We construct conforming finite element elasticity complexes on Worsey-Farin splits in three dimensions. Spaces for displacement, strain, stress, and the load are connected in the elasticity complex through the differential operators representing deformation, incompatibility, and divergence. For each of these component spaces, a corresponding finite element space on Worsey-Farin meshes is exhibited. Unisolvent degrees of freedom are developed for these finite elements, which also yields commuting (cochain) projections on smooth functions. A distinctive feature of the spaces in these complexes is the lack of extrinsic supersmoothness at subsimplices of the mesh. Notably, the complex yields the first (strongly) symmetric stress element with no vertex or edge degrees of freedom in three dimensions. Moreover, the lowest order stress space uses only piecewise linear functions which is the lowest feasible polynomial degree for the stress space.
翻译:我们在Worry-Farin的分裂上建造符合限制元素弹性复合体,分三个维度。在变形、不兼容和差异的不同操作器中,迁移、紧张、压力和负荷的空间与弹性复合体是相连的。对于每个组成部分空间,都展示了Worry-Farin meshes上的相应有限元素空间。为这些有限的元素开发了单溶自由度,这些元素也得出通勤(连锁)对平滑功能的预测。这些复合体空间的一个显著特征是,在网状子的子部位上缺乏外特异性超大移动性。值得注意的是,综合体产生第一个(强度)对称压力元素,在三个维度上没有脊椎或边缘自由度。此外,最低的电压空间只使用小线性函数,这是压力空间最低可行的多球度。