Abstract
Intermittent crystalline plasticity with power-law behaviors, which is reminiscent of self-organized criticality, has been reported in recent experimental and numerical studies. In this study,we showthat the compressiveloading condition can provide different statistical features of intermittent plasticity in metals from those under tensile loading. Employing an embedded atom method potential for aluminum we performed molecular dynamics simulations for uniaxial tensile and compressive deformation. It is shown that the power spectra of tensile stress have power-law decay region. Power-law distribution of stress drop and waiting time of plastic deformation events are also observed. However, under the compressive loading large-scale deformation events which result in a plateau and larger cutoffon the stress drop distri.bution are observed. This difference is originated from the geometrical feature of slip systems that dominate interaction between dislocations in crystals.
