The study of deformation and stress-strain distribution of nano-scale thin sheet copper under the biaxial tensile loads by using molecular dynamics and finite-element method

摘要

This paper investigates the strain and stress distributions in a nano-scale copper thin sheet under the biaxial tensile action, within the range of elasticity, by employing the molecular dynamics (MD) and finite-element method (FEM). Each atom is regarded as a node and the lattice as an element. The nano-scale copper thin sheet model, established in this study, is based on the face centered cubic lattice structure, and divides the lattice into 24 constant strain tetrahedron elements. After MD simulation, the biaxial force is found to be almost the same during the biaxial tensile action. Simulation results reveal that the stress and strain are highly closer at the edge of the sheet. The presence of strain around the upper and lower surfaces in the central region of the thin sheet indicates that after exhibiting biaxial tensile activity, contraction occurs in the region. The FEM/MD model, constructed in this paper directly melts the FEM spirit in MD computation. This facilitates the analysis of stress and strain in the entire nano-scale range for the nano-scale copper thin sheet.