Stresses in Above‐Ground Storage Tanks Subjected to Flood‐Borne Debris Impact

ABSTRACT The objective of this study is to investigate the structural response of above‐ground storage tanks (ASTs) subjected to flood‐borne debris impact, a critical yet understudied aspect of flood‐induced loading. While past research has extensively examined AST performance under hydrodynamic and hydrostatic loads, limited attention has been paid to debris impact, which can contribute significantly to tank damage during floods. In this study, finite element simulations were conducted using LS‐DYNA to model the effects of debris impacts from typical flood‐borne objects, namely, wood logs and steel pipes, on four ASTs of varying geometries. The models incorporated realistic geometric imperfections, strain‐rate effects, and added mass effects. Parametric analyses were conducted for various debris orientations, impact locations, and tank configurations to assess the resulting stresses in the tank shell. Results showed that for empty case‐study tanks impacted by debris moving at 3 m/s, the maximum von Mises stresses remained below the material yield strength of 250 MPa, and the effective plastic strain remained very low. The highest stress (204 MPa) occurred with head‐on wood log debris when added mass effects were considered. Geometric imperfections, impact location, and contact friction had minor influence on the stress magnitudes in the case‐study tanks. These findings indicate that typical flood‐borne debris, such as wood poles and steel pipes, are unlikely to rupture or cause leakage in ASTs considered herein.