Abstract
The rocking motion of tanks due to earthquakes causes the uplift and partial of large deformation of the tank bottom plate that has been considered to contribute to the various damage of the tanks. For analyzing the stress of the tank bottom plate numerically, this paper develops the analytical finite ring element with effects of the large deformation. The ring element is defined as a semi-analytical model. Fourier series give its circumferential displacement function, while polynomial gives its radial displacement function. For evaluating analytical accuracy of the proposed method, numerical results are compared with experimental ones that measure deformation of circular aluminum plate subjected to hydro static pressure.