Fracture and Damage During Dynamic Interactions Between Ice and Compliant Structures at Laboratory Scale

Recent laboratory experiments have been carried out to study the compressive failure of confined polycrystalline ice during indentation by structures of varying compliance at different temperatures. The experiments presented in this paper focus on the indentation of ice using a single indenter mounted on a compliant beam. From these tests it was observed that the stiffness of the structure plays an important role in the development of cyclic loading patterns. Fracture and damage processes in the ice have been linked with the observed loading patterns and failure frequencies as high as 240 Hz have been linked to crushing and extrusion of ice. Temperature and loading rate were observed to significantly influence whether or not cyclic loading occurred and which ice failure mechanisms dominated the interaction process. When cyclic loads were observed, their frequency was found to exhibit a positive relationship with the indentation rate, as well as the structural stiffness. Based on this work it is concluded that both structural feedback and the mechanics of ice failure play an important role in determining the nature of dynamic interactions between ice and compliant structures.