장비기초의 진동저감설계를 위한 구조적 진동에 관한 연구

초록

Dynamic loading of the floor and the foundation caused by Bogie Dynamic Test Machine (BDTM) is expected to excite vibrations that may adversely affect research activities using equipment supported on the foundation. Further, vibration from BDTM of the laboratory sites can be transmitted through the ground to neighboring residential sites. Therefore, the design of the machine foundation and structure supporting BDTM requires the proper assessment of the vibration properties of the structural system to ensure that no resonance condition will be encountered during machine operating conditions. The dominant modes of vibration, usually associated with the global structural modes of vibration, can be easily identified by inspection of the natural frequencies and mode shapes with high participation factors, and checked against the machine supplier frequency criteria. On the other hand, the identification of the natural frequencies of individual structural members becomes more involved since low participation factors are associated with these high frequencies modes. An FE model of the floor is developed and modal testing is conducted on the floor to obtain dynamic characteristics. The structural integrity of the floor and foundation during the two extreme loading conditions, which are dynamic test operation and sudden drop or release at the wheels while suspended by safety slings from the overhead support structure, are considered. In this paper, a methodology for the accurate determination of the local structural vibration modes and details of the implementation of the proposed methodology are presented"