8000 doctoral degrees at TU Delft

News - 20 January 2017

Hendrikse researched ice-induced vibrations, originating from dynamic interaction between the ice and offshore structure, that can result in high global peak loads and significantly contribute to the fatigue of structures. 

Offshore developments in ice-covered waters, such as the Arctic Ocean or Baltic Sea, have received increasing attention from the petroleum and wind power industries over the past decade. Sustainable developments in such waters can contribute to a balanced energy future provided that the deployed offshore structures are designed to be safe.

The potential development of ice-induced vibrations has to be considered in the design of bottom founded offshore structures with a vertically sided waterline cross-section subject to ice. A governing theory which can explain the development of ice-induced vibrations has not yet been defined, despite several decades of research. As a consequence the tools required for detailed design of structures subject to ice-induced vibrations are not yet available. The main objective of this study is to define a physical mechanism which can explain the development of ice-induced vibrations and is consistent with existing experimental and full-scale observations. 

A literature study and new experiments in the large ice-basin at HSVA in Hamburg have resulted in the identification of key features of the interaction process. A new theory has been proposed, namely that the variations in the contact area between the intact ice and structure govern ice-induced vibrations. These variations result from the velocity dependent deformation and failure behaviour of the ice.

Based on the theory a phenomenological model for the prediction of ice-induced vibrations has been developed of which the predictions have been shown to be consistent with experimental observations. Additionally, the limiting effect of ice buckling on ice-induced vibrations has been studied and practical application of the model illustrated on the basis of simulation examples.

8.000 doctoral degrees

The first doctoral degree ceremony at TU Delft took place in 1906, and was for Nicolaas Söhngen and his thesis, ‘The creation and disappearance of hydrogen and methane under the influence of organic life’. That year, just two doctorates were conferred, and it was not until 1925 that the one hundred mark was reached. After that, it became an ever-more frequent event. The seven thousandth doctorate was conferred in May 2014. 

More information

For access to theses by the PhD students you can have a look in TU Delft Repository, the digital storage of publications of TU Delft. Theses will be available within a few weeks after the actual thesis defence.