Interfacial crack propagation induced by scraper action on ice

This paper is concerned with the problem of interfacial crack propagation between a layer of ice and its substrate induced by a scraper action on the ice. We consider a layer of ice of uniform thickness bonded to a flat surface. There exists an initial crack generated by radio-frequency induction heating at the ice-substrate interface. The ice is treated as an elastic medium. Two types of loading condition are considered, namely, the longitudinal compression due to a flat head scraper moving with constant speed and the transverse lift due to the penetration of a sharp blade with constant speed. In this analysis, the effect of the propagation of stress wave is neglected. However, the kinetic energy induced by a growth in crack length and the application of an end displacement is included. A nonlinear initial value problem is formulated based on the principle of balance of energy. Numerical results are obtained by the Runge-Kutta method. The buckling and crushing of ice due to longitudinal compressive stress brought on by the action of a flat head scraper and the flexural stress at the crack tip due to penetration of a sharp blade at the interface are investigated. An analogous problem of crack propagation due to an indentation of a wedge on a large specimen is also discussed.