Molecular-dynamics study of nanofragmentation during relaxation in after-loaded solids

The possibility of nanofragmentation development during the initial relaxation stage in the subsurface layer of a solid after preliminary loading is studied by computer simulation using the molecular dynamics method. It is established that disoriented nanoblocks can form in the initial stage of relaxation. This fragmentation arises in the region of strain localization in the vicinity of stress concentrators and then spreads in depth of the material. In the region of strain localization, the radial distribution function (RDF) of atomic density exhibits smeared maxima corresponding to peaks in the RDF of the ideal fee crystal structure. In the crystal region free of strain localization, the RDF peaks exhibit splitting caused by the strain-induced symmetry breakage. The obtained results suggest that fragmentation is the possible mechanism of relaxation of internal stresses in loaded solids.