Rheological damping of slender rods

Abstract

Efficient and accurate modelling of mooring and cable systems for Floating Offshore Wind Turbines are a key factor in the coupled dynamic analysis for the realistic assessment of such floating structures. In order to improve the modelling of the mooring and cable systems, a new extension of the slender rod finite element model proposed by Garret with the inclusion of rheological damping is presented. The model takes into account the damping produced for the rod material in both the axial and the bending forces. Derivation of the axial and bending damping forces is presented and assessed in terms of the critical damping. The implementation of the model is presented and tested through three verification simulations and two validation examples, which show a good agreement when comparing with experimental results and prove the capacity and robustness of the model.