1+μ0, then the μ ij Rod type S with value = 1 + μ0 i And the thickness d of the base rod j The optimal thickness of the lattice structure is selected, where μ0 is a constraint factor limited by manufacturing process and yield strength improvement ratio.

2. The dot pattern design method according to claim 1, wherein: The base rod and the reinforcing rod are sized such that the thickness d0 of the base rod is 0.1 times the rod length thereof, and the rod thickness d of the reinforcing rod and the rod thickness d0 of the base rod satisfy:

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