Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2014-01-01

Journal: NUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS

Included Journals: EI、SCIE

Volume: 30

Issue: 1

Page Number: 158-174

ISSN: 0749-159X

Key Words: brick element; 14-point element; quadratic nonconforming element; second-order elliptic problem

Abstract: A new nonconforming brick element with quadratic convergence for the energy norm is introduced. The nonconforming element consists of P2 circle plus Span{xyz,x[x2-35(y2+z2)],y[y2-35(x2+z2)],z[z2-35(x2+y2)]} on a cube [-1,1](3), and 14 degree of freedom (DOF). Two types of DOF are introduced. One consists of the value at the eight vertices and six face-centroids and the other consists of the value at the eight vertices and the integration value of six faces. Error estimates of optimal order are derived in both broken energy and L2() norms for second-order elliptic problems. If a genuine hexahedron, which is not a parallelepiped, is included in the partition, the proposed element is also convergent, but with a lower order. Copyright (c) 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 158-174, 2014