DYNAMIC BUCKLING TEST OF MODIFIED 1/10 SCALE MODEL OF CYLINDRICAL WATER STORAGE TANK

摘要

This study reports on the dynamic buckling experiment of a 1/10 reduced scale model of a large-scale cylindrical water storage tank by using a shaking table, and the buckling analysis by using both the simplified method and the finite element method. The dynamic buckling experiment is performed by using the reduced scale tank model whose initial imperfection has been measured. The tank model is filled with water up to 95% of the full level, and puts 200-weight on its top, overcoming the response reduction induced by the oval-type vibration. The sinusoidal waves are used as the input. As a result of the experiment, the bucking occurs on the tank and plastic deformation is observed on the side and bottom of the tank. Two methods of the buckling analysis are carried out. At first, the buckling load is estimated by using a simplified method adopted in the current Japanese guideline The analytical result shows this method is conservative despite using the tank with initial imperfection. Secondly, the static buckling analysis with the finite element method is conducted. There is an issue how to treat the dynamic fluid pressure distribution of the contained water in the tank with regard to the static analysis, because the coupling between fluid and structure cannot be taken into consideration. In this study, the distribution of the dynamic fluid pressure is calculated in accordance with the Fischer's method. The buckling load calculated by using the dynamic fluid pressure distribution agrees with that of the experiment approximately. Therefore, it is appropriate to apply this proposed static analytical method to seismic design.