Author(s): Annika Hoderath; Gesa Ziemer
Linked Author(s):
Keywords: No Keywords
Abstract: Pressure-area curves are a common implement for the design of ice breaking ships in order to assess the local loads that will act on the hull. Design curves based on the maximum event method as defined by Jordaan et al. (1993, “Probabilistic Analysis of Local Ice Pressures”, ASME J. Offshore Mech. Arct. Eng., 115, pp. 83-89) help to predict the probability of exceedance of certain load on the area in question, which is crucial for the structural design. Yet, these curves are mainly based on ship shaped structures and have been obtained from ship rams in ice. In order to obtain probabilistic design curves for continuous ice contact, Neumann et al. recently developed a new definition of temporal events to be used for the creation of design curves using the basic maximum event method (2015, “A novel data processing method for ice pressure statistics”, Proc. OMAE, OMAE2015-41822). A promising approach to derive data with sufficient detail is utilization of scale model tests with tactile sensors which allow high resolution pressure mapping. The applicability of model tests as a basis for pressure-area design curves for fixed structures based on the max-event definition by Jordaan and Neumann et al. is subject of this study. A model of the Norstr"omsgrund lighthouse has been tested in HSVA’s Large Ice Basin and was equipped with tactile sensors. Full scale data from this lighthouse is available as well. A comparison of the obtained design curves from model scale and full scale measurements shows that model tests are a promising technique for assessment of local design pressures by combination with full scale values. This paper describes the adjustments of event definition needed to obtain meaningful data from the model tests, issues and uncertainties during test analysis, and findings from validation with full scale data.
Year: 2016