Abstract: With the high accuracy of computer-based collecting device, the damping coefficient is measured and the theory that the damping coefficient fl remains constant in damped vibration is revised. A linear relation of β and the velocity amplitude A is presented based on the data obtained. A further experiment is performed in which the linear relation of β and A is confirmed by the measuring of instigative force and velocity amplitude under the state of resonance. Considering the relation of β and A, the differences of the results obtained by the two traditional ways are explained.

Key words: damping coefficient, tuning fork, nonlinear vibration, sound card collection