Prevention of Low Frequency Vibration in a Vibroimpact System

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K06230
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Dynamics/Control
• Research Institution: Kyushu University
• Principal Investigator: Mori Hiroki 九州大学, 工学研究院, 准教授 (50451737)
• Co-Investigator(Kenkyū-buntansha): 近藤 孝広 九州大学, 工学研究院, 教授 (80136522)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 制振 / 振動機械 / 衝突 / 低周波振動

Outline of Final Research Achievements

The occurrence of the low frequency vibration in vibroimpact systems such as vibrating screens reduces the reliability of the system and precludes normal operation when its amplitude is excessive. For suppressing the low frequency vibration, this research analytically investigates the effect of a dynamic absorber on vibration characteristics. 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 effect of the parameters of a dynamic absorber mounted on the lower mass is examined, demonstrating that an optimal set of values for the natural frequency and the damping ratio to prevent the low frequency vibration is obtained by the proposed analysis. Experiments have also been conducted, showing a good agreement with analytical results.

Free Research Field

機械振動学

Academic Significance and Societal Importance of the Research Achievements

振動ふるいをはじめとする衝突振動システムは産業界で広く使用されており，その正常運転を妨げる低周波振動の効率的な防止方法を示した本研究の成果は大きな社会的意義をもつ．さらに，動吸振器は強制振動の低減や平衡点の不安定化に起因する一部の自励振動の安定化に対しては適用例が見られるものの，衝突をともなう周期振動の安定化に対する効果は不明な点が多く，その有効性を示したことは学術的にも意義があるといえる．