Rate dependent deformation of a silicon nanowire under uniaxial compression: Yielding, buckling and constitutive description

This paper investigates the effect of compressive strain rate on the mechanical behaviour of single crystalline silicon nanowires using molecular dynamics simulation. It was found that of the whole range of the strain rates studied, the initial deformation of a nanowire is elastic. At lower strain rates the nanowire exhibits greater elasticity, and simple constitutive equations can be developed to describe the nanoscale structure and its deformation mechanism. With the increase in strain rate, the buckling stress increases and becomes steady at medium strain rates. On applying a very high strain rate, which is equivalent to a mechanical shock, the maximum buckling stress has a sudden rise and the silicon nanowire undergoes ballistic annihilation at both ends.