Dynamic internal explosion load characteristics of a warhead and structural damage analysis

Objective To investigate the coupling between blast waves and fragments generated by a warhead detonating inside a ship compartment under dynamic conditions, and to examine their effects on structural damage modes.

Methods A fluid–structure interaction model was established, and the finite element method−smoothed particle hydrodynamics (FEM−SPH) approach was employed to simulate warhead fragmentation and fragment dispersion. The numerical method was validated against experimental data. Parametric analyses were performed for different detonation locations and initial velocities. Structural damage was assessed in terms of pressure response, fragment kinetic energy, structural deformation, and breach area.

Results Compared with static detonation, dynamic detonation significantly altered the loading characteristics. An increase in initial velocity accelerated the rise in forward peak pressure while reducing the backward peak pressure. Fragment kinetic energy increased substantially with initial velocity and was derived primarily from the initial kinetic energy. The breach area ratio of the forward-facing outer plate increased from 3.11% to 18.14%.

Conclusion Fragment-induced perforation facilitated pressure relief and mitigated pressure concentration at compartment corners, shifting the dominant failure mode from corner tearing to corner plastic deformation accompanied by mid-span tearing. Dynamic detonation was more likely to cause through-penetration and progressive tearing, with the resulting damage jointly governed by detonation location and initial velocity.