To reasonably predict the seismic response of the liquid storage tank under different earthquake records, a new mechanical model is proposed based on the equivalent principle of the base shear and the overturning moment. Firstly, the velocity potential of the liquid in the storage tank is introduced by resolving the Laplace equation. Thereafter, the governing equations of motion of a liquid storage tank with base isolation are derived on the basis of Hamilton’s principle. And finally, the dynamic response processes of the liquid storage tanks of different ratios of height to radius by using the existing mechanical models, proposed mechanical model, and three-dimensional finite element model in the software ANSYS are compared. The analysis results show that the proposed mechanical model is stable and reliable whilst the predicted results are highly accurate and effective. Given the high order convective modes, the liquid sloshing height has a delayed effect.
