Experimental study on the response of multi-layered protective structure subjected to underwater contact explosions

This paper presents the results of an experimental work on the response of multi-layered protective structures subjected to underwater contact explosions. Multi-layered structures are used in anti-explosive design to resist underwater explosions and protect the equipment in some important ship compartments. The target experiment model is designed as a three-compartment box, an air, a fluid and another air compartment, which is made of four plates with thickness 4 mm that resist the propagation of damage. A series of experiments with increasing dynamite charge weight were conducted on this multi-layered structure. The damages and pressures of the test specimens were obtained. In general, it is shown that large damages and plastic deformations happened in the test structures, especially for the plate in contact with the dynamite. With the increase of the charge a trend of increasing damages in the outer and intermediate plates was observed, but the increase was small for the inner plate. Some important factors in plate damage are analyzed and the role of the compartments with different medium in the damage and energy dissipation is discussed. It is found that the multi-layered structure can resist the explosive loading very effectively.