In the algorithm , the convexity - concavity of vertexes and arcs must be identified , and a fast approach for identifying the convexity - concavity of line - arc closed curve is proposed . firstly , the orientation of a closed - curve is determined by constructing a new convex polygon . secondly , by using the orientation of the closed curve the convexity - concavity of vertices and arcs are identified 在算法实现过程中，由于需要对圆弧和直线段组成的封闭曲线的顶点、圆弧的凸凹性进行判定，本文提出了一个圆弧和直线段组成的封闭曲线凸凹性快速判定方法，该方法首先通过构造一中介凸多边形求出封闭曲线的方向，然后根据封闭曲线方向确定顶点及圆弧的凸凹性，进而确定封闭曲线的凸凹性。
The details as followed : 1 . summarize and analyze the methods of meso - mechanics of concrete and researching documents on the theory of damage of concrete ; 2 . based on the packing approach of spherical aggregates , a method generating polygon aggregate model of concrete was presented , by which the codes of aggregate packing and meso - meshes of finite element plotting were designed taking into account the actual aggregate content , grading , and aggregate configuration 具体工作由以下几个方面: 1 .分析总结了混凝土细观力学分析方法和现有混凝土材料损伤破坏理论的研究成果; 2 .在研究圆形骨料投放方法的基础上,提出了一种多边形随机骨料投放方法,并编制了凸多边形模型生成程序和细观有限元剖分程序。这种生成方法所得到的凸多边形骨料模型既反映了骨料的实际形态又维持骨料的实际级配和含量。
Cross section is a set of polygons and for this reason some relative algorithms for polygon are studied firstly . new algorithms for orientation and inclusion test for simple polygon are proposed . and ghosh ' s convex hull algorithms for simple polygon and convex polygons , subramanian ' s triangulation algorithm for arbitrary planar domain and o ' rourke ' s intersection algorithm for convex polygons are modified to make them more robust 断层轮廓为简单多边形，首先对多边形的一些相关算法进行了研究，提出了一种判断简单多边形方向及点在多边形内外的新方法，改进了subramanian的平面多连通域的三角划分方法、 ghosh的多边形的凸包及多个多边形的凸包算法和o ' rourke的凸多边形的求交算法。
