基于STL文件的变密度三维全六面体网格自动生成方法

针对STL文件在传递复杂几何实体模型信息方面具有精度较高的特点，提出了一种基于STL文件变密度三维全六面体网格自动生成方法，给出了STL文件的数据格式及其内容约定，详细阐述了基于STL文件空间CAE模型表面特征自动识别、拓扑关系的生成和变密度栅格法加密信息场的建立等关键技术。实现了在实体模型表面曲率较大和厚度较小的局部区域进行协调加密，可以获得与实体模型边界吻合良好的全六面体协调网格，适合于工程问题的有限元分析计算。若干复杂实体模型算例表明，该算法实用性强，效果良好。

Automatic Density-changed All-hexahedral Element Mesh Generation Algorithm Based on STL File

Because STL file can transfer the information of solid model accurately, an algorithm to gener ate density-changed three-dimensional all-hexahedral element meshes based on STL file was proposed. Several key technologies were presented, such as the automatic identification of surface geometric characteris tics and topology in three-dimensional CAE model based on STL files, the construction of refinement metric for density-changed grid-based method and so on. A conformal refinement of the local meshes was realized at the areas where large curvature and small thickness existed. Therefore, all-hexahedral element conformal meshes, which were accurately matched to the boundary of the solid model and suitable for finite element a nalysis, can be generated automatically. The effectiveness of the algorithm and the quality of the mesh generation are demonstrated by using several complex examples.