Transient Response of Coated Submersible Hull to Deep Underwater Explosion

Underwater explosion (UNDEX) can severely damage warships and submarines, so improving shock resistance ability of such weapons is of great importance. However, studies on enhancing shock resistance ability of submerged structures are limited. In this paper, the shock mitigation effects of cellular cladding coated on the submersible hull subjected to combined loads of hydrostatic pressure and shock wave are analyzed. First, one-dimensional analytical model is proposed to reveal the shock mitigation mechanism of cellular claddings. The pressure at fluid-structure interface and the thickness of cellular foam needed to fully dissipate shock energy are obtained. Then, the finite element method is employed to investigate the transient response of bare/coated submersible hull subjected to UNDEX. The results indicate that the cellular cladding coated on the pressure hull is very effective on reducing hull deformation, velocity and acceleration response if the cladding is not fully densified. Otherwise, the stress enhancement appears when the cladding is fully densified prematurely, which will weaken the shock mitigation effects. The research results are useful in designing surface shields for submersible hull so as to enhance its resistance to underwater shock damage.