Ice action on compliant structures: Laboratory indentation tests

This experimenal research addresses the dynamic ice-structure interaction of marine structures. The main objective was to obtain data on the phenomenon known as steady-state vibration of vertical offshore structures. Such data is needed while researcers develop numerical and simplified models of the vibration. A further objective was to find data on ice-induced vibrations of conical structures. A common belief has been that ice can not create significant vibrations on conical offshore structures. Recent full-scale data has shown that this assumption is not correct. Hence, the present project aimed at obtaining laboratory data on this kind of vibrations. The third aim of the project was to demonstrate that additional structural damping can be used to mitigate the dynamic response caused by ice actions. Tests were done at the ice basin of the ARCTECLAB using the carriage of the ice basin. An experimental structure was installed on the carriage and penetration tests were done on three sheets of columnar grained ice. The dynamic properties of the structure were modified during the test series. Two different indontors were used, a vertical cylinder and a cone. This test report provides detailed descriptions of the test set up and the test programme. The main results are also shown in terms of the measured time signals. The report serves as a background document for more detailed analysis and subsequent exploration of the data.