title: Finite-size effects in a model for plasticity of amorphous composites.
abstract: We discuss the plastic behavior of an amorphous matrix reinforced by hard particles. A mesoscopic depinning-like model accounting for Eshelby elastic interactions is implemented. Only the effect of a plastic disorder is considered. Numerical results show a complex size dependence of the effective flow stress of the amorphous composite. In particular, the departure from the mixing law shows opposite trends associated to the competing effects of the matrix and the reinforcing particles, respectively. The reinforcing mechanisms and their effects on localization are discussed. Plastic strain is shown to gradually concentrate on the weakest band of the system. This correlation of the plastic behavior with the material structure is used to design a simple analytical model. The latter nicely captures reinforcement size effects in (logN/N)(1/2), where N is the linear size of the system, observed numerically. Predictions of the effective flow stress accounting for further logarithmic corrections show a very good agreement with numerical results.
authors.affiliation: Laboratoire PMMH, CNRS-UMR 7636/ESPCI/UPMC/Univ. Paris 7 Diderot, 10, rue Vauquelin, 75231 Paris cedex 05, France.|Babeş-Bolyai University, Department of Physics, 1 str. Mihail Kogălniceanu, 400084 Cluj Napoca, Romania.
authors.forename: Botond
authors.initials: B
authors.lastname: Tyukodi
authors.affiliation: DNRF Centre "Glass and Time," IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark.
authors.forename: Claire A
authors.initials: CA
authors.lastname: Lemarchand
authors.affiliation: DNRF Centre "Glass and Time," IMFUFA, Department of Sciences, Roskilde University, Postbox 260, DK-4000 Roskilde, Denmark.
authors.forename: Jesper S
authors.initials: JS
authors.lastname: Hansen
authors.affiliation: Laboratoire PMMH, CNRS-UMR 7636/ESPCI/UPMC/Univ. Paris 7 Diderot, 10, rue Vauquelin, 75231 Paris cedex 05, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Vandembroucq