变系数三二次长方体有限元解最大模的超逼近

针对某种三维变系数二阶椭圆方程,利用三维投影型插值算子和插值逼近性质获得了长方体剖分下三二次长方体有限元的弱估计,进而结合三维离散Green函数获得了高精度逐点意义下三二次长方体有限元位移及梯度最大模的超逼近.

Maximum-Norm Superapproximation of the Triquadratic Block Finite Element Solution te the Three Dimension Problem with Variable Coefficients

For an variable coefficients elliptic equation in 3D,weak estimates for the block finite element over rectangular parallelepiped partitions of the domain are obtained by using three-dimensional interpolation operator of projection type and interpolating approximation properties.Furthermore,in combination with three-dimensional discrete Green functions,the author derives the maximum-norm superapproximation results with high accuracy of the displacement and gradient for block finite elements.