SIMULATION OF UNDERWATER BLAST LOADING ON NAVAL SHIP STRUCTURES USING AUTODYN
Keywords:
Underwater explosion,, UNDEX,, bubble pulsation,, explicit dynamics, fluid–structure, interaction,, Johnson–Cook model,, naval structures.Abstract
Naval vessels are highly susceptible to underwater explosions (UNDEX) generated by torpedoes,
mines, and depth charges. Non-contact underwater explosions produce shock wave loading, gas
bubble oscillation effects, hull whipping, and structural damage. Due to the high cost and risk of
full-scale experiments, numerical simulation is essential for evaluating structural response. This
study presents a nonlinear explicit finite element simulation of underwater blast loading on a
frigate-class naval vessel using ANSYS AUTODYN. Both the initial shock wave and secondary
bubble pulsation phases are modeled, incorporating fluid–structure interaction (FSI). Material
behavior is represented using the JWL equation of state for TNT and the Johnson–Cook model for
ship steel. Results demonstrate that secondary bubble pulsation significantly contributes to hull
whipping and structural stress development. The developed methodology provides a robust
framework for naval shock-resistance design.
