FRACTURE-TOUGHNESS OF FRESH-WATER ICE .2. ANALYSIS AND MICROGRAPHY

Experiments have been performed to determine the effect of loading rat e and temperature on the fracture toughness of freshwater ice. A first paper (Weber and Nixon, 1996) presents the experimental technique and results, while this paper focuses on discussion of the crack tip proc ess zone and fracture surface micrography. A simple method to estimate the size of the process zone will be presented. Also, fracture surfac e micrography will be used to interpret the results of the temperature experiments by considering evidence of dislocation activity in prefer entially oriented grains.