A Kane-based time domain hydrodynamic analysis method for hinged multi-floating bodies under irregular wave conditions

Abstract

To better investigate the hydrodynamic responses of hinged multiple floating body system in irregular waves, a novel Kane-based time domain model is established and the associated calculation program is developed in conjunction with the potential theory and the catenary theory. The reduced Kane equations suitable for the dynamic response of moored multi-floating body system with hinges in irregular waves are firstly deduced, and then an experiment of hinged floating bridge performed in a wave tank is briefly introduced. Following the validation of the Kane-based model based on the comparisons between the predictions and the observations of the model test in several irregular wave conditions, an investigation of the influence of wave parameters in JONSWAP spectrum on the dynamic response of the system is further conducted. The associated results indicate that the heave motions, the pitch motions and the vertical connector loads of the hinged pontoons decrease nonlinearly with the growth of peak frequency under general sea conditions, while the peak enhancement factor has little influence on the dynamic responses of the hinged floating bridge. In addition, the first pontoon in the hinged floating bridge shows the greatest motion responses, and more attention should be paid to its dynamic response during analysing the security of hinged floating bridge.