Molecular Dynamics Simulation Of Single Crystal Copper’s Crack Propagation Under Tensile And Bending

Single crystal copper with its excellent electrical and signal transmission performance and the characteristics of corrosion and fatigue resistance, and it has been widely used in national defense technology and civil electronic and network communication, etc. But in the process of preparation of single crystal copper nanometer materials, it’s easily to produce some micro defects such as cracks structure, which will make a difference to the mechanical properties of the material. Therefore, the analysis around the microstructure damage of single crystal copper, is gradually becomes a hotspot of research interests.This topic by using molecular dynamics simulation software LAMMPS, simulated the change of the crack propagation of single crystal copper on nanometer scale respectively with different configurations and stress. Based on the calculation of the radial distribution function(RDF) and center symmetry parameters, we can analyze the system configuration changes in the extension process including germination of dislocation structure, dislocation emission and atomic relaxation of the crack tip and crack propagation phenomena, etc. Meanwhile, the stress change and energy change have been lucubrated in the process from the relaxation to load until structure failure. From different angles, dislocation evolution and the essence of the crack propagation in the process of crack propagation is concluded some conclusions.The stress variation in the system causes configuration change, configuration changes will lead to the change of the overall system potential energy. The stress concentration at the crack tip is the main cause of the crack propagation, and crack propagation is also changes with the evolution of the crack tip region of stress concentration. Such as atomic relaxation and dislocation structure on both sides of the crack tip and neutron crack initiation and crack extension process of passivation phenomena, they are all the ends of the evolution of crack tip stress concentration area with external load.