Molecular dynamics simulations of dry friction dampers with coating

To study and simulate its mechanical characteristics of dry friction process, the shear movement of nanoscale asperities was studied. A molecular dynamics model was created. This model predicted shear movement of two hemispherical deformable asperities by adopting a suitable potential. Shear and normal forces during shear movement of two single-crystal copper asperities were analyzed. The residual deformation energy after the movement was also studied. A dry friction model based on nanoscale asperities was developed through multi-scale analysis and statistical methods. And its results were compared with experimental results. The following conclusions were summarized. In case of dry friction of single-crystal copper in vacuum, the normal contact stiffness on joint surfaces and normal load were in direct proportion, while sliding coefficient of friction was only relevant with surface roughness. The results of simulation were coincident with the results from pure copper friction experiments. This method was proved to be able to analyze dry frictional characteristic of dry friction damper working surfaces covered by wear-resistant coating accurately. For surfaces with known micro parameters, this method can predict the sliding coefficient of friction accurately.