Vibrations of liquid in partially filled rigid horizontal cylindrical tank caused by horizontal and vertical seismic acceleration

As part of the study of seismic effects on the equipment of nuclear power plants, the problem was solved of determining the effect of vibrations of the free liquid level on the steam generator walls, the vibrations occurring in the direction of its transversal axis. The effects of both the horizontal and vertical components of the seismic excitation were taken into account. The solution is based on the so-called pendulum model. The equations of motion for the equilibrium at the pendulum as well as the equations of equilibrium at the frame are given. Numerical calculations revealed that vibrations of the liquid level in the steam generator in the direction of its transversal axis, induced by the horizontal as well as vertical component of the seismic acceleration, give rise to force effects that cannot be neglected even if the liquid vibrations are low. (Z.M.). 2 figs., 9 refs