An Equivalent Reduced System for Coupled Vibration Analysis

• Published in: Transactions of the Japan Society of Mechanical Engineers Series C Vol. 54; no. 499; pp. 587 - 595
• Main Authors: MATSUSHITA, Osami, SUGAYA, Toyomi, NAMURA, Kiyosi, OKABE, Akira, KANEKO, Ryouichi, MICHIMURA, Seiichi, IDA, Michiaki
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Mechanical Engineers 25.03.1988
• Subjects: Blade-Shaft Coupled Vibration; Eigensolution; Reduced Model; Vibration of Rotating Body
• ISSN: 0387-5024; 1884-8354
• DOI: 10.1299/kikaic.54.587

Coupled vibration problems in large scale mechanical or rotor systems are often encountered; for instance, a shaft-blade coupled vibration of a turbine and generator set. Instead of FEM modelling for a global system consisting of main system A and sub system B, an equivalent reduced system is presented. According to the reduction technique, the eigenvalue problem of the vibrating system B is first solved; then, equivalent masses and springs are determined for each corresponding eigenmode of system B. Therefore, the original global system is reduced to system A plus the additional masses representing system B. It is concluded that the reduced model is physically reasonable and numerically accurate enough, even though a simpler program is used for the system A than for the global system A+ B.