On the Error Estimate for the Isoparametric Finite Element Method

Abstract

In this paper, the isoparametric element of 2-degree Lagrange type for second order elliptic P.D.E, with nonhomogeneous Dirichlet boundary value is considered. We prove $\|u-u_h\|_{1,\Omega}=O(h^2)$, which is the same as $\|u-u_h\|_{1,\Omega_h}=O(h^2)$ where $\Omega$ and $\Omega_h$ in $R^2$ are the domain of the boundary value problem and isoparametric triangulation domain respectively.