Modelling Simul. Mater. Sci. Eng. 6 (1998) 755–770. Printed in the UK PII: S0965-0393(98)97151-0 Mesoscopic scale simulation of dislocation dynamics in fcc metals: Principles and applications M Verdier†‖, M Fivel‡ and I Groma§ † LTPCM Domaine Universitaire-BP 75 38402 St Martin d’H` eres Cedex, France ‡ GPM2 Domaine Universitaire-BP 46 38402 St Martin d’H` eres Cedex, France § Institute for General Physics, Eotvos University, H-1445 Muzeum krt. 6–8, Budapest VIII, POB 323, Hungary This paper is dedicated to Gilles Canova, who initiated and participated in the development of the numerical simulations presented in this paper. Received 14 June 1998, accepted for publication 27 August 1998 Abstract. This paper reviews the methods and techniques developed to simulate dislocation dynamics on a mesoscopic scale. Attention is given to techniques of acceleration and to the implementation of special boundary conditions. Typical results concerning the deformation of a bulk crystal, the effect of image forces and the combination with a finite-element code to simulate the indentation test are presented. The limits and future development of each application are discussed. 1. Introduction Dislocations are the vector for plastic deformation in crystalline solids and in materials where the long-range interactions between dislocations dominates, as in, for example, most face-centred-cubic (fcc) metals where the emergence and evolution of a heterogeneous microstructure of dislocations governs mechanical properties. At the mesoscopic scale, i.e. the scale between the atomic level and the macroscopic level of the mechanical properties, the basic entity is the dislocation line. The dislocations interact through a long-range stress field (in 1/r ), and as a non-conservative N -body problem it is difficult to treat analytically. Therefore, with the aim of studying the self-organizing patterns of the dislocation structure and their influence on the mechanical properties of a single crystal, a framework for a three-dimensional (3D) numerical simulation of dislocations on a mesoscopic scale has been developed in the past few years [1]. This work has recently been reviewed [2]. A different version of this simulation has recently been developed to test an acceleration scheme required to reach some larger strain [3]. Moreover, to study physical problems where a high density of dislocations in the volume simulated is not required, such as the role of interfaces and the indentation test, some complex boundary conditions have been developed and implemented [4–6]. In the present paper, we first briefly review the key elements for such simulations, emphasizing the different techniques that we have developed. Then, we present the different boundary conditions developed in this simulation for the case of ‖ Present address: Los Alamos Nal Lab, CMS, MS:765, Los Alamos, NM 87545, USA. 0965-0393/98/060755+16$19.50 c  1998 IOP Publishing Ltd 755