Research On 3D Printing Adaptive Layering Algorithm And Forming Direction Optimization Method

As a rapid prototyping technology,3D printing has been widely used in various fields because of its layered and superimposed processing method,which makes it unnecessary to go through the traditional process of mold opening,casting and cutting of equal and reduced materials,and greatly reduces the R&D cost and cycle of products.At the same time,it also breaks through the restrictions of complex structure on the processing process.In 3D printing,a series of data processing are needed to transform the model into machine-identifiable codes for physical printing.Therefore,the data processing process has a crucial impact on the printing accuracy and printing efficiency.Based on this,thesis study the data processing process,focusing on the hierarchical algorithm and the optimization method of molding direction.First of all,an in-depth analysis of the STL file format is made.In view of STL file’s data redundancy,lack of description of topological relationship and other shortcomings,a method is investigated to establish the topology structure,by which the function of reading STL file and the establishment of topology construction are realized,and the STL model visualization is completed through the use of Open GL graphics library.Secondly,several existing adaptive stratification algorithms are analyzed.Aiming at the problem that the current algorithms can only prevent the deviation and loss of the conventional feature points,feature lines and feature planes,an adaptive stratification method based on volume error rate is proposed to preserve the unconventional features of the model.Firstly,the model features are identified according to the general definition and layered at the height of the features,and then the model is again stratified by using the volume error rate beteen every two adjacent feature heights.This method can not only effectively prevent the deviation and loss of conventional features,but also guarantee the loss of unconventional detail features that do not meet the conventional definition,so that the printing error can be controlled within a given range.Then,the influence of molding direction on molding accuracy and efficiency is analyzed in this thesis.The molding precision is quantified as the model volume error and the molding efficiency was quantified as the relative printing time,and then their mathematical model is established combining with the improved adaptive hierarchical algorithm.Finally,the optimal molding direction of the model under the adaptive hierarchical algorithm is optimized by using linear weighting method and multi-objective particle swarm optimization algorithm(MOPSO).Finally,combined with the improved adaptive stratification algorithm and the optimization method of forming direction proposed in this thesis,a 3D data processing software is developed to realize the STL model visualization,constant thickness and adaptive stratification,filling and result display functions,and the software functions are demonstrated through an example model.