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论文类型：期刊论文

发表时间：2001-01-01

发表刊物：INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS

收录刊物：Scopus、SCIE、EI

卷号：25

期号：1

页面范围：29-48

ISSN号：0363-9061

关键字：uniqueness analysis; strain localization; saturated porous medium

摘要：Conditions for localization of deformation into a planar (shear) band in the incremental response of elastic-plastic saturated porous media are derived in the case of small strains and rotations. The critical modulus for localization of both undrained and drained conditions are given in terms of the discontinuous bifurcation analysis of the problem. Loss of uniqueness of the response of coupled problems is investigated by means of positiveness of the second-order work density. From the discussion of drained conditions, it is shown that there are two critical hardening moduli, i.e. lower and upper hardening moduli which, respectively, correspond to single phase material (large permeability) and to undrained conditions (small permeability). In analogy to one-dimensional results, it is shown that there exists a domain of permeability values where we have loss of stability, but the waves can still propagate. In this domain finite element results do not show pathological mesh dependence, and permeability will play the role of an internal length parameter in dynamic models. The length scale prediction is thus given for multi-dimensional problems. Copyright (C) 2001 John Wiley & Sons, Ltd.