抄録
A large amplitude excitation experiment was performed for a thin cylindrical water storage tanks in order to investigate the vibration characteristics. In addition to beam vibration, oval vibrations with the circumferential wave number n=12, 14 or 16 were observed. The acceleration level which generates an oval vibration was proportional to the increasing rate of magnitude of response acceleration of the tanks. It was found that one of generation mechanisms of the oval vibrations was a super summed and differential harmonic vibration having [l/2(p_1i+p_2 )] pattern.
