Experimental Evaluation of Curved Aluminum Structures Subjected to Underwater Explosions.

Background: This research arises from the concern of damage to submersible marine structures such as underwater vehicles and pipelines and the need to understand dynamic failure. This work focuses on analyzing the dynamic bubble-to-structure interaction of curved metallic plates subjected to air-backed underwater explosive loading. Objective: This research aims to expand the current understanding of gas bubble formations during nearfield underwater explosion events with experimental analysis. Methods: The experiments were performed in an underwater explosive facility using high-speed cameras to measure full-field displacement and velocities during deformation through a digital image correlation technique. In addition, during the experiments, pressure transducers were used to record the pressure pulses emanated from the explosive charge. Experiments were performed for two plate curvatures (112 and 305 mm) and three standoff distances from the plate's surfaces (55, 73, and 110 mm) for each curvature. Results: The experiments show that deformations are higher if the explosive standoff is smaller or the structural radius of curvature is higher. In addition, the increase in structural deformation also leads to distorted bubble shapes that increase their repulsion from the structural specimen and decrease the bubble collapse period. Conclusions: Nearfield bubble dynamics are highly sensitive to the proximity of nearby structures and the compliance of such structures. Though they have higher deformations in general, complicated structures may be able to mitigate bubble attachment or jetting for specific explosive charges. [ABSTRACT FROM AUTHOR]