The Frenkel–Kontorova–Tomlinson model is used to study the interface between two rigid sliding bodies. It consists of a chain of equal particles of mass connected by springs of strengths and damping force proportional to velocity. Each mass is coupled with a spring to the body at the top that moves at constant velocity . The interaction with the body at the bottom is represented with a periodic potential of amplitude , with equal to the ratio of lattice constants. Open boundary conditions are used.