Shaker Applied on System Identification of Vertical Machine Tool

• Main Authors: CHUEH, CHIH-HSUEH, 闕志學
• Other Authors: Liu, De-Shin
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/9fw43f

碩士 === 國立中正大學 === 機械工程系研究所 === 107 === The most popular method used in studying structural dynamic is experimental modal analysis (EMA). Traditional way of uses hammer as input source of EMA, however it requires a steady hand to guarantee same bandwidth and good coherence, even fully experienced person can’t keep the same result over and over again. In order to improve the reliability, an EMA method using thumper shaker as input source is proposed. First part of the thesis focusses on shaker’s driver program design, data processing and reliability verification; second part focus on practical usage on machine structural dynamic analysis including system contact stiffness and damping ratio identification. For first part of the thesis, shaker driver program is designed to acquire EMA data and carry out simple result in real time. After finishing the program design, its reliability is verified through comparing with EMA using impact hammer. Second part of the thesis build up a rigid-flexible hybrid multi-body dynamics model (hybrid MBD model). Contact stiffness identified by several other scholars is used as the initial value of the joints in hybrid MBD model. Further more, contact stiffness is verified through comparing frequency response analysis (FRA) of hybrid MBD model and EMA result acquired by shaker on real machine. At last, damping ratio is adjusted by computing quality factor of FRA result.