Presentation: 2025 ND EPSCoR Annual conference 

October 21, 2025, NDSU Memorial Union, Fargo, North Dakota

Numerical Investigation for Assessing Seismic Vulnerability of LNG Tanks: Implications for Design Codes and Risk Reduction

Liquefied Natural Gas (LNG) storage tanks are vital components of energy infrastructure, and their seismic resilience is crucial for safety and continuous operation. This study examines the dynamic response of full-containment cylindrical LNG tanks subjected to multiple earthquake ground motions using advanced finite element analysis. The modeling framework employs an Arbitrary Lagrangian–Eulerian (ALE) method to simulate fluid–structure interaction (FSI), capturing the complex coupling between sloshing liquid and the inner steel containment. The outer reinforced concrete (RC) shell is modeled with the Concrete Damage Plasticity (CDP) approach to represent nonlinear behavior, including tensile cracking and compressive crushing. Numerical analyses evaluate transient hydrodynamic pressures, stress distributions, and potential local buckling modes under seismic loading. Results show that the earthquake ground motion characteristics significantly influence the sloshing wave amplitude, frequency, and stress concentrations, particularly near the tank base and lower wall regions. Among the scenarios studied, the Takatori (Japan) earthquake produced the highest hydrodynamic pressure and sloshing wave heights, underscoring the importance of considering varying seismic intensities in design assessments. A comparison with design code provisions reveals notable discrepancies in predicting buckling thresholds and dynamic pressure responses. Based on these findings, a new design equation is proposed to improve the accuracy and reliability of seismic evaluations for LNG storage tanks. This research advances performance-based design methods and offers valuable insights to inform codes and risk mitigation strategies.