DEFORMATIONS AND DYNAMICS OF AN ELASTIC STRING IN A PERIODIC POTENTIAL

We study the dissipative dynamics of a driven elastic string subject t o a periodic potential. The deformations of the elastic string are det ermined in the static and dynamic situations for various geometries. W e find the average velocity of the string, particularly the dependence of the velocity on the mean angle theta between the string and the po tential. Our theoretical analysis produces both a sharp drop in the av erage velocity at small angles due to the trapping of the elastic stri ng in the potential and a crossover from free motion to a pinning-inhi bited motion at the critical driving ford.