Comparison and validation of numerical methods to assess hydrodynamic loads on mechanical coupling of multiple bodies

In the design of articulated systems, accurate prediction of loads on mechanical couplings is important for the dimensioning of the coupling, as well as an assessment of local and global structural loads. The paper studies a twofold pushing convoy in shallow water. Several numerical approaches for the prediction of articulation loads are compared with each other and with model tests. Kinematic constraints are applied to couple the bodies at articulation points to model hinge and rigid mechanical couplings. For comparison, contact elements are also used to simulate hinges. Depending on the articulation model numerical computations are conducted in frequency or time domain. Comparison between different numerical methods and with model experiments shows that the proposed methods can predict articulation loads with sufficient accuracy for design purposes. The frequency domain approach with kinematic constraints seems more suitable to compute the hinge coupling forces than time-domain simulations with contact elements.