geometric symmetry meaning in English

几何对称

On the assumption of ignoring the distortion of thickness , this paper determines the rough shape by the geometric modeling method of equal area developing using mixed mesh cell of triangle and quadrangle for the first time , presents the equal area developing arithmetic of quadrangle - triangle . on the virtual geometric symmetry axis , we puts forward the method of determining the developed coordinate of the point on the base band in the development of using regular quadrangle cell , determines the developed shape of internal structure in plane utilizing point - to - point mapping theory . furthermore , we realize the approximate developing of undeveloped - irregular boundary surface using a few triangle cells
本文结合型号研制中小曲率机翼整体壁板类零件坯料展开课题，基于板料厚向变形忽略不计的先验假设，首创混合四边形-三角形网格等面积展开的几何模拟法确定壁板类零件毛坯外形，给出了混合四边形-三角形网格等面积展开算法；提出了虚拟分割线的概念，采用虚拟几何对称轴，给出了规整四边形单元展开基带上结点的计算方法；采用映射原理和求交算法确定了壁板内部结构信息的展开定位。