Research progress on damage mechanisms of underwater vehicle structures under combined loading from deep-water explosions

To further enhance the survivability of underwater vehicles subjected to the combined loading effects of deep-water explosions, this paper elucidates the influence of hydrostatic pressure on underwater explosion shock wave loading, bubble pulsation loading, and the damage response of typical structures, thereby addressing the limitations of conventional shallow-water explosion theory in the context of deep-water explosion research.

To achieve these objectives, a comprehensive and systematic review of both domestic and international research literature published over the past decade was conducted, with a specific focus on deep-water explosion loading and the corresponding structural dynamic responses. The methodological framework consisted of three integrated phases. First, a systematic literature search was performed across major academic databases using targeted keywords such as 'deep-water explosion', 'hydrostatic pressure effect', 'bubble dynamics', and 'structural damage response'. Studies were screened according to their relevance, methodological rigor, and explicit consideration of water depth as a variable. Second, an analytical framework with water depth as the core variable was established. This framework enabled the categorization and comparative synthesis of results from theoretical models, advanced numerical simulations (employing tools such as AUTODYN, LS-DYNA, and smoothed particle hydrodynamics methods), and experimental investigations (including controlled pressure vessel tests and open-field trials). Third, a meta-analytic technique was applied to extract quantitative trends—such as variations in peak pressure, energy distribution ratios, and plastic strain amplitudes—and to identify qualitative patterns in failure modes. This process facilitated the identification of consistent underlying mechanisms while also revealing key discrepancies among different investigative approaches.

The study demonstrates that water depth serves as a core variable driving the transformation of explosion energy distribution and the dominant damage mechanism. As water depth increases from 0 m to 2000 m, the peak pressure associated with bubble pulsation rises by 50%, whereas the peak shock wave pressure remains largely unchanged. The coupling between high hydrostatic pressure in the deep-water environment and dynamic explosion loading becomes increasingly significant, leading to an expansion of the structural plastic strain zone, degradation of stiffness, and a shift in failure mode from localized damage (such as shell denting and tearing) under shallow water conditions to global damage (such as global buckling and wrinkling).

The enhanced dominance of bubble loading and the coupling effects of static-dynamic loads are identified as the core physical mechanisms intensifying structural damage in deep-water explosions. Finally, a correlation framework between water depth and damage modes is established, clarifying the fundamental distinctions between deep-water and shallow-water explosions. This framework provides clear engineering guidance for the optimal design of protective structures for deep-water underwater vehicles. This study not only advances fundamental knowledge but also provides a practical foundation for optimizing the protective design of next-generation deep-water underwater vehicles. Future efforts should focus on refining coupled theoretical models, validating advanced numerical techniques over a wider range of water depths, and enhancing experimental capabilities to support this critical field of research.