Gillette Andrew, Rand Alexander, Bajaj Chandrajit
Department of Mathematics, University of Arizona, Tucson, AZ, USA,
CD-adapco, Austin, TX, USA,
J Comput Methods Appl Math. 2016 Oct;16(4):667-683. doi: 10.1515/cmam-2016-0019. Epub 2016 May 18.
We combine theoretical results from polytope domain meshing, generalized barycentric coordinates, and finite element exterior calculus to construct scalar- and vector-valued basis functions for conforming finite element methods on generic convex polytope meshes in dimensions 2 and 3. Our construction recovers well-known bases for the lowest order Nédélec, Raviart-Thomas, and Brezzi-Douglas-Marini elements on simplicial meshes and generalizes the notion of Whitney forms to non-simplicial convex polygons and polyhedra. We show that our basis functions lie in the correct function space with regards to global continuity and that they reproduce the requisite polynomial differential forms described by finite element exterior calculus. We present a method to count the number of basis functions required to ensure these two key properties.
我们结合多面体域网格划分、广义重心坐标和有限元外微积分的理论结果,为二维和三维一般凸多面体网格上的协调有限元方法构造标量值和向量值基函数。我们的构造恢复了单纯形网格上最低阶内德莱克(Nédélec)、拉维亚特 - 托马斯(Raviart-Thomas)和布雷齐 - 道格拉斯 - 马里尼(Brezzi-Douglas-Marini)单元的著名基,并将惠特尼形式的概念推广到非单纯形凸多边形和多面体。我们表明,就全局连续性而言,我们的基函数位于正确的函数空间中,并且它们再现了有限元外微积分所描述的必要多项式微分形式。我们提出了一种方法来计算确保这两个关键属性所需的基函数数量。