A wedge-shape ice bar is modeled to simulate an indentation process of an ice sheet moving toward a rigid rectangular leg of a structure. Continuum damage mechanics approach is adopted for description of the transition phase of ice failures due to microcracking. The stress propagation speed is obtained as a function of damage. A finite difference algorithm is developed to solve governing equations on characteristic curves. The results are obtained for different apex angles and compared with those of uniform bar.


Conventional analyses of global and local behaviors of ice sheet in the Arctic region have showed two distinct approaches: continuum and fracturing. In reality, microcracking affects not only local behavior but also global behavior of the ice sheet. The transition from continuum behavior to fracturing behavior is the most difficult problem to be analyzed(Sanderson, 1988). A continuum damage model of ice can be one solution in the prediction of the transition phase in ice failure. Continuum damage mechanics(CDM) has been developed as an intermediate branch between fracture and continuum mechanics. A notable advantage of CDM is that it can describe easily and theoretically the initiation of structural failure of inelastic materials. The approach has been effective especially for creep-behavior materials. Fig. 1 illustrates the basic concept of damage mechanics (Chaboche, 1984). Up to the very beginning of micro cracking, the whole body can be treated as a continuous medium. Here, damage is a measure of decreasing stiffness due to microcracking. Basically, this paper is an extension of our previous results of the case of a uniform bar(Shin and Karr, 1990a). One of the unrealistic results for the uniform bar was a long extent of stress and damage propagation.

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