Sympathetic underwater implosion in a confining environment

Abstract

An experimental study is conducted to investigate the phenomenon of sympathetic underwater implosion of cylindrical metallic shells in a confining environment. Two aluminum 6061-T6 implodable volumes with different collapse pressures are placed inside a confining tube with one end open to the environment and are hydrostatically loaded upto the weaker implodable volumes' critical collapse pressure. Experiments show that implosion of the weaker implodable volume (critical pressure = c P ) inside the confining tube leads to the subsequent sympathetic implosion of the stronger implodable volume (critical pressure =1.2 c P ). Implosion of the weaker implodable volume produces strong oscillating water hammer waves with 1.6 c P peak over-pressure, which initiates the implosion of the stronger implodable volume. Pressure histories recorded within the confining tube indicate that the sympathetic implosion of the stronger implodable volume generates low pressure high frequency implosion waves. The superposition of the low pressure waves with the high pressure water hammer waves mitigate to a great extent the later cyclic water hammer loading within the confining tube.

Advances in naval composite and sandwich structures for blast and implosion mitigations

“…Kishore et al 8 investigated the response of a composite shell to the implosion of a nearby weaker shell. Contrary to the study by Gupta et al 94 the composite cylindrically tubes were placed parallel to each other in a free field (without a confining tube). The damage mechanism and pressure pulse generated are two major parameters widely studied for implosion phenomena.…”

Effects of ring stiffeners on the underwater collapse behavior of carbon/epoxy composite tubes

“…Second, a high-amplitude pressure wave is emitted when the walls of the tube come into contact during the buckling process, and the surrounding fluid is arrested. 2…”

“…Second, a high-amplitude pressure wave is emitted when the walls of the tube come into contact during the buckling process, and the surrounding fluid is arrested. 2 Research interest in the implosion phenomena of structures has existed since the mid-1900s for collapse behavior studies, 3,4 space vehicle design, 5 and offshore pipelines. 6 However, researchers have called for a more comprehensive understanding of the implosion phenomena after high-profile research accidents in recent decades.…”

Underwater Implosion and Energy Mitigation of Hybrid Glass-Carbon Composite Shells

“…First, the cylinder becomes unstable and collapses inwards at an increasing velocity, causing a drop in local pressure as the surrounding fluid accelerates along with the structure. Second, a highamplitude pressure pulse is emitted when the cylinder walls make contact, resulting in an abrupt change in the momentum of the surrounding fluid [2]. This pressure wave has been shown to induce damage to neighboring structures [3][4][5].…”