| Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 96 === This thesis deals with the vibration and the stability of a simply supported uniform beam subject to a moving mass at a constant velocity. The governing equations eventually become a periodic time-varying system. Furthermore, the design of dynamic vibration absorber on such a system is explored. In this study, Hamilton’s principle is first used to derive the equations of motion, then, the modes expansion method yields the discrete equation of motions.
In the numerical analysis, Runge-Kutta Method is used to find the dynamic responses and Fast Fourier Transform is used to find the response frequencies. The results show that there is a main response frequency. At low moving speeds, the main response frequency is close to the one as the moving mass fixed at the middle of the beam. As speed increases, the response frequency deviates from it. In the stability analysis, Floquet theory is used to observe the unstable area. The results show that increasing of moving mass also increases the unstable area.
In the end of the research, the problems of a dynamic vibration absorber tacked on-to the system are discussed. A power absorber index is defined to find the best setting frequency of the DVA. A dimensionless best setting frequency for DVA is then developed.
|
|---|
