Development of vibration Isolation system using high-performance damping metal

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 11554008
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: 素粒子・核・宇宙線
• Research Institution: The University of Tokyo
• Principal Investigator: MIO Norikatsu Univ. of Tokyo, Dep. of Advanced Materials Science, Associate professor, 大学院・新領域創成科学研究科, 助教授 (70209724)
• Co-Investigator(Kenkyū-buntansha): TAKAHASHI Ryutaro National Astronomical Observatory, Research associate, 位置天文天体力学系, 助手 (60270451) ; SUZUKI Toshikazu High Energy Accelerator Research Organization, Research associate, 助手 (20162977) ; TSUBONO Kimio Univ. of Tokyo, Dep. of Physics, Professor, 大学院・理学系研究科, 教授 (10125271) ; KAWAHARA Kouji BB Material, President, 代表取締役(研究職) ; MORIWAKI Shigenori Univ. of Tokyo, Dep. of Advanced Materials Science, Research associate, 大学院・新領域創成科学研究科, 助手 (60262044)
• Project Period (FY): 1999 – 2000
• Keywords: Damping metal / Vibration isolation system / gravitational wave detector

Research Abstract

Mechanical property of the damping metal M2052 was investigated. Its damping performance was quite well but sometimes degraded owing to plastic deformation or stress which was caused on the M2052 springs to support the weight of the mass.
The outgas rate was measured with several surface treatment methods. The measured outgas rate was about ten times larger than that of typical stainless steel. However, since the amount of M2052 is not so large, the effect due to the outgas from M2052 is not serious.
The prototype vibration isolation system was designed, assembled and tested. Because of the large loss of M2052, we have not observed no significant peaks showing spurious mechanical resonance; this improves the vibration isolation ratio at higher frequency than that of the fundamental resonance.
We have made an active vibration isolation system, where main structure was made of M2052. By optimizing the control loop, we have improved the vibration isolation by 20-40 dB. The damping performance of M2052 may increase the stability of the control system.
The non-linear characteristics of M2053 was investigated by a newly developed optical sensor in terms of time domain and frequency domain analysis methods. Since, the sensitivity of our sensor was quite good, we were able to measure the vibration in the amplitude range of three decades, where we have confirmed the non-linear anomaly at large amplitude and linear response at small amplitude.