论文原文：The geogrid is a network structure made up of two-dimensional(2D)line elements. The T3D2 truss element, i.e. the 2-node linear 3D truss element,was used to divide the geogrid elements.Considering the computation effciency, the layout density of thegrid was determined by the mesh size of the grid. The partitioningtechnique was structured, and the grid partition is shown in Fig. 5a.The geocell is a 3D spatial network structure consisting of 3Dmembrane elements, and the M3D4 quadrilateral linear elementwas used to divide the geocell elements. The partition is shown inFig. 5b.
翻译：土工格栅是由二维线单元构成的网络结构。使用T3D2桁架单元（即两个节点的线性三维桁架单元）来划分土工格栅单元。为了提高计算效率，格栅的网格密度由网格尺寸决定。划分方式采用结构化划分，土工格栅的网格划分如图5a所示。土工格室是由三维膜单元构成的三维空间网络结构，使用M3D4四边形线性单元划分土工格室单元，土工格室的网格划分如图5b所示。
请问图（b）这种实体怎么做呢？按照原论文的要求应该是用壳单元制作但我做出来确是一块平板，而不是网格状。