Molecular Dynamics-based Tensile Mechanical Beha-vior Of Metal Nanowires

In this paper,the mechanical behavior of nanomaterials under tensile loading is studied by molecular dynamics.The stress-strain curves,atomic energy diagrams,and microscopic deformation of the system are analyzed under the change of temperature,size and strain rate.The research content and main conclusions are as follows:(1)The study on the tensile simulation of nano alpha wire of body centered cubic structure shows that within the scope of this simulation,the internal local structure of the material changes from BCC to FCC at the time of yield stress 7.453GPa and fracture stress 13.52GPa.As the strain increases,there will be some movement.When the slip zone is about to disappear,the structure of the slip band will change again.The 45 degree slip band appeared at 0.1K.With the increase of temperature,the smaller the initial modulus of elasticity of the material,the increase of the size will not affect the modulus of elasticity;the increase of strain rate will reduce the elastic modulus of the material gradually.(2)The study on the tensile simulation of the nano copper wire in the face of the cubic structure shows that the nanostructure material in the process of relaxation has a small size and the existence of its surface effect,so that the atom in the corner has a trace structural deformation.In the scope of the simulation,the local structure changes from FCC to HCP when the yield stress 6.89GPa is reached during the tensile process of nanoscale copper wire.Especially in the special strain time of 100K and 300K,there is a 45 degree slip band.At different strain rates,a very small number of structural changes,are changed from FCC structure to BCC structure,and the number of slip bands increases with the increase of strain.With the increase of temperature,the yield strength and modulus of elasticity of the material gradually decrease,and the modulus of elasticity will not change with the change of the size of the material,and the modulus of elasticity decreases with the increase of strain rate.