Searched for: author%3A%22Hammer%2C+T.C.%22
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Hammer, T.C. (author), Puolakka, Otto (author), Hendrikse, H. (author)
A modeling approach to simulate ice-induced vibrations of vertically sided offshore structures in ice tank experiments is presented. The technique combines replica modeling with the preservation of kinematics during ice-structure interaction. The technique was chosen based on the theoretical understanding that ice-induced vibrations are...
journal article 2024
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Petry, Alice (author), Hammer, T.C. (author), Polojärvi, Arttu (author), Hendrikse, H. (author), Puolakka, Otto (author)
Increased activity in planning offshore wind farms in the northern Baltic Sea has renewed interest in studying the effect of ice cones on ice failure mechanisms. In preparation for future experiments with steep ice cones, preliminary ice basin experiments were performed at the Aalto Ice and Wave Tank to investigate how model ice fails against a...
conference paper 2023
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Hammer, T.C. (author), Hendrikse, H. (author)
Drifting sea ice failing in crushing against vertically-sided offshore structures can cause ice-induced vibrations. Offshore structures are typically founded on slender structures to minimize the load effect of waves and currents. In combination with large top masses, those offshore structures often provide sufficient compliance for ice-induced...
conference paper 2023
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Owen, C.C. (author), Hammer, T.C. (author), Hendrikse, H. (author)
Cyclic crushing experiments with a haversine velocity waveform were performed on passively confined, freshwater columnar ice specimens for a variety of velocities and frequencies. The aim of the experiments was to study the ice deformation and failure behavior in crushing when loaded at a predefined displacement pattern closely resembling the...
journal article 2023
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Hammer, T.C. (author), Willems, Tom (author), Hendrikse, H. (author)
For offshore wind farms which are planned in sub-arctic regions like the Baltic Sea and Bohai Bay, support structure design has to account for load effects from dynamic ice-structure interaction. There is relatively high uncertainty related to dynamic ice loads as little to no load- and response data of offshore wind turbines exposed to...
journal article 2023
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Hammer, T.C. (author), Hendrikse, H. (author)
The effect of misalignment between wind- and ice loading direction on the development of ice-induced vibrations of offshore wind turbines has been investigated experimentally. In the experiments a hybrid test setup was used to study the structural response to combined loading from physical model ice and numerically applied wind. The...
journal article 2023
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Owen, C.C. (author), Hammer, T.C. (author), Hendrikse, H. (author)
A series of ice penetration tests with a rigid structure, with controlled oscillation, and with a single-degree-of-freedom structure were performed to investigate the peak load-velocity dependence for ethanol-doped model ice during a test campaign at the Aalto Ice and Wave Tank. For the rigid structure and controlled-oscillation tests, the...
journal article 2023
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Hendrikse, H. (author), Hammer, T.C. (author), van den Berg, M.A. (author), Willems, Tom (author), Owen, C.C. (author), van Beek, C. (author), Ebben, Nick J.J. (author), Puolakka, Otto (author), Polojärvi, Arttu (author)
Basin tests were performed at the Aalto Ice Tank to gather data on ice-structure action and interaction from ice failing against a vertically sided cylindrical pile. The tests were performed with a real-time hybrid test setup, which combined physical and numerical components to simulate a range of test structures in real-time. The dataset...
journal article 2022
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Hornnes, Vegard (author), Hammer, T.C. (author), Høyland, Knut V. (author), Hendrikse, H. (author), Turner, Joshua (author)
In bodies of water where ice is not an annual occurrence, such as in the Southern Baltic Sea, the design of offshore wind turbines is complicated by the difficulty involved in estimating the relevant ice parameters (thickness, velocity, and strength) and their corresponding probabilities of occurrence (return periods). In this paper, the use of...
conference paper 2022
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Owen, C.C. (author), Hammer, T.C. (author), Hendrikse, H. (author)
For the topic of predicting ice-induced vibrations of vertically sided offshore structures, the rate-dependent ductile-to-brittle transitional deformation and failure behavior of ice is critical but remains superficially understood. To investigate this knowledge gap, a test setup has been designed which allows for in-situ crossed-polarization...
conference paper 2022
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Hammer, T.C. (author), Owen, C.C. (author), van den Berg, M.A. (author), Hendrikse, H. (author)
Ice-induced vibrations of offshore wind turbines on monopile foundations were investigated experimentally at the Aalto Ice Tank. A real-time hybrid test setup was developed allowing to accurately simulate the motion of a wind turbine in interaction with ice, incorporating the multi-modal aspects of the interaction and the effect of simultaneous...
conference paper 2022
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Hendrikse, H. (author), Hammer, T.C. (author), Owen, C.C. (author), van den Berg, M.A. (author), van Beek, C. (author), Polojärvi, Arttu (author), Puolakka, Otto (author), Willems, Tom (author)
With the recent surge in development of offshore wind in the Baltic Sea, Bohai Sea and other ice-prone regions, a need has arisen for new basin tests to qualify the interaction between offshore wind turbines and sea ice. To this end, a series of model tests was performed at the Aalto ice basin as part of the SHIVER project. The tests were aimed...
conference paper 2022
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Landmann, Jannis (author), Hammer, T.C. (author), Günther, Henning (author), Hildebrandt, Arndt (author)
The concept of floating vegetation-based islands for the bioremediation of aquatic ecosystems is well known. Less so, their hydrodynamic capabilities regarding the damping performance, positional stability and water-structure interactions. To this end, physical model tests with fully organic, reed-based gabions were carried out in a large...
journal article 2022
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Høyland, Knut V. (author), Nord, Torodd Skjerve (author), Turner, Joshua (author), Hornnes, Vegard (author), Gedikli, Ersegun Deniz (author), Bjerkås, Morten (author), Hendrikse, H. (author), Hammer, T.C. (author), Ziemer, Gesa (author)
In the FATICE project we have addressed the fatigue damage on fixed offshore structures exposed to drifting ice. This is an important challenge in the development of energy production from offshore wind in the Baltic and involves at least five element: a) define ice statistics, b) predict the structural response (ice-structure interaction...
conference paper 2021
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Hammer, T.C. (author), van Beek, C. (author), Koning, J.R.A. (author), Hendrikse, H. (author)
With the ongoing development of offshore wind in cold regions where the foundations are exposed to sea ice, there is a strong need for data to validate the numerically predicted dynamic interaction between ice and structure used for design. Full-scale data is non-existent and only a limited number of experimental campaigns in ice tanks have been...
conference paper 2021
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