ABSTRACT
In this paper, the behaviors between the vessel and underwater slope of a artificial proctective island during the collision events are analyzed using the Coupled Eulerian-Lagrangian(CEL) scheme. To consider the large deformation including the shear failure of soil, the Eulerian domain are used for the model of the soil and water, and the colliding vessel is modeled as the Lagrangian domain. Series of analyses are performed for the parameters of the vessel and the slope. The vessel parameters considered in the analysis are bow angle, stem angle and impact velocity. The gradient of the slope, the friction coefficient between the bow and the slope and soil strength are considered as parameters of the slope. For each parameter, the dissipated collision energy and the collision force are estimated from the behaviors of vessel, and the energy dissipation mechanism is identified in terms of the soil deformation. The collision force are assumed as a exponential function, and the effects of the parameters are estimated. As a result, only two parameters, such as the gradient of slope and the friction coefficient between vessel and soil, can affect to the exponential coefficient of the function. The dissipated energy by soil can be estimated adequately by this relationship. The relationship between the volume of the soil pushed out by the bow and the dissipated collision energy is estimated as linear function. This relationship is independent from the magnitude of the collision energy and affected more by the friction coefficient and the soil strength than the parameters of vessel.
