COMPARISON OF MEASURED AND SIMULATED SHORT TERM ICE LOADS ON SHIP HULL

摘要

Ship operations in ice are increasing as the interest in transport and oil and gas production in the Arctic is increasing. In order to ensure the safety at sea, the structure of ships has to be designed to withstand the ice induced loads on the ship hull. Therefore knowledge on local ice loads on ships is required. The knowledge on local ice loads has been gained through several full scale measurements in the past in which the frames of ships have been instrumented with strain gauges for local ice loads measurements. These measurements are the basis for current structural design methods. Full scale measurements are the only way to gain reliable data on ice loads on ships. However full scale measurements are lacking because they are expensive to obtain and ship specific. Furthermore, full scale measurements are obtained after building of the ship and therefore serve only for future design. Developing a reliable numerical method would enable to estimate the local ice loads in the design phase and improve the structural design of the ship. In order to establish a numerical method for the design, the method has to be validated with the full scale measurements on different ships. In this paper, a recently developed numerical method is compared with the full scale measurements conducted on board the Polar Research and Supply Vessel S.A. Agulhas II in the Baltic Sea during March 2012. Short term local ice loads on a frame are simulated with the numerical method by using the ship parameters, operational parameters and the measured ice conditions during the full scale measurements as an input. The simulated local ice loads at the bow are then compared with the measured local ice loads on the bow frame.