Dent analyses of horizontal tanks caused by hemispherical fragment impact under different filling conditions

In explosion accidents within tank farms, fragments may unexpectedly impact tanks, causing dents or even cracks. The damage caused by impacts on filled tanks differs significantly from that on empty tanks. To investigate the degree of risk of tanks under various filling conditions after being impacted, this study established an experimental setup for fragment impact on horizontal tanks and developed a corresponding fluid-structure interaction numerical model. This model was used to analyze the dent deformation behavior and energy distribution mechanisms of tanks under different filling conditions. The results indicate that the dent deformation can be categorized into bulging deformation and dishing deformation. Under the same impact velocity, tanks filled with liquid or pressurized compared to empty tanks result in more localized deformation, with increased bulging deformation and reduced dishing deformation. This will cause water tanks and pressure tanks to be more prone to perforation failure than empty tanks. A method for predicting dents and impact forces caused by hemispherical fragments impacting horizontal tanks was proposed, providing support for fracture judgment of tanks post-impact.