Abstract
Mechanism of damping is studied in this paper form the both viewpoints of micro and macro. First, it is explained how viscosity originates in the potential energy field caused by van der Waals gravity and electronic exchange rejection force among atoms and molecules. Second, it is described how viscous damping force proportional to velocity is caused by shear displacement between atomic rows accompanying material rearrangement. Third, role of viscosity in the free vibration is related. Forth, it is explained how amplitude increases infinitely in the resonance of forced vibration of undamped system. Fifth, the process is shown by which damping makes the resonance stable in forced vibration, and its mathematical expression is given.
