An extensive series of drop impact tests were carried out by the Arctic and Antarctic Research Institute (AARI) on natural ice in the late 1960s and by the National Research Council of Canada (NRC) on laboratory ice in the late 1980s. Spherical impactors of radii 286 mm and 100 mm and masses ranging from 33 kg to 300 kg were used. Impact velocities ranged from 0.6 to 5.6 mls. Measurements of accelerations of the impactor allowed ice resistance and penetration to be determined. The data from both test locations were analysed using the Kheisin and Kurdyumov "hydrodynamic model" of impact of a rigid body on ice. The "ice impact crushing strength", analysed by applying the "hydrodynamic model" to all the data, showed consistency and similar trends. Impact strength decreased with increasing velocity and increasing ice temperature. A velocity dependent "ice impact crushing strength" is suggested as a modification to the "hydrodynamic model".
The impact of ships with floating ice is a controlling factor in Arctic navigation. To understand the local loads generated on ship hull structures by these ice impacts, various means have been used. Another approach has been to carry out tests under controlled field or laboratory conditions to obtain a material property, an "impact strength" of the ice, and incorporate this strength property into a theory to predict ice impact pressures on ship hulls. The first comprehensive experimental study of the impact of a rigid spherical body against ice was conducted by the Laboratory of Ship Performance in Ice at the Arctic and Antarctic Research Institute over the period 1967–1969 (Likhomanov and Kheisin, 1971). The primary measurements were acceleration of the body and the depth of penetration into the ice. Based on these tests, the "hydrodynamic model" of impact on ice was developed.
