Analysis of methods for the prediction of ice loading on a ship’s hull
Insinööritieteiden korkeakoulu | Master's thesis
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Master's Programme in Mechanical Engineering (MEC)
AbstractThe hull of a ship operating in ice might be exposed to significant ice loading, originating from a complex and stochastic interaction between the hull and the ice. In order to analyze such ice loading, taking into account the stochastic nature of the hull-ice interaction, statistical methods might be used. In this context, the estimation of the local ice pressures on various locations of a ship’s hull is required. This thesis aims to analyze a semi-empirical method known as the event-maximum method, which estimates the maximum local pressures as the function of the contact area and the ice condition. To this end, this study uses the full-scale ice load measurements to determine a new set of curves, which describe the relationship between the contact area and the local pressures. The obtained curves are subsequently compared with the previous studies corresponding curves, which had been obtained from different sets of full-scale ice pressure measurements. In addition, the maximum local pressures obtained from this study are compared with the maximum local pressures obtained using the design curve proposed in previous studies. Furthermore, for studying the effect of the variation of the load height on maximum local pressures, a sensitivity analysis is performed for the bow. The results show that the curves obtained in this study are close to the curves obtained in previous study. Furthermore, the sensitivity analysis shows that the variation of the load height causes small changes in maximum local pressures at the bow. The study shows that the event-maximum method is well-suited for the estimation of the maximum local pressures at all the locations of the hull. This research may help naval architects to design safe and efficient hull structures for Arctic ships.
Thesis advisorKujala, Pentti
ship-ice interaction, probabilistic methods, ice-induced loading, event-maximum method, local ice pressures