Measurements of high amplitude/low cycle fatigue of sea ice in conjunction with the characteristic length of sea ice, temperature and salinity profiles and acoustic emissions

The high amplitude/low cycle fatigue properties of sea ice in situ at high strain were investigated by developing a cantilever system of sea ice beams and using hydraulic equipment to exercise these beams to determine the rheological properties of sea ice in situ. This allows the mechanical behaviour to be determined under a variety of various loading conditions and different ice types (i.e. very cold ice and warm ice). A published constitutive equation for sea ice relates stress, strain and strain rate and measurements were used to test the equations relevance for in situ ice in the hope that it may become used routinely to solve ice engineering and geophysical problems. The characteristic length of sea ice was determined by taking ice cores at various distances apart on an exponential scale (i.e. 1, 2, 4, 8, 16, 32....) to know if the properties of ice change over the length of a beam being tested and over an area where a large number of beams are being tested. Temperature and salinity profiles of the ice cores were collected also. Acoustic emissions were monitored in conjunction with the fatigue experiments to determine the nature of the failure of the ice and the relationship between stress and strain in a cantilever beam.