Abstract
This paper deals with experimental identification of the stiffness and damping in dynamic collision between a slider and a magnetic disk whose substrate is Al and glass. From comparison of the six different damping force models, it is found that the contact force due to penetrating depth can be estimated by Hertzian contact theory and that the damping force is proportional to velocity and contact area. The effective damping coefficient in repulsing process is more than two orders larger than that in penetrating process in an Al disk. The damping of glass disk is almost zero. The damping effect at collision is caused not by lubricant, but by a small deformation hysteresis of the coated layer and substrate.
