Molecular dynamics simulation of micro frictional contact characteristics between tires and asphalt pavement

To accurately capture micro frictional contact characteristics and intermolecular forces between tires and pavement,the three-dimensional monomer models and the interface contact model of tires represented by isoprene and aggregates represented by silica were established by the molecular dynamics method.The microscopic structure and tire-aggregate contact properties were studied in nanoscale.Simulation results show that polyisoprene molecular chain is in the spiral structure with big molecular gaps,and is easy to generate large deformation under external loading.Conversely,silica is brittle with relatively flat surfaces.In the tie-pavement contact model,silica is the fixed base,and the single-chain polyisoprene is sliding on the top of the silica base at a constant velocity.The surface distance between the silica base and the single-chain polyisoprene is 0.5 nm.Simulation results of tire-pavement contact show that the friction coefficient decreases with the increase of sliding velocity,and the relationship between the friction coefficient and sliding velocity shows good agreement with test results,indicating that molecular dynamics simulation is capable to predict the tirepavement frictional contact characteristics.