Pertinence of the grains aggregate type on the self-consistent model responses A. Abdul-Latif * L3M, IUT de Tremblay, GIM, Rue de la Raperie, 93290 Tremblay-en-France, France Received 9 September 2003; received in revised form 9 September 2003 Abstract The effect of the aggregate of grains type (i.e., the number and the orientation of grains) on the non-linear strain– stress behavior of FCC polycrystals is of particular interest in the present work. In this context, a well established self- consistent model, proposed by the author and co-workers [J. Appl. Mech. 69 (2002) 309] is used. This model is tested under different complex cyclic loading paths with strain and stress-controlled conditions describing especially the multiaxial ratcheting behavior of stainless steel 316L which represents also another main goal of this work. In order to study the aggregate effect on the overall and local responses of polycrystals, several initially random crystal distribu- tions are tested under these loading situations. It is recognized that the model shows a noticeable sensitivity to the aggregate type principally under stress-controlled cyclic loading paths. Accordingly, it can be considered that the ag- gregate of grains represents a model parameter needing identification. Moreover, the connection between the aggregate constitution and the form of the loading paths play also an important role on the predicted responses of polycrystals. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: Self-consistent model; Aggregate influence; Multiaxial ratcheting; Local heterogeneity 1. Introduction The mechanical responses of single or poly-phase polycrystals are typical examples of heterogeneous behavior of such material at their local geometry. In term of the irreversible behavior, their inelastic flow is a manifestation of their heterogeneity and their discrete and heterogeneous deformation pattern at the microscale. This leads, in general, to strengthening and workhardening of polycrystals. At the granular level, the heterogeneity comes widely form the differences in the orientation of the grains and the single- crystal anisotropy since the morphology and spatial distribution of the grains are not taken into account. Crystals are consequently heterogeneous and some crystals deform differently than others inducing highly non-uniform strain fields. Hence, the knowledge of the local heterogeneities is considerably important in modeling of the overall stress–strain behavior of polycrystals. The exact solution for the local fields in these * Tel.: +33-1-41-51-12-34; fax: +33-1-41-51-12-49/48-61-38-17. E-mail address: aabdul@iu2t.univ-paris8.fr (A. Abdul-Latif). 0020-7683/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.ijsolstr.2003.09.014 International Journal of Solids and Structures 41 (2004) 305–322 www.elsevier.com/locate/ijsolstr