Transient dynamic slam response of large high speed catamarans

In order to optimise the structural design of lightweight high speed vessels knowledge is required of the effect of sea loads on their structure. Wet deck slam events are of particular importance for high speed catamarans. This paper reports on the use of dynamic finite element analysis to investigate the transient response of a large high speed catamaran to an extreme asymmetric wet deck slam. Such an extreme slam occurred whilst extensive full scale hull stress, motion and wave measurements were being conducted on a 96m catamaran. Dynamic finite element analysis, including the fluid-structure interaction, has been utilised to develop an extreme slam dynamic load case which may be utilised in the design process. Results from this analysis are compared with the stress levels obtained through applying the Det Norske Veritas (DNV) longitudinal bending moment (sagging) rule load case.