単結晶氷の破壊じん性値に及ぼす結晶軸方位の影響

概要

論文の詳細を見る
The effect of the direction of the crystal axis (C-axis) on fracture toughness of single-crystal ice specimens was investigated by the three-point bending test at -10℃. The loading rate K^^._1 was about 200 kPa√<m>/s. Four types of single-crystal ice specimens were used in which the C-axis direction of the crystal was placed at an angle θ equalling 0°, 45°(I), 45°(II) and 90°, respectively, to the notch plane. These specimens have a sharp edge notch made by pressing the edge of a razor blade on the bottom of the saw-cut slot. In advance of the test using single-crystal ice specimens, the effect of pressing the razor blade on fracture toughness was examined using columnar grained ice specimens under the loading rate K^^._1 ranging from 1.0 to 1.0×10^4 kPa√<m>/s at -10℃. The effects of loading rate K^^._1 on fracture toughness of both blade-pressed specimens and blade-molded specimens under K^^._1 > 30 kPa√<m>/s were very small and the difference botween them was approximately 10 kPa√<m>. Fracture toughness values of θ=0°and θ=90°specimens were nearly equal, K_C]_<50%>=110.5 kPa√<m>, and those of θ=45°(I) and θ=45°(II) specimens were nearly equal too, K_C]_<50%>=99.2kPa√<m>. The fracture toughness of columnar grained ice specimens estimated from that of single-crystal ice specimens was higher than the experimental values.
一般社団法人日本機械学会の論文
1991-05-25