Hemispherical surface boundary structure design method for 3D printing design

Abstract

The invention provides a hemispherical surface boundary structure design method for 3D printing design and belongs to the technical field of digitized manufacturing. The hemispherical surface boundary structure design method comprises the specific implementation steps that 1, grid subdivision of hemispherical projection is performed; 2, plane coordinate points are converted into coordinate points of a hemispherical surface; 3, a lattice structure is formed. In the step 1, two mutually-perpendicular directions in a plane M are selected, and gridlines on the plane M are formed according to the set side length L, wherein the grids included by the plane can completely cover a projected round plane S; In the step 2, the hemispherical surface extends properly to enable all vertexes of the whole grids to be mapped out; in the step 3, for each grid, a small piece of curved surface is separated out of the spherical surface and is the bottom surface of a hexahedral lattice, the curved surfaces are offset according to the heights of the lattices, namely the top surfaces of the hexahedral lattices are obtained, and accordingly a self-adapted lattice area is obtained. The hemispherical surface boundary structure design method has an important reference value for single-deformation-extremum curved surface subdivision of hemi-ellipsoidal surfaces and the other relative single projection planes and has great significance on structure design.

Description

technical field [0001] The invention relates to a structural design method based on hemispherical quadrilateral subdivision and a hexahedral lattice as a basic unit. It is a structural design oriented to 3D printing technology and belongs to the technical field of digital manufacturing. Background technique [0002] With the maturity of 3D printing technology, it has been able to directly manufacture fine and complex structures. This kind of new lattice-like structure that changes adaptively with a given boundary, compared with traditional materials such as metal foam, is easy to calculate the mechanical properties, and will be widely used in composite materials, optimization of weight reduction, etc., in aviation, aerospace, automotive areas have received widespread attention. [0003] The hexahedral lattice structure design of the hemispherical boundary, the most critical part is the quadrilateral grid division of the (hemispherical) surface. At present, there are mainly...

AI Technical Summary

Problems solved by technology

At present, there are mainly the following types of methods: (1) Longitude and latitude grid division, its disadvantage is that the grid deformation is large, and the shape of the grid at the poles and the equator is very different, especially at the north and south poles, the grid degenerates from a quadrilateral to a triangle ; (2) Regular polyhedron grid subdivision, most of the current research is based on spherical triangular grid, and there are few studies on other grids such as rhombus and hexagon, and the calculation is heavy due to the complex coordinate conversion; (3 ) The traditional adaptive spherical grid subdivision provides a supplement to the regular grid subdivision. Its disadvantage is that it is only suitable for a local small-scale spherical surface

Specific quadrilateral subdivision methods include "ETP projection method", "ZOT projection method", "column approximation method", "three-way interchange algorithm", etc. These grid subdivision methods come from technical fields such as geography, meteorology, and communication , the method of hierarchical subdivision is adopted, that is, the current subdivision result is the basis of the next level subdivision, and the discretization of the grid side length is very serious, which cannot meet the structural design requirements

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