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CN-121980685-A - High-strength energy-absorbing three-dimensional lattice cell design method based on nesting strategy and application

CN121980685ACN 121980685 ACN121980685 ACN 121980685ACN-121980685-A

Abstract

The invention discloses a high-strength energy-absorbing three-dimensional lattice cell design method based on a nesting strategy and application thereof, belonging to the field of structure lightweight design; performing numerical homogenization calculation on various nested cells, establishing mapping relation between stiffness coefficients and relative densities of the nested cells, constructing a mapping relation database, generating space coordinate matrixes of all the nested cells, obtaining a voxel unit density field and a voxel unit node displacement field through a topology optimization method, combining the mapping relation database, the density field and the displacement field, calculating strain energy at nodes of the nested cells to obtain an optimal configuration distribution field of a three-dimensional lattice structure model of the nested cells, and performing heterogeneous fusion on the nested cells to obtain the three-dimensional lattice structure model of the nested cells for designing or manufacturing aircraft components. The invention can realize the self-adaptive distribution of nested cell configuration and relative density in the design domain, and establish a complete lightweight design flow.

Inventors

  • LIU TINGTING
  • WANG JIEYUN
  • ZHANG CHANGDONG
  • LIAO WENHE

Assignees

  • 南京理工大学

Dates

Publication Date
20260505
Application Date
20260308

Claims (8)

  1. 1. A high-strength energy-absorbing three-dimensional lattice cell design method based on a nesting strategy is characterized by comprising the following steps: step 1, constructing a plurality of types of nested cells of a three-dimensional lattice structure model of the nested cells based on an implicit expression of a three-period minimum curved surface lattice, wherein the three-dimensional lattice structure model of the nested cells is used as a target model of an aircraft component; step 2, respectively carrying out numerical homogenization calculation on various nested cells, establishing a mapping relation between stiffness coefficients and relative densities of the nested cells, and constructing a mapping relation database; step 3, generating space coordinate matrixes of all nested cells according to the preset size of the nested cells and the scale of the three-dimensional lattice structure model of the nested cells, and obtaining a voxel unit density field and a voxel unit node displacement field through a topology optimization method; Step 4, combining the mapping relation database, the voxel unit density field and the voxel unit node displacement field, and calculating strain energy at each nested cell node to obtain an optimal configuration distribution field of the nested cell three-dimensional lattice structure model; And 5, carrying out heterogeneous fusion on the nested cells according to the voxel unit density field and the optimal configuration distribution field to obtain a three-dimensional lattice structure model of the nested cells, and outputting the model after the model is verified to be feasible for designing or manufacturing the aircraft component.
  2. 2. The nesting strategy-based high-strength energy-absorbing three-dimensional lattice cell design method according to claim 1, wherein the nesting cell in the step 1 comprises a shell structure and an embedded structure, wherein the embedded structure is generated by Boolean intersection of an entity and an internal supporting structure, PShell-type lattices are adopted by the shell structure and the entity, P-type lattices or IWP-type lattices are adopted by the internal supporting structure, and the ratio of the shell structure to the embedded structure is 40:60 or 50:50.
  3. 3. The nesting strategy-based high-strength energy-absorbing three-dimensional lattice cell design method according to claim 1, wherein the implicit surface equation of the nested cells in step 1 is that The method comprises the following steps: ; ; ; Wherein, the Is a hidden equation for the curved surface of the shell structure, Is a curved surface implicit equation of an embedded structure, Is any point coordinate in a Cartesian coordinate system, , For the characteristic length of the nested cells, Parameters describing the shape and surface area of the shell structure are shown, Representing the shortest distance to the surface of the housing structure for distinguishing between different areas of the housing structure.
  4. 4. The nesting strategy-based high-strength energy-absorbing three-dimensional lattice cell design method according to claim 1, wherein the step 2 specifically comprises: setting an elastic matrix of each type of nested cells, sequentially applying unit strain load to each node of the nested cells to obtain a rigidity coefficient, obtaining a mapping relation between the rigidity coefficient of the nested cells and the relative density by adopting trinomial fitting based on the relative density of the nested cells and the rigidity coefficient of each node of the nested cells, and constructing a mapping relation database.
  5. 5. The nesting strategy-based high-strength energy-absorbing three-dimensional lattice cell design method according to claim 1, wherein the step 3 specifically comprises: The method comprises the steps of carrying out hexahedral mesh division on a three-dimensional lattice structure model of a nested cell, carrying out hexahedral mesh division on voxel units with the same size as the size of the nested cell, carrying out cyclic marking on voxel unit indexes according to X-Y-Z directions, carrying out topological optimization on the three-dimensional lattice structure model of the nested cell by adopting a SIMP method, and outputting a voxel unit density field and a voxel unit node displacement field.
  6. 6. The nesting strategy-based high-strength energy-absorbing three-dimensional lattice cell design method according to claim 1, wherein the step 4 specifically comprises: Step 4.1, calculating and obtaining an elastic matrix of each type of nested cells according to a voxel unit density field and a mapping relation between rigidity coefficients and relative densities of each type of nested cells in a mapping relation database; And 4.2, calculating strain energy of each type of nested cells according to the voxel unit node displacement field and the elastic matrixes of each type of nested cells, and selecting the nested cells based on the maximum strain energy to obtain an optimal configuration distribution field of the three-dimensional lattice structure model of the nested cells.
  7. 7. The nesting strategy-based high-strength energy-absorbing three-dimensional lattice cell design method according to claim 1, wherein the step 5 specifically comprises: and 5.1, carrying out heterogeneous fusion on all nested cells based on a Gaussian radial basis function according to a voxel unit density field and an optimal configuration distribution field, wherein the Gaussian radial basis function has the following formula: ; The fusion function is: ; Wherein, the Is any point coordinate in a Cartesian coordinate system, Is the first The gaussian radial basis diffusion equation for nested-like cells, For parameters of the transition gradient for regulating the diffusion of the structure from the control point location to the surrounding area, Is the first The center coordinates of the class-nested cells, To obtain the integral implicit field function of the three-dimensional lattice structure model of the nested cells after fusion, For the total number of types of nested cells, Is the first Implicit surface equations for nested cells, For the characteristic length of the nested cells, Is the relative density of nested cells; And 5.2, performing performance contrast verification through finite element simulation of a single configuration gradient structure and a heterogeneous fusion gradient structure, and finally outputting a nested cell three-dimensional lattice structure model which is feasible to verify in a form of a target source file.
  8. 8. Use of a nesting strategy based high-strength energy-absorbing three-dimensional lattice cell design method according to any of claims 1-7, characterized in that the output nesting cell three-dimensional lattice structure model is used for industrial design of aircraft components or is produced to manufacture aircraft components by additive manufacturing processes.

Description

High-strength energy-absorbing three-dimensional lattice cell design method based on nesting strategy and application Technical Field The invention belongs to the technical field of structure lightweight design, and particularly relates to a high-strength energy-absorbing three-dimensional lattice cell design method based on a nesting strategy and application thereof. Background The nested cell design aims to break through the performance boundary of the traditional single configuration, and multiple cell units with different deformation mechanisms (such as bending dominant, stretching dominant or mixed modes) are organically integrated and configuration optimized in a three-dimensional space through an advanced space topology fusion technology. The design strategy focuses not only on the improvement of single performance index, but also on the realization of the coordination and balance of multiple functions such as bearing efficiency, energy absorption and the like in a macroscopic structure, so that a gradient and functional heterogeneous topological structure is constructed on the material distribution and mechanical response level. The nested cell design can effectively adapt to the comprehensive performance requirement of the spacecraft under complex load environments (such as extreme temperature, dynamic impact and multiaxial stress), and provides a key theoretical support and technical realization way for innovative design and engineering application of next-generation high-performance and multifunctional lightweight structures. However, the existing nested cell designs are limited to simple combinations of classical truss structures such as plates, beams and the like, and the study of topological fusion of triple period minimum curved surface (TPMS) type curved surface cells and truss type cells is not yet available. In addition, the existing design scheme generally depends on CAD software Boolean operation to complete geometric splicing, and due to the lack of a unified implicit parameterized mathematical characterization model, the nested interface is poor in continuity and limited in design space, and the follow-up efficient gradient optimization design is difficult to support. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a high-strength energy-absorbing three-dimensional lattice cell design method and application based on a nesting strategy, which can realize the self-adaptive distribution of nested cell configuration and relative density in a design domain, and establish a complete cross-scale lightweight design flow of a fine view lattice material and a macroscopic service structure so as to obtain a high-rigidity heterogeneous fusion three-dimensional lattice for designing or manufacturing an aircraft component. The invention provides the following technical scheme: in a first aspect, a method for designing a high-strength energy-absorbing three-dimensional lattice cell based on a nesting strategy is provided, which comprises the following steps: step 1, constructing a plurality of types of nested cells of a three-dimensional lattice structure model of the nested cells based on an implicit expression of a three-period minimum curved surface lattice, wherein the three-dimensional lattice structure model of the nested cells is used as a target model of an aircraft component; step 2, respectively carrying out numerical homogenization calculation on various nested cells, establishing a mapping relation between stiffness coefficients and relative densities of the nested cells, and constructing a mapping relation database; step 3, generating space coordinate matrixes of all nested cells according to the preset size of the nested cells and the scale of the three-dimensional lattice structure model of the nested cells, and obtaining a voxel unit density field and a voxel unit node displacement field through a topology optimization method; Step 4, combining the mapping relation database, the voxel unit density field and the voxel unit node displacement field, and calculating strain energy at each nested cell node to obtain an optimal configuration distribution field of the nested cell three-dimensional lattice structure model; And 5, carrying out heterogeneous fusion on the nested cells according to the voxel unit density field and the optimal configuration distribution field to obtain a three-dimensional lattice structure model of the nested cells, and outputting the model after the model is verified to be feasible for designing or manufacturing the aircraft component. Optionally, the nested cell in the step 1 comprises a shell structure and an embedded structure, wherein the embedded structure is generated by Boolean intersection of an entity and an internal supporting structure, PShell-type lattice is adopted by the shell structure and the entity, P-type lattice or IWP-type lattice is adopted by the internal supporting structure, and the ratio of the shell