Study of motions of a vibrating string subject to solid friction

摘要: In this paper we consider a string moving in its plane and subject to solid friction (Coulomb's law). It is known that when the time increases indefinitely reaches an equilibrium position by analogy with case of mass point ask if reached after finite time. We prove initially at rest 1. initial shape possesses second derivative bounded certain limits, or 2. formed two straight line segments. last section obtain some partial results polygonal line. The arbitrary still open problem.