Tensile behavior of single-crystal nano-sized copper beams with voids

The tensile response under displacement controlled loading of nano-sized single crystal Cu beams, solid or holding square shaped through-the thickness voids, have been investigated through 3D molecular dynamics simulations using free-ware LAMMPS [1]. For the same beam size and void height, the void width along the beam length axis was varied. Two different crystallographic orientations were considered. It was found that, under some circumstances, voids were able to close and heal the beam cross section, causing final failure through necking in the region of the initial void. For other cases instead the void split in two, smaller voids that both eventually healed. A third scenario was that the void widened, splitting the beam in two ligaments that each necked individually. As expected, both defect geometry and crystal orientation influences the mechanical behavior.