29 / 80
29
Annual Report 2016
SAMCoT
IVOS, SAMCoT associated project, has continued its
course since 2015 and achieved a new set of testing and
results in 2016. A new setup was used which provides
higher flexibility to change structural parameters such
as stiffness, geometry and natural frequency. This al-
lowed us to create ice-induced lock-in vibrations under
various conditions with different structures. Similar to
the first tests, all structures were equipped with tactile
sensors to monitor local ice loads.
After a successful first testing phase in 2015, IVOS
conducted a second testing phase in December 2016.
The local load measurements obtained from the
previous test phase have already allowed interesting
observations during ice-structure interactions to be
made, stimulating further tests as well as review
and enhancement of existing theories on ice-induced
vibrations.
A completely new setup is always a challenge (with
an element of risk); therefore, a “pre-test phase” was
conducted in October 2016 to check its functionality,
and several details have been optimized. Next to
cylinders with different diameters and stiffness, a flat
indenter with changing orientation was tested and set
into lock-in vibrations as well.
The data obtained will be meaningful for numerical
model validation, and will provide insight into the diffe-
rences between ice-structure interactions on cylindrical
and flat structures which are still not well understood.
ICE-INDUCED VIBRATIONS OF
OFFSHORE STRUCTURES (IVOS)
Front view of Run 27010; IC
@
20mm/s
Channel after the test