Theoretical description of the design of naval structures subjected to dynamic loads: a critical review considering the finite element analysis of exposed decks subjected to the shock wave pressures generated by gunfire (Gun Blast)

Abstract

The structural analysis of exposed decks on military vessels under dynamic loads induced by gun firing represents a challenge of growing relevance in modern naval engineering. Standard NES 154, which for decades has been the de facto reference for the design of weapon-supporting structures, proposes replacing and simplifying the dynamic load caused by the gun blast with a static pressure equivalent to 25% of the gun blast's peak value. This reduction, while operationally practical, it omits critical variables that determine the actual structural behavior: pressure variation over time, fluid-structure coupling, and inertia effects inherent to the transient dynamic regime. This systematic review aims to examine, based on recent literature (2020-2025), the theoretical foundations of design of naval structures under dynamic loads, shock-wave propagation models in free space and over structural surfaces, finite element methods (FEM) applied to nonlinear transient state, and the analysis alternatives to the static simplification specified in NES 154. Methodological gaps have been identified that justify the need to apply transient dynamic analysis using a linear elastic model with small deformations—which can be implemented in platforms such as ANSYS—for the rigorous evaluation of the exposed deck of military ships, such as the Offshore Patrol Vessels (hereinafter OPV-type vessels), equipped with the Oto Melara 76 mm gun. The findings converge on the conclusion that the difference between the safety factors obtained through static approximation (recommended by NES 154) and those derived from dynamic analysis can be significant, with has direct implications for the structural integrity and reliability of military ships.