Abstract

A numerical method is proposed for the seismic response analysis of rectangular and cylindrical tanks accounting for non-linear hydrodynamic effects. The equations of motion are mapped from the physical to the computational domain by means of a change of variable. The numerical solution is then obtained by means of finite differences. The system of second order equations obtained from the finite difference discretization are linearized using the Newton method and solved numerically by means of the biconjugate gradient method. The numerical formulation was applied to study the response of tanks subjected to ground motion records from the Mexico earthquake of 19 September 1985, obtained in Mexico City. Response results are given in terms of wave height on the liquid surface, and shear force and overturning moment at the base wall, and are compared with those obtained for the linear solution.