Method of Preventing Unstable Vibration Caused by Time Delays in Contact Rotating Systems

In the field of mechanical engineering, a large number of systems exhibit time delays caused by, for example, viscoelastic deformation, plastic deformation, cutting, grinding, and wear. These time delays often cause unstable vibrations during the operation of these systems. Such phenomena occur as the chattering of machine tools and as the pattern formation phenomena in contact rotating systems. In the present report, the authors investigate the property of a new stability analysis developed for unstable vibration in contact rotating systems and apply it to a system with a time delay of one half of a rotation period. As a typical example, a prevention method used to change the structural design is formulated for two- and three-DOF systems. The validity of the present method is confirmed by the results of numerical computations.