Damage and Fracture during Contact between a Spherical Indenter and Ice: Experimental Results and Finite Element Simulations

Abstract

Effective modeling of ice material behavior requires treatment of both damage and fracture. In this paper, a discussion of local ice damage and fracture processes observed during laboratory-scale indentation experiments conducted on unconfined polycrystalline ice using a spherical indenter is provided. Particular emphasis is placed on the interplay between fracture and extrusion processes corresponding to the failure of ice under a single zone of high contact pressure. Simulations have been conducted using a continuum damage mechanics user-material routine in conjunction with element removal techniques to simulate pressure-softening and discrete fracture processes, respectively. Simulation results provide good agreement with test data and provide important insights into interplay between damage and fracture mechanisms associated with compressive ice failure. Finite element modeling was found to work well for modeling pressure softening effects and for replicating the effects of discrete fracture events. For interactions involving multiple failure events, further work is needed to develop models that account for random aspects of fracture associated with flaw structure, contact geometry and the geometry of individual spalls.