讨论了四阶非线性双曲方程在半离散格式下的非协调有限元逼近,借助ACM单元的非协调性,得到了最优误差估计,超逼近和超收敛结果.同时利用Bramble-Hilbert引理,构造了一个新的合适的外推格式,得到了比通常收敛性高一阶的超收敛结果.
A nonconforming finite element method approximation to nonlinear fourth-order hyperbolic equation is discussed for semi-discrete scheme.Based on the nonconforming property of the ACM's element,the optimal order error estimates,superclose and superconvergence are derived.At the same time,by virtue of the Bramble-Hilbert lemma,the research has constructed a new and suitable extrapolation scheme and obtained a superconvergence result which is higher one order than the usual convergence.