Meshing Method Based On Complex Parts And Its Software Implementation

The finite element method has important applications in both academia and industry.It is widely used in simulation and calculation and analysis in engineering cases,and plays a very important role in computer-aided design.When the analysis problem is two-dimensional,triangular meshes and quadrilateral meshes or a hybrid mesh of the two are usually used for analysis.Quadrilateral meshes have higher calculation accuracy,mesh quality level and geometric regularity.More and more planar finite element analysis cases use quadrilateral meshes to geometrically discretize the model;when the target area and geometric model are three-dimensional,three-dimensional tetrahedral mesh elements,three-dimensional hexahedral mesh elements,or mixed mesh pairs are usually used.The geometric model is discretized.Compared with the tetrahedral grid element,the hexahedral grid has higher convenience and accuracy in calculation,and it is not easy to produce large-scale deformation and distortion.The first choice for problem analysis.Compared with the generation technology of triangular and tetrahedral elements,the development and research of the generation technology of quadrilateral and hexahedral grid elements are still insufficient at this stage.The importance of industry is very prominent.Among the existing quadrilateral mesh generation technologies,the indirect generation of quadrilateral mesh elements represented by the technology of remerging two-dimensional triangular meshes to generate quadrilateral meshes and the algorithm of generating hexahedral mesh elements based on quadrilateral meshes are similar to other similar techniques.Algorithms have significant advantages.Compared with other technologies and algorithms,the coincidence method usually consumes less time,requires less computing performance,and is less difficult to implement.Based on these advantages,this paper conducts in-depth research and software implementation of the algorithm based on the re-merging of triangular meshes to generate hybrid meshes and pure quadrilateral meshes.implement it in software.Compared with other algorithms for generating 3D hexahedral mesh elements,the algorithm and technology for generating hexahedral meshes by stretching and rotating based on the feature information of quadrilateral meshes and geometric models have better adaptability to special features of geometric models and are less difficult to implement.,the requirements for computer performance are lower and the time cost of the overall mesh generation process is also lower.Algorithms for quality optimization of cells were studied and implemented in software.This paper uses the stack structure design path to traverse the existing twodimensional triangular meshes;re-merge new quadrilateral mesh elements by deleting the common edges between adjacent triangular mesh elements;the quadrilateral meshes calculated separately The quality coefficient β of the grid cell and the quality coefficient β^*of the common side are compared.After comparing various possible merging methods,select the method with the highest quality to re-merge to obtain quadrilateral grid elements;re-merge the overall triangular grid elements that meet the requirements to obtain New quad mesh element.The algorithm based on the existing two-dimensional triangular meshes to re-merge to generate hybrid meshes and pure quadrilateral meshes with mixed triangular mesh elements and quadrilateral mesh elements is realized,and the software is written to realize it.By adjusting the position of grid nodes,eliminating special nodes contained in unsatisfactory grid cells,deleting local grid cells,and comparing the grid nodes connected to surrounding grid nodes under various internal division methods of this group of grid cells The number of adjacent mesh elements is used to re-division the local mesh,delete internal edges,and re-division the area composed of the surrounding local adjacent quadrilateral meshes to optimize the quality of the local low-quality mesh.and implemented in software.On the basis of the existing quadrilateral meshes,the method of generating 3D hexahedral meshes by stretching means is studied by combining the geometric feature information of the geometric model.Enter the extruded features of the model and label the model;generate extruded mesh nodes according to the model classification,and connect to obtain a three-dimensional hexahedral mesh;use high-order elements to replace low-order elements for lower-quality parts,and perform re-segmentation optimization Local mesh quality.Based on the above methods,the method of realizing three-dimensional hexahedral mesh division by stretching method based on the existing twodimensional quadrilateral mesh and model geometric characteristics of the model is realized,and the software is written to realize the specific realization.The rotation equations and rotation matrices of the rotation of the vector around any rotation axis in the two-dimensional and three-dimensional spaces are studied;the rotation features and information of the geometric model are entered and marked,and the source surface,the trajectory surface and the target surface of the rotation operation are distinguished;Enter the rotation information and the existing quadrilateral mesh,rotate the existing quadrilateral mesh elements and nodes,generate mesh nodes layer by layer,and connect the mesh nodes to obtain 3D hexahedral mesh elements;for low-quality parts,use High-order elements are replaced by low-order elements and re-segmented to optimize local mesh quality.Based on the above methods,the method of realizing the three-dimensional hexahedral mesh division by the rotation method based on the existing two-dimensional quadrilateral mesh of the model and the rotation feature of the model is realized,and the software is written to realize it.Based on the above research results and content,the finite element processing meshing software JSLMESH was written,and the software copyright was applied;the JSLMESH software was used to mesh the specific geometric models in the project,and the obtained meshes were compared with existing mature commercial software.The mesh quality and mesh shape of the two are compared,and the reliability and practicability of the research content and the specific software implementation are verified.