Normal behavior of single-asperity contact of bcc iron: a molecular dynamics simulation study

Characteristics of contact surface are important for the operation of precision machines, which need to transmit force and torque, such as the interface contact between rotating disks of gas turbine rotor system. Meanwhile, the contact behavior of microscopic contact interface is proven to be different from that of macroscopic contact. This work presents molecular dynamic simulation of microscopic contact behaviors with single-asperity, including single-asperity contact with same asperity radius, single-asperity contact with different asperity radius and effect of overlapping ratio of the adjacent asperity. Through molecular dynamic simulation results, comparisons are conducted between microscopic contact and macroscopic contact behavior as well as evolution process of the dislocation. The simulation results show that dislocation has important effects on single-asperity contact, resulting in the reduction of contact force comparing to Hertz contact theory.