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Indexed by:期刊论文

Date of Publication:2012-10-26

Journal:INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING

Included Journals:SCIE、EI、Scopus

Volume:92

Issue:4

Page Number:399-424

ISSN No.:0029-5981

Key Words:meshfree; integration; Galerkin; finite element method; elasticity; solids

Abstract:The consistency condition for the nodal derivatives in traditional meshfree Galerkin methods is only the differentiation of the approximation consistency (DAC). One missing part is the consistency between a nodal shape function and its derivatives in terms of the divergence theorem in numerical forms. In this paper, a consistency framework for the meshfree nodal derivatives including the DAC and the discrete divergence consistency (DDC) is proposed. The summation of the linear DDC over the whole computational domain leads to the so-called integration constraint in the literature. A three-point integration scheme using background triangle elements is developed, in which the corrected derivatives are computed by the satisfaction of the quadratic DDC. We prove that such smoothed derivatives also meet the quadratic DAC, and therefore, the proposed scheme possesses the quadratic consistency that leads to its name QC3. Numerical results show that QC3 is the only method that can pass both the linear and the quadratic patch tests and achieves the best performances for all the four examples in terms of stability, convergence, accuracy, and efficiency among all the tested methods. Particularly, it shows a huge improvement for the existing linearly consistent one-point integration method in some examples. Copyright (c) 2012 John Wiley & Sons, Ltd.