Seismic Performance Assessment of Cylindrical Liquid-Filled Storage Tanks Considering Fluid–Structure Interaction

Cylindrical steel storage tanks play a vital role in petrochemicals, oil refineries, power plants, and storage systems for liquefied natural gas (LNG) and other hazardous materials. These structures are highly susceptible to local instability that can cause failure of the tank–liquid system and disrupt industrial operations. Ensuring their safety and reliability requires advanced dynamic modeling, seismic design, and structural health monitoring. This study investigates the seismic behavior of cylindrical storage tanks, focusing on fluid–structure interaction (FSI) and the nonlinear response to seismic base excitations. The study also conducts a parametric analysis to assess the impact of liquid levels and seismic input accelerations on sloshing dynamics and structural response. Results from the finite-element analysis (FEA) are validated against experimental test data, demonstrating strong agreement and confirming the accuracy of the finite-element (FE) modeling approach. The results indicated that the experimentally measured shear force was 47.30 kN, whereas the numerical model predicted 44.27 kN, corresponding to a percentage difference of approximately 6.4%. Findings from the parametric study revealed that the hydrodynamic pressure changed significantly as the applied peak ground acceleration (PGA) input values varied. Tanks subjected to 0.45g exhibited slightly greater deformations compared with 0.40g, whereas 0.31g produced similar responses to those at 0.40g. Hydrodynamic pressures reached 149.3 kPa at 0.45g, 94.6 kPa at 0.40g, and 76.3 kPa at 0.31g, indicating reductions of 36.60% and 48.69%. For Tank 3 during the 1940 El Centro earthquake, the maximum sloshing height reached 970 mm at 22.6 s for the 91% fill level, with lower volumes producing 780 mm at 16.3 s and 760 mm at 51.7 s. This research provides critical insights into the seismic behavior of storage tanks and offers practical recommendations for designing resilient systems that mitigate risks associated with seismic activity.