Mechanical properties of single crystal copper ellipsoidal nanoshells by molecular dynamics

Single crystal copper ellipsoidal nanoshells under outer normal tensile loadings are investigated by the molecular dynamics method. Normal stress and Mises stress are introduced to describe the mechanical properties. The uniform thickness nanoshells, the variable thickness nanoshells and the variable radius nanoshells are simulated to elucidate the effect of thickness on yielding behaviors and other mechanical properties. Potential energies, stresses and dislocations of nanoshells are discussed in the paper. The dislocations of these nanoshells form an octagon or that with an external quadrangle. The variable thickness nanoshells break this shape slightly. The potential energies of nanoshells have stable stages and then increase. The outer normal stresses and Mises stresses of different models differ from eath other. The thickness of nanoshells affects the elastic stage and the variable thickness nanoshell has different mechanical properties with others. When the radiuses of nanoshells with the same thickness are different, their dislocation shapes are the pressed octagon. Thier normal yield stresses are different, but their Mises yield stress are same. Also, the outer shape determines the trend of curves. The structure of a sphere is steadier than that of an ellipsoid.