| With the rapid development of modern science and technology,lightweight design plays an important role in energy conservation and environmental protection and reducing production cost.Lattice structure has been widely used in lightweight design because of its light weight and high efficiency.Compared with the uniform density lattice structure,the variable density lattice structure redistributes the materials through the analysis of structural mechanical properties,so the variable density lattice structure has more scientific material utilization and better mechanical properties.Triply periodic minimal surface is a special kind of approximate equivalent surface,which changes periodically in three-axis direction,has excellent structural characteristics,and the surface itself does not intersect,so triply periodic minimal surface has great potential in lattice structure design.This paper presents a lightweight design method of the three-period minimal surface variable density lattice structure driven by load.The main works are as follows.(1)Based on the mathematical theory of triply periodic minimal surface and the modeling of equivalent surface,this paper analyzes the modeling algorithm of marching cubes and the configuration of triply periodic minimal surface from the perspective of equivalent surface modeling,and analyzes the influence of parameters in the function on surface modeling in mathematical function.(2)Based on the stress balance of elastic body and the theory of finite element method,the calculation method of element bearing capacity is studied,and the calculation formula of element bearing capacity based on the theory of finite element method is deduced.The calculation and extraction algorithm of finite element bearing capacity based on element "life and death" technology is compiled and visualized based on APDL secondary development language,The evaluation function of element bearing capacity on structural bearing capacity is analyzed.(3)Based on the principle of marching cubes equivalent surface modeling algorithm and the bearing capacity characteristics of structural elements,an element over smoothness treatment method is proposed to solve the mutation problem of the bearing capacity of structural elements in the constraint support and load application position,so as to ensure the over smoothness of surface elements with different densities,A variable density porous structure modeling strategy is proposed to determine the porosity.(4)The mechanical experimental verification scheme is designed.Taking the bending of cuboid structure as an example,the variable density and uniform density lattice models of sheet and Skelton with porosity of 60% are constructed.Printing and manufacturing with photosensitive resin,the feasibility of this method is verified by the comparative analysis of finite element static analysis and mechanical compression experiment. |
