Abstract
Some nonlinear vibration responses were observed in cylindrical tank with water on shaking table driven by periodic sinusoidal wave. The linear vibration theories never explain occuring these vibration phenomenon. It is reported that they might be caused by initial imperfection of cylindrical shell. Assuming that these responses were caused by geometrical nonlinearity of the system with elastic container and water , we have been studying these nonlinear responses from both theory and vibration test. Here, we report subharmonic vibration responses that branch out on periodic stationary response of the vibration system. They make instability regions on response curves, where subharmonic vibration responses become significant vibration. We show several mechanisms that generate the instability regions of subharmonic vibration on response curves.
