233 Study on the Ovaling Vibration Phenomena Observed at the Upper Side Wall of a Thin Cylindrical Liquid Tank

Abstract

When a thin walled cylindrical liquid storage tank is exposed to a very large seismic base excitation, buckling phenomena such as elephant foot bulge at the bottom portion and nonlinear ovaling vibration at the upper portion may be caused. In the previous study, elephant foot bulge phenomena and the liquid pressure effect were investigated. In this report, nonlinear ovaling vibration phenomena were investigated based on the dynamic buckling tests using scale models of thin cylindrical liquid storage tanks for the nuclear power plants. The mechanisms and the effect of vertical excitation and liquid sloshing were studied and discussed.