Strain rate effect on tensile behavior of the helical multi-shell gold nanowires

A molecular dynamics simulation of the helical multi-shell (HMS) gold nanowires for tensile behavior has been carried out at 4 K temperature. HMS nanowires, not like bulk face centered cubic (FCC) structure, have a multi-shell helical structure. This work compares mechanical properties and deformation behaviors of the 7-1, 11-4 and 14-7-1 multi-shell helical structure under different strain rates. The results reveal that the different strain rate influence the maximum stress, Young's modulus and deformation behaviors. The Young's modulus and maximum stress of HMS nanowires are function of the ratio of numbers of surface atoms to the total number of atoms, but tubular 11-4 HMS nanowire is an exception. For different strain rate, many different deformation behaviors are appear which include sliding, multi-sliding, phase transformative, twisting, necking and brittle deformations before breaking.