Design method for variable relative density octet lattice structure

Abstract

The invention discloses a design method for a variable relative density octet lattice structure. The method comprises the steps that the equivalent mechanical property of a lattice material is extracted by adopting a representative volume element method, the equivalent mechanical property of the lattice material is subjected to normalization processing, a lattice material punishment model is obtained, the model is directly applied to a lattice structure optimized mathematical model, the structure minimum flexibility optimization problem is solved by adopting an optimization criteria method, optimal material distribution is achieved, gradual deletion operation is used for conducting multistage deletion on a thin rod element, and finally the variable relative density octet lattice structurewith the gradient density is generated on the basis of an original uniform lattice structure. Under the same material volume, compared with a uniform lattice structure with optimal macroscopic topology, the variable relative density lattice structure obtained through the method has the better mechanical property and rod stress condition.

Description

technical field [0001] The invention relates to the minimum flexibility optimization problem of octet lattice material structures under the action of static load, in particular to a design method of variable relative density octet lattice structures, which is applicable to the mechanical performance design of various tensile-dominated lattice structures. Background technique [0002] As a new type of ultra-light structure, the lattice structure has excellent specific stiffness / strength, damping and vibration reduction, sound absorption and heat insulation and other multi-functional application potentials, and is increasingly used in industrial fields such as automobiles, ships, and aerospace. . However, in practical engineering applications, due to the limitation of traditional manufacturing processes, commonly used lattice structures often only have a single relative density. In comparison, the variable relative density lattice structure has more variable structural forms ...

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Problems solved by technology

The two-dimensional material / structure hierarchical topology optimization method is mainly based on the homogenization theory, and the homogenized elastic tensor is obtained under the condition of known microscopic cell structure form, which is used to solve the topology optimization problem of the macroscopic structure, but the homogenized elastic tensor and the structure The solution to the sensitivity of the response function is very complicated, and the optimal shape and direction of the micro-units are difficult to determine, resulting in a complicated implementation and solution process of homogenized topology optimization

Although the multi-scale finite element method and the two-dimensional material / structure parallel optimization design method can give the best cell configuration and macro topology, the relative density of the cell is still single

The multi-scale isotropic geometric topology optimization design method (IPO) can design a two-dimensional lattice structure with variable relative density and optimal macroscopic configuration and material distribution on the basis of a given cell configuration, but for solving three-dimensional The optimal design of lattice structures still needs further study

Most of the methods or models in other relevant literature are limited to two-dimensional scale or single relative density. At present, the application potential of three-dimensional lattice structure with variable relative density has not been fully understood at home and abroad, and there are few studies on related optimal design methods.

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