A tribological application of the coarse-grained molecular dynamics simulation and its experimental verification

We developed a method to simulate the polytetrafluoroethylene (PTFE) tribology by estimating the molecular interaction parameters on the basis of experimental verification. We fitted the molecular interaction parameters between coarse-grained PTFE beads using the iterative Boltzmann inversion method and multi-centered Gaussian-based potentials. The fitting parameters were subsequently validated by comparing an all-atom PTFE model and its corresponding coarse-grained model. A two-layer PTFE friction model was then built on the basis of the estimated parameters to study the effect of normal load on the friction coefficient and wear depth of PTFE. The simulation results showed that the friction coefficient decreases and the wear depth increases as the normal load increases. Moreover, the reasonability of the simulation results was verified through experiments.