Dynamic modeling of cable system using a new nodal position finite element method

The handling of cable systems onboard surface ships and submarines presents a significant technical challenge to design engineers in defense and ocean industries. The current approaches rely heavily on empirical methods and time-consuming/expensive prototype testing. Computer simulation provides a cost effective way to reduce the high risks associated with the design of the cable-towed system. This paper presents a new nodal position finite element method (FEM) to effectively simulate the dynamics of cable system experiencing large rigid body rotation coupled with small elastic deformation. The existing FEM deals with the large rigid body rotation by linearized incremental approximation that is prone to numerical inaccuracies resulting from large 3D rotations. By solving for the position directly instead of indirectly via the displacement, the new FEM does not need to decouple the elastic deformation from the rigid body rotation and thus eliminates the error source arising from the linearized incremental approximation in existing FEM. Analysis results demonstrate that the new FEM algorithm is simple and robust by comparing with numerical benchmark test and experiments including sea trial data. Copyright © 2008 John Wiley & Sons, Ltd.