Stress analysis around a through crack shaped void in a single crystal copper strip coated on an infinitely stiff material using molecular dynamics

A small rectangular strip of fcc Cu, containing a through crack on the nanoscale and subjected to loading under displacement control, is simulated using molecular dynamics (MD). The geometry is highly constrained and chosen to mimic that of a thin film between two stiff layers. The Lennard–Jones pair potential is used for the inter-atomic forces. The centrally placed crack-shaped void is created by removing a few atoms inside the strip. The crack is loaded perpendicular to the crack plane and the variation of the tensile stress is studied. Also the elastic response for an uncracked strip is simulated using the same loading conditions. Comparisons with finite element (FE) calculations are made and the aim is to find a limit in model size beneath which the FE solutions and linear elastic fracture mechanics (LEFM) lose their accuracy.