59371 Motion of a Flexible Hose attached to an Underwater Vehicle System(Flexible Multibody Dynamics)

Abstract

The behavior of a flexible hose connected to an underwater vehicle is changed variously according to the motion of the underwater vehicle. Such a case, telecommunication lines protected by the hose is likely to take place serious problems like cutting or connecting error. So, it is very important to accurately analyze and predict a motion of the flexible hose in underwater, because large deformation motions of the hose in axial and normal direction determine vehicle's driving conditions. In real situation, it is impossible to carry out an experiment with a real object for the reason why the length of the hose is about 60〜100 m. Therefore, the behavior was predicted using computer simulation. In this paper, the underwater vehicle was considered as rigid body that has 6 degrees of freedom and was driven by rudder angle and surge propulsion. And to model the hose, ANCF was adopted to consider the flexibility of hose, in which the formulation was highly enough to express both large deformation effect and various forms of behavior. In ANCF, the concept of continuum mechanics was introduced to derive the tensile and bending stiffness of the cable. Hence, nonlinear effects of elastic forces could be considered more effectively. Also, because fluid drag force does take a greatly significant role at both the vehicle and the flexible hose, the effect was imposed.