ABSTRACT
Hull fatigue comprises low and high frequency vibration. The latter is caused by whipping and springing, in which waves excite the flexural bending modes of the hull girder. In this text, strain data collected on board a slamming-prone vessel navigating a Southern Ocean storm is analysed. Attention is given to the effect of slamming on the accrued fatigue. The geometry of the superstructure is such that it contributes to the longitudinal strength of the vessel. The rationale behind sensor placement in a situation where the maximum stress location does not align with location of maximum loading is detailed. The fatigue damage components are computed using cycle counting and Palmgren Miner’s linear damage accumulation theory. The contribution of the high frequency component to the total damage is found to reach a peak of 69%. A slamming detection algorithm is used to prove a positive association between whipping and high frequency fatigue.
