Research On Visualization And Forming Path Planning Of Heterogeneous Material Parts Based On Discrete Element

Modern industry has higher and higher requirements for product performance.Parts made of single material have been difficult to apply to some special service environment.In order to meet the functional and performance requirements of parts,people put forward the concept of "heterogeneous material parts",which refers to the functional parts composed of continuous or discontinuous distribution of multiple materials inside the parts.With the development of additive manufacturing technology,multi-material additive manufacturing technology came into being,which provides a new method of the preparation of such parts.This technology can form heterogeneous material parts with complex material properties and more functions,such as multi-material parts with obvious material spacing,functionally gradient parts with gradient distribution of materials and composite material parts.In this paper,a software system with independent intellectual property rights is designed and developed to realize the functions of model visualization,slicing and path generation of heterogeneous parts,which is based on multi-material additive manufacturing technology Part manufacturing provides the technical basis.The main tasks are as follows:1.Combining STL file with the modeling idea of material mapping,by establishing the mapping relationship between geometric space and material space,selecting the geometric features of the model as the gradient reference,constructing the material distribution function with geometric distance as the independent variable,through the material component value and corresponding function,the corresponding geometric space corresponding to the given material component value can be determined,and the geometric information of heterogeneous material model can be realized Combined with the complete expression of material information,the paper puts forward the corresponding countermeasures for the mathematical expression of three kinds of material mapping: single dimensional material change,multi-dimensional independent change and multi-dimensional composite change,and establishes the representation methods of material distribution area division and material components in the area.2.The discrete material forming process is abstracted from the additive manufacturing process,and the solid discrete method is proposed.Firstly,the model is discretized in one dimension to get the contour of each layer,then the contour of each layer is discretized in two dimensions to get the internal discrete points,and then the discrete points are filtered and filled into three-dimensional discrete units to achieve the volume data rendering of the model.Finally,the material attributes are added to the discrete model to achieve the goal Visualization of heterogeneous materials.3.Based on the discrete element,two different forming paths,manufacturing first and material precision first,are proposed.For the former,the complex material area is divided into a series of sub areas with similar material properties,each sub area is filled according to the single material forming process,and Fermat spiral path is introduced to realize continuous filling in the area.For the latter,the material precision is further improved,the "filling path" of equal material area is transformed into the "connecting point path" of equal material unit,and the collision detection theory is introduced to realize multi nozzle printing.4.Under the development platform of visual studio,the user interface of 3D printing parameter setting is realized by using python,the model data processing is carried out by using C + +,the model visualization,hierarchical processing and path generation are realized based on Open GL and other graphic libraries,and finally the data files recognized by the rapid prototyping equipment are generated.