Research On The Method Of Lightweight Model Based On 3D Printing

3D printing is a new manufacturing technology which has the advantages of low manufacturing cost,short processing cycle,strong innovation and so on.In the traditional manufacturing technology,the more complex of structure of the model is,the harder it is to manufacture,the higher the cost is.However,the cost of 3D printing has nothing to do with the complexity of the model,which is related to the volume of the model itself.Therefore,it is very important to study the lightweight of 3D model.In this dissertation,a lightweight design scheme is proposed to reduce the printing cost and ensure the physical properties of the printing model,according to the principle of 3D printing technology,and the main research contents are as follows:(1)The reading of binary STL model data is completed by using the MATLAB platform,the data is stored in the matrix,then the triangles are preliminary sorted in Z axis coordinate,the topological relationship matrix of STL is built by using the STL definition of law,it laid a good foundation for the subsequent offset algorithm.(2)The 3D print lightweight model is studied.The offset contour of STL is analyzed based on averaging method of vertex vector,then the bias in the process of intersecting facets are described.The triangles is judged by using the triangle of the intersection position relationship,then the excess cross section is removed.The offset model is obtained by Boolean operation between offset contour and the initial contour for STL,the above research is verified by examples.(3)A truss structure generation algorithm based on MATLAB and Grasshopper is proposed.The truss structure inside the model is established.Firstly,the inner contour is simplified,the simplified triangle vertex is taken as the initial node of truss structure.The topology is set up according to the adjacency relation of the upper triangular surface.Secondly,the data which is inserted from coordinates to grasshopper is grouped,the redundant data point line is deleted.Then,the three-dimensional model of the truss is generated.Finally,the interference nodes in the offset process are analyzed and removed.(4)The geometric optimization model of truss structure is put forward.According to the structural characteristics of truss,the mesh and the number of truss is optimized in the process of modeling,and then the volume of truss is optimized.This dissertation puts forward the evaluation index of triangular mesh,and the triangle model is established by using the difference of each triangle.The triangle of poor quality is searched by comparing the quality of triangle.The triangular mesh is optimized by using the minimum angle maximization method.Then,a simplified STL algorithm based on the topological relation of truss is proposed,the number of the truss rod connection layer merging is simplified by using topological relationship between vertex and triangle.Finally,the geometry optimization of truss is completed.