讨论了非线性双曲方程的Hermite型矩形有限元逼近。利用该元的高精度分析、平均值理论和导数转移技巧得到了H1模意义下的超逼近性。借助于插值后处理方法导出超收敛结果。最后,通过构造一个新的外推格式,给出了与线性问题相同的四阶外推估计。
A Hermite-type rectangular finite element approximation is discussed for nonlinear hyperbolic equation. The superclose property in H1 -norm is obtained by use of high accuracy analysis of the element, mean-value theorem and the derivative transfering technique. The superconvergence result is derived with interpolation postprocessing method. Final- ly, the fourth-order extrapolation estimation which is as same as that of the linear problem is deduced through construc- ting a new extrapolation scheme.