Wave slamming loads on wave-piercer catamarans operating at high-speed determined by hydro-elastic segmented model experiments
Lavroff, J and Davis, MR and Holloway, DS and Thomas, G, Wave slamming loads on wave-piercer catamarans operating at high-speed determined by hydro-elastic segmented model experiments, Marine Structures, 33 pp. 120-142. ISSN 0951-8339 (2013) [Refereed Article]
Catamaran vessels operating at high-speed can be exposed to deck diving and bow damage and one resolution of this problem is the wave-piercer design of INCAT Tasmania. Owing to the complexity of the unsteady non-linear flow in the bow area during large wave encounter model testing has been undertaken to identify the peak dynamic slam loads on the ship structure. This paper provides
experimental benchmark information relating to the wave slam loads on wave-piercing catamaran ferries. Since the time frames of transient slam loadings and whipping vibration of the entire hull in its first bending mode are similar it is important that the test model replicates the whipping response and therefore needs to be a hydroelastic model. A 2.5m hydro-elastic segmented catamaran model has been developed based on the 112 m INCAT Tasmania wave-piercer catamaran to establish the peak wave slamming loads acting on the full-scale vessel. Towing tank tests were performed in regular seas at a maximumfull-scale operating speed of 38 knots. The model was instrumented to measure the dynamic slam loads acting on the centre bowand vertical bending moments acting in the demihulls of
the catamaran model as a function of wave frequency and wave height. Peak slam loads measured on the centre bow were found to approach the total weight of the model, this being a broadly similar result to the peak loads measured at full-scale. It was found that global dimensionless heave and pitch accelerations peaked in the same range of encounter frequency as did the peak slam load.