Modified h-method with directional error estimate for finite element stress analysis

An effective directional error estimator, based on Zienkiewicz-Zhu's error estimate, is presented for the h-method of the adaptive finite element analysis. The estimator allows Zienkiewicz-Zhu's error to be effectively separated into directional components in the global coordinate system and can be easily combined with existing h-refinement algorithms. A modified h-method, where a selective refinement algorithm is adopted with the directional error estimator, is thus proposed in order to improve the performance of h-refinement. Through various numerical tests for three kinds of isoparametric elements such as four-node plane, eight-node brick and four-node shell elements, the suggested algorithm shows the remarkable validity and cost-effective characteristics in adaptive mesh refinement. (C) 1997 Elsevier Science Ltd.