请教网格划分部分中“h单元”指的是什么单元

Darkwish

我想用ANSYS划分下网格，请教一下在《ANSYS工程结构数值分析》一书中“网格划分”那章里所指的“h单元”是什么单元？谢谢诸位老师

adidas023

H-单元和P-单元是有限元分析中的两个基本术语。简言之，后者是指通过提高单元形状涵数的阶（P-多项式阶数）而取得所需要分析精度的方法，有些书称为升阶谱有限元。前者相对后者而言，则采用提高单元密度，即在一定的区域上，采用更多的单元数，而取得所需要分析精度的方法（H-单元的最小外接圆、球的直径）。
如果您更加关心的是实际几何体的局部的详细应力的话, 那么您应该优先使用P单元和P方法. 您如果觉得载荷以及整个几何体的精度已经足够了的话, 那么可以优先使用H单元和H方法. 如果在几何体的局部区域有高的应力变化梯度的话, 那么使用混合的hp方法是最好的选择. 对更加关心的局部的区域使用P单元, 而整个几何体的其他部分都可以使用H单元.

The original and traditional finite element science is based on what are known as "h-elements." These h-elements represent a part's geometry as an assembly of multiple small elements. Subdivision of the part's geometry into a series of discrete elements is called meshing. Adaptivity helps achieve better answers.The relative simplicity of this representation allows efficient and direct solution of the analysis. In order to gain accuracy for complex geometries, additional elements must be added. This increase in the number of elements--either to represent complex geometry or to represent a highly varying stress gradient--increases the solution time and computer disk space required.
In the last several years, a new type of finite element, the "p-element," has gained acceptance in general FEA programs. Unlike h-elements, p-elements can directly represent curvature, resulting in simpler meshes containing fewer elements. Accuracy of the analysis is controlled by the p-level (polynomial) order assigned to each element: the higher the p-level, the greater the accuracy. In fact, an h-element can be viewed as a special case of p-element, where p = 1. With h-elements, solution time and disk space increase as the number of elements increase. With p-elements, the same phenomenon occurs as the "p order" is increased.One of the primary applications for p-elements is for complex stress fields where the geometry and environmental conditions must be represented very accurately. This includes modeling fillets instead of sharp corners and distributed loads and constraints instead of point loads and constraints. A more detailed model leads to more detailed results. With p-elements, adaptivity is achieved by increasing the p-level of selected elements, either by the user or automatically by the program, until the answers reach the specified convergence criterion--all without changing the mesh.

Ref.http://www.mscsoftware.com/support/library/wp/wp1.cfm
Ref.http://article.designnews.com.cn/2008-03/2008318100742.htm
Ref.http://www.chinavib.com/forum/thread-10240-1-1.html