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SAMC
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T • Annual report 2012
Fig. 17. Damage to the steel structure caused by the ice: a)
at full-scale (S. Hänninen), b) in laboratory.
The tests were conducted in the ice basin at Aalto Uni
versity, Finland, where ice masses were towed into a
moored structure with a deformable panel mounted in
the impact zone.
Both the ice and the structure experienced notable de
formations during impact. The characteristics of the ice
impact zone and panel deformations compared fairly well
with the data from full-scale observations (see Fig. 17).
We believe these experiments are the first to focus
exclusively on the coupled damage behaviour of both
ice and steel, with our findings demonstrating realis
tic damage to the steel plates. However, more damage
to the steel structures, including stiffening systems,
would further enhance the knowledge of this complex
coupled deformation process. Based on the knowledge
learned during the Aalto experiments, new experiments
are planned in 2013/2014 with a focus on obtaining more
data on ice-steel interactions producing larger defor
mations than achieved in the Aalto experiments.
Friction of Sea Ice on Sea Ice
Knowledge of ice friction plays an important role in
a number of Arctic engineering applications. For in
stance, it affects the designs of icebreakers and their
performance in ice and it is necessary for the calcula
tion of ice loads on sloping offshore structure construc
tions.
Additionally, friction is a fundamental process during
the brittle compressive deformation of cold ice. Friction
is the largest sink of energy during the rafting and ridg
ing processes of sea ice. Therefore, the results of the
numerical simulations describing these processes are
significantly affected by the choice of the input for the
friction coefficient.
“During my field study with first-year ice (Barents Sea
and fjords at Spitsbergen) and second-year ice (Northeast
Greenland), I did tests where ice blocks were slid along
tracks using a pulling mechanism, a linear actuator,” says
Sergiy Sukhorukov, a SAMCoT doctoral student.
b)
a)
Fig. 18. Experiment set-up for friction tests.