Applications of Molecular Dynamics Simulations in two Dimensional Frenkel-Kontorova Model

Based on the molecular dynamics simulation, this manuscript is dedicated to the studies of dynamical behavior in the two dimensional Frenkel-Kontorova model with triangular symmetric periodic substrate when a dc drive and a circular ac driven force are applied. The numerical results show that the velocity of system increases in quantized steps with step weights of < V >=n (0,1,2,3...). This ensures the reliability and accuracy of the scheme of our molecular dynamics code. As an important application, it is also obtained from our numerical results that the critical depinning force (known as the static frictional force in the tribology) can be strongly affected by the direction of the dc force. The obtained results show that the static frictional force is minimum value for alpha=0 degrees and 60 degrees. It are also noted that the curves are symmetric about alpha=30 degrees.