中文摘要：

提出一种具有内部特征约束的四边形网格自动生成方法，可以处理内部具有孔洞、约束线、约束点以及密度线、密度点等特征约束，满足数值分析中对网格生成的特殊要求。以区域分解法为基础，提出了确定最佳切割线的方法以及在切割线上生成过渡均匀网格节点的方法；将约束线、约束点以及密度线、密度点作为面积为零的孔洞，提出了对特征约束的处理方法；针对特征约束分隔区域的情况，提出了自动确定各子区域边界的方法。基于本文提出的方法已开发出具有特征约束的四边形网格自动生成程序，并成功应用于洪水分析系统和楼面设计分析系统。

英文摘要：

An algorithm for quadrilateral mesh generation with internal feature constraints is presented in this paper. It can deal with all kinds of feature constraints such as internal holes, constraint lines, con- straint points, density lines and points etc. and satisfy the special requirements of mesh generation for nu- merical analysis. The method that determines the best cutting line and generates smooth transition nodes on it is given in this paper based on domain division algorithm. The method of dealing with feature con- straints is presented by regarding constraint lines and points and density lines and points as internal holes with zero area. For the condition that feature constraints separate the domain into sub-domains, the automatic determination method of sub-domain boundaries is presented. The program of quadrilateral mesh generation has been developed based on the algorithm in this paper and successfully applied to the flood analysis system and floor design and analysis system.