Study on structural damage mechanisms and defence of rectangular closed-section simplified hull girders with thinner plates under near-field underwater explosions

Abstract

Understanding the damage mechanisms of typical ship structures under fatal underwater explosion loads is crucial for developing effective defensive measures. To provide references for enhancing the survivability of ships, this paper conducts analyses of the damage mechanisms of simplified hull girders (SHGs) using a combination of experimental and simulation methods, and proposes targeted structural improvements. Initially, two types of thin-walled rectangular closed-section SHGs are subjected to near-field underwater explosion experiments. Corresponding simulation models are established, and the validity of the computational results is verified. The progressive damage processes of SHGs in hogging and sagging are examined from a structural perspective. Furthermore, the thin-walled plate deformation transfer processes are analyzed. Finally, based on the analyzed damage mechanisms, targeted defensive structures for overall damage are designed. The study results show that enhancing the anti-deformation capability of the upper and lower edges of the side plates can effectively improve the overall bending resistance of the SHG.