针对基于CAD几何信息的网格剖分方法无法避免繁琐模型修补,导致网格剖分效率低下的现状,提出一种基于散乱模型的全四边形网格剖分方法。使用散乱点或者STL格式文件作为网格剖分的输入模型,使用改进的基于散乱模型进行网格剖分的铺路算法,在很大程度上减少甚至避免了模型修补问题。提出以散乱模型作为背景网格,作为控制网格单元尺寸调整的依据;使用网格细分和网格粗化的手段实现网格疏密变化的光滑过渡;自动识别几何模型中的特征并在网格模型中保留。提出了一种高效的铺路面相交搜索方法,综合考虑影响相交处理的多种因素,有效地处理了铺路面相交问题。多个复杂的汽车覆盖件网格剖分的算例结果表明,运用所提出方法完成的网格模型质量很高,算法具有较强的工程实用性。
Because of the inevitable tedious model repair by using CAD model as the source for mesh generation, an algorithm of generating all-quadrilateral element mesh from discretized models is proposed. By this method, discretized models, such as scattered points or STL file format model, are used as the source for mesh generation, and the original mesh generation paving method is modified to handle discretized models. Several key technologies are presented, the first one is the control of mesh size by using the discretized model as background mesh, the second one is the adjustment of mesh density distribution by mesh refinement and coarsening operation, and the third one is automatic identification of surface features in discretized models and preservation in mesh models. A new method to search intersections between paving boundaries is proposed. The effectiveness of the algorithm and the quality of the mesh generated are demonstrated by using several complex examples.