Impact penetration of cylinders in soft seafloor sediments

The plastic limit solutions provide a basis for estimating impact penetration of cylinders in soft seafloor sediments. A simplified analytical framework was developed for interpretation of the experimental data. The model examines the resisting force due to sediment shear resistance estimated from the plasticity theory. A law is used in the analysis, in which sediment shearing resistance increases with the logarithm of penetration velocity. Atterberg limit tests showed the sediments to have liquid limits equaling 44 to 45 and plastic limits equaling 20 to 22. A program, consisting of two series of tests, was conducted to investigate the effects of a number of variables including weight and impact velocity. The strain-rate multiplier that achieves optimal agreement between predicted and measured penetrations in the cylinder penetration tests match the strain-rate multiplier deduced from the variable rotation rate miniature vane tests. The additional post-impact penetration also plays an important role for cylinders impacting the seafloor at low velocities.

Impact penetration of cylinders in soft seafloor sediments Academic Article