Determining the Damage Mechanisms for Buoyancy Materials of Deep-Sea Manned Submersibles

Zhang, Y.; Ding, Z.; Wang, Y.; Zhao, Q., and Qin, S., 2019. Determining the damage mechanisms for buoyancy materials of deep-sea manned submersibles. Journal of Coastal Research, 35(5), 996–1002. Coconut Creek (Florida), ISSN 0749-0208.Deep-sea manned submersibles are important platforms for ocean exploration, and their structural reliability is critical to the personal safety of the crew. In particular, the buoyancy materials of deep-sea manned submersibles are vital parts because they provide the necessary buoyancy for submersible operations. This paper first describes the overall damage of the buoyancy materials used in the deep-sea manned submersible Jiaolong that accumulated over a large number of research expeditions during years of services. The causes of the damage are analyzed by computational fluid dynamics (CFD) methods. Because Jiaolong's buoyancy materials are secured to its structural frame by bolts, the external forces that act on the submersible are concentrated on these bolts. Those external forces include the wave forces that act on the submersible when it floats on the sea surface and the buoyancy material shrinkage that occurs because of changes in environmental pressure and temperature during submarine operations. Finally, several suggestions are provided for improving the design and operation of deep-sea submersibles.