This paper calculates the distributions of ice pressure and contact area on the ship hull when a ship advances in level ice. The structural response of a simple stiffened panel of the ship hull under the estimated pressure-area relation is investigated using finite element model. The calculated ice pressure-area relations show similar relationship as the measured data, which is the ice pressure decreases with increasing the contact area. The localized deformations and stress distributions of the ship side shell model under the calculated pressure-area relations are strongly depending on the local ice pressure distributions.
For the structural design of the ice-going ship, the local ice force distribution on the ship hull is essential problem. The local ice force distributions measured from the real ship trial are usually estimated by the structural response derived by the strain gauges or the load cells on the plate or the frame constituting the ship structural component (e.g. Frederking, 2003). The estimated ice force distributions from these data has a time and spatial limitation depending on a resolution of the measurement system, the arrangement of the strain gauges and so on. In the model test, Izumiyama et al. (1999) directly measured the ice pressure distribution along the ship hull with the sheet-shaped pressure sensors which installed on the ship outer hull. The pressure sensors can measure the exact location of the ship-ice contact point, the ice force and the ice pressure area along the ship hull. However, there are many uncertainties so that the exact local ice pressure distribution for calculating the structural response have not been estimated due to the complexity of the ice breaking mechanism. Watanabe et al. (1983) and Riska et al. (2002) have investigated the relationship between the ice pressure distribution and the structural response of the stiffened panel.
