衝突系に発生する低周波異常振動に関する研究

（力学的エネルギーに関する検討）

抄録

This paper examines the characteristics of the low frequency vibration which occurs in a vibroimpact system. The system investigated comprises two masses which can move only in the vertical direction under gravity. The lower mass is supported by a spring and subjected to a periodic exciting force whereas the upper mass bounces freely on the lower mass. The results of stability analysis show that the low frequency vibration occurs in the parameter range where unstable periodic solutions exist. An analysis is also made on the relationship between the change in the mechanical energy and the behavior of the small variation of state variables, which demonstrates that the average value of the fluctuating mechanical energy increases with the low frequency vibration.