High-stress ice fracture and friction

The fracture and friction of ice have been examined under triaxial compression at rates and temperatures for which the deformation behavior is predominantly brittle-elastic. Strength is limited by rapid, unstable fracture which occurs along cleavage planes that experience the highest resolved shear stress in the case of single crystals and in the direction of maximum bulk shear stress for polycrystals, Fracture propagation is possibly associated with the onset of plastic slip or yielding in both cases. Polycrystalline ice frictional sliding at high rates and/or low temperatures appears to be the result of elastically deforming asperities that undergo shear failure. A well-defined frictional law is apparent in which (shear stress) proportional to (normal stress)(2/3), independent of temperature, surface roughness, and sliding rate, provided deformation remains elastic.