A Note on the Quadrilateral Mesh Condition $RDP(N,\psi)$
Keywords:
Isoparametric finite element, Optimal order error estimate, Quadrilateral mesh condition.Abstract
The main aim of this paper is to show that the quadrilateral mesh condition $RDP(N,\psi)$ is only sufficient but not necessary for the optimal order error estimate of the $Q_{1}$ isoparametric element in the $H^{1}$ norm.