Author(s): H. Hendrikse; A. Metrikine; K. -U. Evers
Linked Author(s): Hayo Hendrikse
Keywords: No Keywords
Abstract: An attempt has recently been made to identify the added mass and added damping of level ice in interaction with a vibrating structure. To this end forced vibration experiments were carried out in the ice tank at the Hamburg Ship Model Basin (HSVA) testing facility in Hamburg in August 2011. The test setup consisted of a rigidly mounted cylinder which, connected to an actuator, could be forced to oscillate with different frequencies and amplitudes. The ice indentation velocity was varied between 0.01 m/s and 0.1 m/s during the experiments, where the ice was made such as to fail mainly in crushing. The setup was equipped with strain gauges and laser sensors in order to measure the ice forces and the model displacement respectively. At the icestructure interface a tactile sensor was installed in order to facilitate simultaneous measurement of the ice pressure on the structure. Added mass and added damping parameters have been identified for several cases from the measured force and displacement signals. The presence of negative damping, as is also found from indentation tests with stationary towed cylinders, is reconfirmed in this experiment. Additionally it is found that for low indentation velocities also the added mass can become negative. This new result provides a new angle of approach for the development of predictive models for dynamic ice-structure interaction.