Effect of a rotational damper on a moored and articulated multibody offshore system in waves

Abstract

Motions and loads of an articulated and moored floating platform consisting of multiple bodies in waves are investigated through numerical analysis. The wave–structure interaction (WSI) problem is solved using a high-fidelity viscous–flow solver that couples nonlinear rigid body motions, multibody interactions with an internal connection, and mooring dynamics. The study focuses on two modular floating structures (MFSs) connected by a flexible joint, with and without a rotational damper, and positioned using four symmetrical mooring lines. Multibody responses and the corresponding loads acting on the mooring lines and hinged joints are analyzed. Our results reveal that the influence of the damper on heave motions is less significant. Notably, the presence of the rotational damper has a noticeable impact on pitch motions between the two hinged MFSs. Introducing a rotational damper on the flexible joint effectively dampens the highly dynamic pitch motions while not imposing additional loads on the flexible joints.