Research On Modeling Method Of Porous Structure

Porous structure is a three-dimensional network structure composed of a large number of pores.The modeling method of heterogeneous porous structure is studied,and the finite element method is used to analyze the mechanical properties of the porous element.Fusion of multiple triply periodic minimal surface based on interpolation method.By analyzing the topological connectivity of TPMS and using the idea of distance fusion,we design an artificial element to keeping TPMS topology.Combined with the theory of shape function,the assembly of artificial unit is realized.The main work as follows:(1)Design smallest element of porous structure.Firstly,the feasibility and superiority of TPMS as a pore structure are analyzed and the modeling and visualization of TPMS in MATLAB is realized.On this basis,we study the relationship between the parameters of implicit function and the shape of TPMS.The topological connectivity of TPMS is analyzed by using the method of center line and the method of element reduction.(2)Research fusion method of TPMS.Firstly,the linear interpolation method is proposed to fuse two kinds of TPMS.Using sigmoid function to optimize unideal interpolation results.Then the impact of the sphere partition method is proposed to fuse multiple TPMS.The fusion effect is controlled by setting the center and radius of the sphere.Finally,the voronoi diagran partition method is proposed to fuse multiple TPMS.The fusion effect is controlled by the coordinates of the seed points and the offset distance.(3)Research fusion method of distance.Firstly,design of artificial elements based on the topological connectivity of TPMS.Then,the realization of artificial unit assembly by using hexahedral mesh.After,the hexahedral mesh is refined by the refine template,and the porous structure with controllable cell density is designed.Finally,the delaunay algorithm is used to obtain the discrete tetrahedral mesh,and the random porous structure is designed with the shape function theory.(4)Analysis mechanical properties of elements.The effective Young's modulus is used to evaluate the mechanical properties.Firstly,the relationship between effective Young's modulus and element array is studied.The effective Young's modulus tends to be stable with the increase of the number of arrays.Then the relationship between effective Young's modulus and porosity is analyzed.The effective Young's modulus decreases with the increase of porosity.