From observations and recorded data it is concluded that the contact consist of a narrow line where the melting is attained at high indentation rates. The theoretical analysis and simulation of experiments indicates that the ratio of shear strength to contact pressure controls the fractal behaviour of ice crushing. The contact pressure and shear strength are related to the indentation velocity. As the indentation rate increases the ratio of shear strength to contact pressure decreases causing finer fragmentation of the crushed ice. At present the 2-D model predicts an upper limit of the ice load similar to the Morgan-Nuttall formula for shear failure of an ice sheet with a friction-less indentor.
The ice failure mechanism close to the contact has been studied in a series of small scale crushing tests at relatively high indentation velocities. An iterative numerical model based on successive shear failure was used to predict the crushing behaviour. The model parameters and the initiation of vertical cracks has been evaluated using fracture mechanics. From observations and recorded data it is concluded that the contact consist of a narrow line where the melting is attained at high indentation rates. The theoretical analysis and simulation of experiments indicates that the ratio of shear strength to contact pressure controls the fractal behaviour of ice crushing. The contact pressure and shear strength are related to the indentation velocity. As the indentation rate increases the ratio of shear strength to contact pressure decreases causing finer fragmentation of the crushed ice. At present the 2-D model predicts an upper limit of the ice load similar to the Morgan-Nuttall formula for shear failure of an ice sheet with a friction-less indentor.