Automatic Generation Algorithm And Implementation Of 3D Printing Support Structure

The 3D printing technology is an advanced manufacturing technology through stacking materials layer by layer to produce objects,based on the digital model technique.During the 3D printing process,parts often have problems such as deformation,warpage,collapse,and finally failure in forming.In order to solve these problems,it is necessary to add supporting structures to assist in processing.This paper focuses on the structural design,generation algorithms and other related technologies of 3D printing process support.The content of this paper is as follows:Because the columnar support structure has good heat dissipation,and it is used more in the SLM process,and a columnar support generation algorithm is proposed.First,the support points were evenly distributed and filled with rays.The support rays and the triangular faces are intersected to obtain the support line segment,and the radius value is set to construct the cylindrical support bar.Finally,in order to facilitate the removal of the support structure,the contact part between the support structure and the body were optimized.The tree-shaped support was a multi-level support structure.Compared to a columnar and other projection support structure,the tree support could save processing materials and time,but its structure was complicated.The algorithm complexity by the optimal tree-like support structure is at least NP difficulty.The tree support structure generation algorithm was based on the critical inclination angle constraint condition.A mathematical model was established to solve the nodes at each level of the support structure,and the optimal tree support structure was approached with greedy algorithms and iterative approaches.For a complex model with the convex structure,a voxelization optimization tree-shaped supporting generation algorithm was used.The voxel method was used to judge the positional relationship between the supporting branches and the solids,avoiding the interference between the support and the solids,ensuring the rationality of the tree-shaped supporting structures,and enhancing the robustness and applicability of the algorithm.In order to facilitate the path planning and processing of the model and support structure,the SLC and STL file output algorithms of the support structure were proposed.The SLC format outputs algorithm of the support structure,the mature Clipper library was used to perform Boolean operations on the slice outline.The STL format output algorithm of the support structure.the idea of parametric modeling was adopted,on base of the simple model to construct the support structure.And using the features of the OpenSCAD software modeling by scripts,firstly OpenSCAD the support structure scripts were generated,then STL files were generated using OpenSCAD software.Based on the above research,we have independently developed a support generation module for 3D printing process software using VS2010 and OpenGL software platform.