Codice MOX 37 Titolo Reliability and efficiency of an anisotropic Zienkiewicz-Zhu error estimator Data 2004-04-16 Autore/i Micheletti, Stefano; Perotto, Simona Link Download full text Pubblicato Micheletti, S.; Perotto, S., Reliability and efficiency of an anisotropic Zienkiewicz-Zhu error estimator, Comput. Methods Appl. Mech. Engrg., 195 (2006), no. 9-12, 799-835 Abstract In this paper we study the efficiency and the reliability of an anisotropic a posteriori error estimator in the case of the Poisson problem supplied with mixed boundary conditions. The error estimator may be classified as a residual-basedone, but its novelty is twofold: firstly, it employs anisotropic estimates of the interpolation error for linear triangular finite elements and, secondly, it makes use of the Zienkiewicz-Zhu recovery procedure to approximate the gradient of the exact solution. Finally, we describe the adaptive procedure used to obtain a numerical solution satisfying a given accuracy, and we include some numerical test cases to assess the robustness of the proposed numerical algorithm.