Serviceability Properties of Solid Buoyancy Materials for Deep-Sea HOV

Studying the evolution characteristics of damage strength and water absorption behavior of hollow glass beads solid buoyancy materials used for manned submersibles in the hyper-pressure environment will help people to understand the damage mechanism and induced mechanism of buoyancy materials for manned submersibles. To explore the influence mechanism of different pressure, temperature, loading rate and load cycle times on deformation, failure, and water absorption behavior of solid buoyant materials, hydrostatic pressure tests of solid buoyant materials under different conditions are conducted in this study. Based on the test data, the nonlinear characteristics of mechanical properties and water absorption behavior of two buoyant materials are obtained. The results show that the water absorption characteristics of solid buoyant materials are affected by hydrostatic pressure, and the water absorption characteristics increase exponentially as the hydrostatic pressure increases. The loading rate insignificantly affects the compressive strength and water absorption characteristics of both materials. Ambient temperature has a great influence on water absorption characteristics and failure strength of high-strength solid buoyant materials. After cyclic loading, the properties of buoyant materials decreased, and X-ray micro-CT showed that the internal hollow glass beads had a good shape and no significant change in the glass beads breakage rate. The change of solid buoyancy material properties is mainly due to the change of resin base material properties, resulting in material aging and performance attenuation. The research results are helpful to further explore the fracturing evolution and water absorption behavior of solid buoyant materials and then play a guiding role in calculating the counterweight of manned submersible operation and performance prediction and maintenance of buoyant materials for manned submersibles.