Impact Energy Absorption Behavior of Unequal Strength Liquid Storage Structures Under Drop Hammer Impact

To enhance the impact resistance and protective performance of ship double-bottom liquid tanks, a liquid storage structure with unequal panel strength was designed. Drop hammer impact experiments and finite element simulations were carried out under ten different working conditions. Based on the experimental and numerical findings, the failure morphology, dynamic response, energy absorption characteristics, and protection mechanisms of the structure were systematically analyzed. By quantifying the plastic limit ratio between the front and rear wall panels, the relationship between strength matching and energy dissipation was revealed. The findings demonstrate that reducing the strength of the rear wall panel promotes large-deflection plastic deformation, which facilitates directional energy dissipation and reduces both the deformation and energy absorption of the bottom panel. Furthermore, the strength matching between the front and rear panels causes asymmetry in the dynamic response during impact. Increasing the plastic limit ratio enhances the protective capability of the structure, providing a valuable reference for the design of unequal-strength double-bottom liquid tanks in ships.