The Performance Of Single Crystal Copper In Process Of Tension And Sliding Friction Using Molecular Dynamics Simulation

Simulation using computer is a perfect method of researching the mechanical property of materials on microscopic level . Nanotribology researches the behavior, impairment and resource of friction, which occurred on friction surface on scale of atoms and molecular. It is significant thing to study the characteristic of materials, and profoundly reveal the mechanics of tribology.With molecular dynamics method and computer, nature of single crystal copper material during the tension and friction process was performed on nanoscopic level. It was chiefly studied that defects in material affect the mechanics'performance of material. By creating study mode, I had simulated the formation of adhesion and the separated of two parts by loading and the process of sliding friction on contact face.Firstly we selected embedded atom potential function as the interacted model, deduced the expression of applied force between two atoms; and plotted the potential function and fore among two atoms. Then using molecular dynamics method, simulated that how the existence of defect influence the mechanical property of single crystal copper by programming VC++. It indicated that defect in the material had greatly influence on the mechanic property. The Young's modulus and breaking stress of materials would decreased obviously with bigger and more flaws.This paper studied the phenomenon of adhesion and the process of sliding friction, directly present the variation of atoms'positions in the process of simulation and research the different of frictional behavior under the condition with different surface topography and different normal pressure. The result indicated that external applied load had function by applied force to atoms; the contact force in on the contact surface was originated from the force among atoms.It increased and achieved the most value along with the increasing of external applied load for separating two parts. Statistic found that the frictionhave related with the actual contact plane, not the apparent contact surface. The normal pressure increased, so the actual contact surface enlarged and made friction force increased. But it have deeply infect on friction performance of model, by impacting the defects in the material. The frictional force of gliding is the tangential force, which is needed that the rough block is divorced from basal body.