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.
Phys Rev E. 2016 Feb;93(2):023004. doi: 10.1103/PhysRevE.93.023004. Epub 2016 Feb 8.
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.
我们讨论了由硬颗粒增强的非晶基体的塑性行为。实现了一个考虑埃舍尔比弹性相互作用的介观去钉扎模型。仅考虑了塑性无序的影响。数值结果表明,非晶复合材料的有效流动应力具有复杂的尺寸依赖性。特别是,混合定律的偏离表现出与基体和增强颗粒的竞争效应分别相关的相反趋势。讨论了增强机制及其对局部化的影响。塑性应变逐渐集中在系统中最弱的带。这种与材料结构相关的塑性行为用于设计一个简单的分析模型。该模型很好地捕捉了数值上观察到的(logN/N)(1/2)中增强体尺寸效应。考虑到进一步的对数修正,有效流动应力的预测与数值结果非常吻合。