衝突系に発生する低周波異常振動に関する研究

（変分のエネルギーに及ぼす衝突の影響）

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 show that the mechanical energy of the small variation increases with the low frequency vibration. An analysis is also made on the relationship between the time-phase-averaged and the phase-averaged mechanical energy of the small variation, which demonstrates that the phase-averaged one is usable for evaluating the development of the low frequency vibration. 九州大学 Kyushu University