Perforated Nano-single Crystal Copper Curved Lvl Molecular Dynamics Simulation

Based on the present situations and developments on nanotechnology and nanomechanics, the bending and tension properties of single crystalline nano-copper that has a hole are simulated using molecular dynamics (MD) by self-organized program. By researching into the influences of microdefects and size effect in nano-scale on single crystalline nano-copper, many properties that are different from those of macroscopical scale are found and explained, which develops the insights into properties of materials in nano-scale.The method of MD is systemically represented in detail. The program of MD, which is designed with Visual C++, is approved to be feasible and right by simulating some properties of liquid Ar.Bending behaviors of single crystalline nano-copper cantilever beam models with hole are simulated by MD using embedded atom potential. Atom movements of the cantilever beam are motivated by applying transverse force on one end face while the other is fixed, and the clear atom deformation images are obtained. Displacement-load relations are analyzed and explained in a reasonable way. Results show that the microdefects have obvious affects on the performance of models and the combined impacts of size effect, surface effect, dislocation, slip and relaxation are the reason why the models have different mechanical properties in nano-scale from those of macroscopical scale. Bending processes of models of different slender proportions are researched, variant displacement-load curves indicate that slender proportion has big influence on bending performances of models. Besides, the variant slender proportions make the contribution of microdefects more obvious.Tensile strain processes of single crystalline nano-copper models of different slender proportions with hole are simulated by MD. Stress-strain relationships are obtained by forcing on one end face. Special tension properties of the single crystalline nano-copper are studied. The results show that, at nano-scale, models with smaller slender proportion have stronger elastic behavior at the initial stage of deformation, but are easier to enter plastic stage as strain increases. Models with hole are easier to generate dislocation that promotes plastic yield. At the meantime,differences of slender proportions make the effects of hole much heavier.